{152.5 u... éxueurfihfi ‘ i a . s r S: . ..V. w. ‘ "acid... .fiéwfi .. gr. .0. “M... . 4......1. 5: .1! l: A I 32517 3...“... h. e..x....i.. in. . € .. I, .. etc...” ,.....é. Eat... . t» .1 1.. :nnfiffiné V 3.7: E 2.2:? s - :. . JV . . . , ‘ . , :: LIBRARY Michigan State University MICHIGAN STATE UNNERlSITY LIBIHARIES 31293 02048 PLACE IN RETURN BOX to remove this checkout from Your record. TO AVOID FINE return on or before date due. MAY BE RECALLED with earlier due date if requested. DATE DUE DATE DUE DATE DUE 11100 cICIRCID‘OmmS-p.“ THREE ESSAYS IN APPLIED ECONOMICS By Te-Fen Lo A DISSERTATION Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Economics 2000 ABSTRACT THREE ESSAYS IN APPLIED ECONOMICS By Te-F en L0 This dissertation consists of three essays. Chapter 1 is “Charter School Location”, Chapter 2 is “Are Urban Districts Inefficient?” and Chapter 3 is “Migration and Economic Growth”. Chapter 1: Charter schools represent one part of the larger movement toward parental choice in the US. school system. The intention of these programs is to use market mechanisms to improve school efficiency, innovation, and program variety. This study provides evidence on these issues using data on Michigan and California. We regress the number of charter schools in each school district on the characteristics of students and public schools in those same districts. The results indicate that more charter schools locate where populations are diverse in terms of race, income, and adult education levels. We interpret this as demand for horizontal differentiation, reflecting both preferences for homogeneous student populations and preferences for specific education programs. In both states, charter school location is negatively related with public school test scores. This implies that parents pay attention to test scores (vertical differentiation), even though these scores may be imperfect signals for school performance. Most differences in results across the two states can be attributed to differences in state policies regarding the granting of charters and the funding of public schools. Chapter 2: We use the stochastic production frontier model to estimate efficiency for public school districts in Michigan. Three different specifications for the efficiency term including the half-normal, truncated normal and exponential are used. We find that urban school districts are significantly less efficient than the non-urban school districts. Besides, the school districts with higher percentage of children in poverty, higher percentage of children who are black, larger enrollment (large districts), and larger total expenditure are less efficient. Moreover, the school districts with less schooling of the adult population are also less efficient. The by far biggest urban school district, Detroit, is relatively inefficient in the production of schooling in our model, especially for science test, however, it is not the worst one. The average measure of efficiency of Detroit is roughly twice as large as the least efficient one. Chapter 3: We use the dynamic panel data model to explore the relationship between the migration rate and the economic growth. We find that high level income instead of high growth rate of income attracts people move in, and the inflow of migrants also contributes to the economic growth. In addition, the level of per capita income have significant dynamic properties, that is, its current level is significantly related with its previous value. However, we do not find significant dynamic property for the migration rate. We also find the urban population and the crime rate have significantly negative impact on the migration rate. C0pyright by Te-Fen Lo 2000 Dedicated to My Dearest Parents, Chien-Nan Lo and Ju-Hua Tsai, for their love, encouragement, and all kinds of support. ACKNOWLEDGMENTS I would like to begin by thanking my adviser, Professor Gerhard Glomm for the completion of this dissertation. I always think my self as very fortunate to have been under his instruction. His guidance and encouragement have helped me through his program. Moreover, he has not only been my advisor in economics, but also been an advisor in my life. He has given me the warmest concern and advice I have ever had during my study in the United States. I also thank Professor Steven Matusz, who has given me constructive guidance during in study of economics, and helped improve the quality of my dissertation. I also appreciate Professor John Giles’s insightful comments. In addition, my thanks go to my co-author, Douglas Harris, for his invaluable comments and warm fi'iendship. I want to give my special thanks to my parents, Chien-Nan Lo and Ju-Hua Tsai. Without their love, encouragement, and financial support, I would never have arrived at this point. Many of my friends and fellow graduate colleagues have also contributed in different ways. I thank Jenhei Chen, Yi-Yi Chen, Bih-Shiow Chen, Chiung-Ying Cheng, Hung-Jen Wang, and Chung-Jung Lee for sharing the happiness and life/academic experiences with me. There are still a lot of people who have helped me, but not mentioned in the list. I appreciated what they have done for me with deep gratitude. vi TABLE OF CONTENTS LIST OF TABLES ............................................................................................................. ix LIST OF FIGURES ........................................................................................................... xi CHAPTER 1 CHARTER SCHOOL LOCATION ................................................................................... 1 I. Introduction ............................................................................................................. 1 II. An Informal Theory ............................................................................................... 6 III. Data and Methodology ....................................................................................... 10 IV. Results ................................................................................................................ 18 V. Conclusion ........................................................................................................... 36 Appendix A: Summary Statistics (Michigan) ........................................................... 38 Appendix B: Summary Statistics (California) .......................................................... 39 Appendix C: The Educational Production Frontier Function (Michigan) ................ 40 References ................................................................................................................. 42 CHAPTER 2 ARE URBAN DISTRICTS INEFFICIENT? ................................................................... 46 I. Introduction ............................................................................................................ 46 II. Methodology ........................................................................................................ 50 111. Result .................................................................................................................. 56 IV. Conclusion .......................................................................................................... 78 Appendix A: Public School Districts with Missing Data ......................................... 80 Appendix B: MLE Estimates for Different Models for Math Test ........................... 81 Appendix C: 20 Most Efficient Public School Districts ........................................... 82 Appendix D: Counts for Appearing in the 20 Least Public School Districts ........... 85 References ................................................................................................................. 89 CHAPTER 3 MIGRATION AND ECONOMIC GROWTH ................................................................. 92 I. Introduction ........................................................................................................... 92 II. Literature Review ................................................................................................ 94 III. Methodology of the Estimation ........................................................................... 99 3.1 Dynamic Panel Data Model ............................................................................ 99 vii 3.2 Endogeneity Problem .................................................................................... 101 3.3 Choices of Instrumental Variables ................................................................ 103 3.4 Statistical Tests ............................................................................................. 105 IV. Specification of the Model ............................................................................... 106 V. Regression Results ............................................................................................ 111 VI. Conclusion ....................................................................................................... 126 Appendix: Data Definition and Source ................................................................... 128 References ............................................................................................................... 13 1 viii LIST OF TABLES CHAPTER 1: CHARTER SCHOOL LOCATION Table 1: Charter School Growth in Michigan ..................................................................... 3 Table 2: Mean of Independent Variables Categorized by Number of Charter Schools in School Districts (Michigan) .................................................................................. 12 Table 2 (cont’d) ................................................................................................................. 13 Table 3: Mean of Independent Variables Categorized by Number of Charter Schools in School Districts (California) ................................................................................. 14 Table 3 (cont’d) ................................................................................................................. 15 Table 4-1: Regression Results for Michigan .................................................................... 21 Table 4-1 (cont’d) ............................................................................................................. 22 Table 4-2: Regression Results for California .................................................................... 23 Table 4-2 (cont’d) ...... ' ....................................................................................................... 24 Table 5: Regression Results Omitting Potential Outliers for Michigan ........................... 33 Table 6: Regression Result with Border Districts for Michigan ....................................... 35 Table A: Summary Statistics (Michigan) ......................................................................... 38 Table B: Summary Statistics (California) ......................................................................... 39 Table C: The Educational Production Frontier Function (Michigan) ............................... 40 CHAPTER 2: ARE URBAN DISTRICTS INEFFICIENT? Table 1: Average Test Score along Different Dimensions ............................................... 48 Table 2: Data Statistics Summary ..................................................................................... 58 Table 3: OLS Estimates for Different Models .................................................................. 61 Table 4: Summary of Five Types of Regressions for Model 1, 2, and 3 .......................... 62 Table 5: Estimated Efficiency Distribution for Different Models .................................... 65 Table 6A: 20 Least Efficient Public School Districts for Math ........................................ 67 Table 6B: 20 Least Efficient Public School Districts for Science .................................... 68 Table 6C: 20 Least Efficient Public School Districts for Graduation Rate ...................... 69 Table 7: Relative Measure of Efficiency for Detroit ........................................................ 71 Table 8: Correlation Coefficients between Educational Achievement and Efficiency 73 Table 9: Comparison of Estimated Efficiency (HST Math) ............................................. 75 TablelO: MLE Estimates for Technical Efficiency Models for Math Test ...................... 77 Table A: Public School Districts with Missing Data ........................................................ 80 Table B: MLE Estimates for Different Models for Math Test ......................................... 81 Table Cl: 20 Most Efficient Public School Districts for Math ....................................... 82 Table C2: 20 Most Efficient Public School Districts for Science ................................... 83 Table C3: 20 Most Efficient Public School Districts for Graduation Rate ...................... 84 Table D: Counts for Appearing in the 20 Least Public School Districts .......................... 85 Table D (cont’d) ................................................................................................................ 86 Table D (cont’d) ................................................................................................................ 87 CHAPTER 3: MIGRATION AND ECONOMIC GROWTH Table 1: Data Statistics Summary by Decades ............................................................... 108 Table 2A: Migration Equation in Different Estimation Methods .................................. 113 Table 2B: Growth Equation in Different Estimation Methods ....................................... 114 Table 3A: GMM Estimations with Different IVs for Migration Equation .................... 118 Table 3B: GMM Estimations with Different IVs for Growth Equation ........................ 119 Table 4A: Alternative Specifications for Migration Equation ....................................... 121 Table 48: Alternative Specifications for Growth Equation ............................................ 122 Table 5: “Quasi-Simultaneous” Migration and Growth Equation .................................. 125 LIST OF FIGURES Figure 1: Horizontal and Vertical Differentiation of Schools ............................................ 8 xi CHAPTER 1 CHARTER SCHOOL LOCATIONl I. Introduction Before 1990, choice in the American education system was limited to assigned public schools and private schools. Since then, there has been a significant restructuring. Many states have allowed public school choice, allowing students to attend the public schools outside the districts in which they reside. Voucher plans in Milwaukee, Cleveland, San Antonio, and Florida have further expanded these choices to include private schools. These small-scale programs appear to be precursors to widespread choice programs, such as those proposed in Michigan, California, and other states. A third instrument of providing greater school choice is the charter school system. Charter schools are publicly financed and often subject to less regulation than traditional public schools. Some oversight is usually administered by third parties, including universities or state government agencies, rather than local school boards. Charters receive a fixed amount per student enrolled. However, in contrast to public schools, they ' We thank participants in association meetings of the ABA, Econometric Society, and Public Choice, as well as seminars at the Federal Reserve Bank of Chicago, Michigan State University, the University of Michigan, and the University of Kentucky. We especially thank Bih-Shiow Chen, Julie Cullen, Tom Downes, David Figlio, Larry Kenny, Bob Rasche, Peter Schmidt, and John Strauss for useful comments. Financial support for this project from the Business College at MSU is gratefully acknowledged. do not receive a separate allotment for capital expenditures.2 In addition, operating revenues in charter schools are sometimes as low as 50 percent of neighborhood public schools with an average of about also 80 percent (Finn, Manno, and Vanourek, 2000). Therefore, total spending per student is usually much lower in charter schools compared with nearby public schools. The charter school movement is the most rapidly developing part of the US. school choice movement (Paris, 1998). By the end of 1994, eleven states had adopted charter programs. By 1999, thirty-three states had charter policies, yielding over 1,700 charter schools and 350,000 enrolled students (Finn et al, 2000). In Michigan, the charter school growth was similarly rapid, as indicated in Table 1. 2 Most public school districts can raise capital funding through local property tax levies. Arizona is a slight exception to the rule for charter policies, allowing charter start-up grants up to $100,000. However, this is quite small compared with total required capital costs for most schools. Table 1: Charter School Growth in Michigan Number of Charter YEAR 30110015 in Dim“ 94-95 95-96 96-97 97-98 98-99 0 545 527 508 495 487 1 10 21 35 43 47 2 o 3 6 9 12 3 0 2 3 4 4 O 1 1 1 2 5 0 0 1 2 2 7 0 1 0 0 0 1 3 O O 1 0 0 21 0 0 0 1 0 36 0 O O 0 1 Total Chalrthelrl Schools 10 44 78 108 137 Total ScholsilI District in 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 Perhaps the most compelling argument for school choice in general, and charter schools in particular, is that it will improve schooling by increased reliance on market mechanisms. One argument here is that students will “vote with their feet” for a better alternative school if charter school productivity is not sufficiently high. The market thus imposes discipline on the charter schools. Only good schools will survive. Peterson (1999) finds some support for this view in his review of research on recent, small-scale voucher programs. However, Bettinger (2000) finds that charter schools are not any more productive than public schools. A second argument is that charter schools may improve productivity in the traditional public schools since they stand to lose enrollment, and hence state ftmding, to the charter schools. If this efficiency argument is valid, we expect to find a negative relationship between the number of charter schools and public school performance as measured by productive efficiency within each school district. Hoxby (1994, 1997) finds some evidence for this hypothesis in her studies of competition among private schools and public school districts. A third aspect of efficiency relates to the Tiebout hypothesis, which roughly states that pe0p1e will receive their optimal bundles of government-provided goods if there are many options to choose from and free mobility across jurisdictions. These bundles include the level of local taxation, private school tuition, school performance (vertical differentiation), the type of education being provided (horizontal differentiation), and other amenities. In the case of education, the less perfect is the sorting, the more likely it is that parents will seek other bundles when given alternatives. There is anecdotal evidence that school choice produces schools with specialized curricula and homogeneous student bodies within schools. For instance, the El-Hajj Malik EL-Shabazz Academy in Lansing, Michigan describes its mission as to "serve students using a holistic, Afrocentric curriculum." More generally, 70 percent of all charter school students in Michigan are minority compared with 22 percent of public school enrollment.3 In California, Grutzik, et al (1995) show that “the communities surrounding charter schools are primarily white and have income levels at or above the city and county averages.” Wells et. al. (1996) comes to a similar conclusion, as do other survey-based studies. These outcomes are apparently similar in other countries that have implemented expansive school choice programs.4 In this paper, we address the question whether charter schools do indeed locate in those district where the lack of Tiebout sorting has provided for inefficient outcomes. What are the criteria which charter schools use to make their location decisions? Why might the demand for these schools be greater in some districts than others? For a given demand, what factors influence the supply of charter schools? Do charter schools indeed enter in districts where there are few existing alternatives and imperfect Tiebout sorting? To help answer these questions, we assemble data for all charter schools in Michigan and California, and match each charter school with the public school districts in which they locate. We then regress the number of charter schools in a district on the student and public school characteristics of those same districts. The econometric methodology we use is similar to the one used by Downes and Greenstein (1996), using a statistical model of count data advanced by Hausman, Hall and Griliches (1984) and Cameron and Trivedi (1986). 3 These results come from a study commissioned by the State of Michigan: Public Sector Consultants and MAXIMUS (1999). The results are similar in Arizona, where the numbers are 6 percent and 4.3 percent respectively (Gifford, Ogle and Solmon, 1998). ‘ England, Chile, China, Sweden, New Zealand, South Africa, and the Czech Republic are a few examples. See Harris, Oliver, and Plank (2000) for discussion of these countries. For a description of differences across US. states, see Wohlstetter et. al (1995), Nathan (1996), and Mintrom (1998). Downes and Greenstein study entry (location) by privately fimded schools in California. Bettinger (2000) and Filer and Munich (2000) estimate regressions similar in form to those estimated here. The Bettinger paper also relates to charter schools in Michigan, but his main purpose is to obtain instruments for other regressions that study the impact of charter schools on public school performance. Most of the variables we find to be important are excluded in Bettinger’s regressions. Filer and Munich’s specification is more similar to those used here, but he studies new choice-based schools in the Czech Republic. These authors also exclude a large number of variables that we find to be important, but they do find that charter school location is negatively related with a measure of public school efficiency. In Section II, we provide an informal theory of charter school location based on product differentiation. We describe our data in Section III. Empirical tests of our hypotheses are reported and discussed in Section IV. II. An Informal Theory The evidence above suggests that charter school entry is closely related to product differentiation, including both horizontal (h) and vertical (v) dimensions. Common examples of vertical differentiation (quality) in education include graduation rates, value- added, and the proportion of kids going on to college. In most markets, inputs would not be considered an aspect of quality because more productive inputs are reflected in better outputs and higher prices. However, there are many reasons to believe that the price-quality relationship is rather weak in education. First, dependence on the tax system means that non-consumers are paying most of the cost. Second, the movement toward state level funding may be weakening the connection between local taxation and local school funding. Third, information problems may prevent parents from being able to observe actual school quality. These three facts imply that it may be reasonable to interpret input levels as signals of public school quality. We consider student-teacher ratios, expenditure per student, teacher salaries, and special education expenditures. There are also various dimensions of horizontal product differentiation. These are dimensions along which preference heterogeneity generates disagreement among consumers over what is best. Some consumers may prefer an academic curriculum in high school, while others favor more vocational training. Other consumers may favor schools with racial and ethnic diversity, while others may favor homogeneity. Some favor authoritarian schooling by Catholic nuns, while others favor schooling in which children are free to determine their own rules of conduct. Ideally, the location of schools ought to be considered as the outcome of a location game such as in Hotelling (1929) or Prescott and Visscher (1977). In these papers, location is an outcome of a game played by profit-maximizing firms. Unfortunately, the objective functions for public and private schools are controversial.5 Instead of fully specifying such a location game and characterizing the equilibrium location, we only illustrate potential outcomes of such games. 5 See, for example, Manski (1992) and Nechyba (1996). In Figure 1, product differentiation is shown in h-v product space. This space is n-dimensional, where n is the number of product differentiation dimensions. Household preferences are distributed over the h-v space. The small open circle represents the preferred bundle of an individual person, assuming that person has to pay for the full cost of education. Small closed circles represent schools of which there are three types: public schools (1,, private schools P,, and charter schools C ,. Figure 1: Horizontal and Vertical Differentiation of Schools O O c. O 0 P2 0 C U’ U’ 713 \ / O ‘\ 0 C3 The parent illustrated in Figure 1 can choose any school in the space, but C ,, P2, and U 3 most closely match the parent’s preferences. If all schools did charge full tuition, then we would expect the person to locate at the nearest school in the h-v space. However, the actual funding system includes tuition only at private schools. Therefore, if P, charged high tuition, this option would be eliminated from consideration, leaving C , and U 3, which would provide similar satisfaction at a much lower price. While the above discussion is framed in the language of horizontal product differentiation, we will carry out our econometric work using heterogeneity of tastes. Actual measures of product differentiation, such as the amount of time spent teaching foreign languages, are not available. Therefore, we assume that variation in tastes will give rise to variation in education programs. Public school education programs are chosen by school boards and superintendents for entire districts, therefore, we expect relatively minor variations in product differentiation across public schools within a district. Other models in which public and private schools co-exist, such as the one studied by Epple and Romano (1996), predict that private school quality is higher than public school quality. In addition, horizontal differentiation among the private schools is much greater than among the public schools, providing for the possibility of elite schools with high high-tuition and religious schools with low tuition. As in Prescott and Visscher (1977), we assume that a charter school needs to attract a sufficient number of customers in order to cover fixed costs. It appears in Figure 1 that this is best accomplished by locating away from public and private schools in the h-v product space. However, if only private schools charge tuition, then charter schools may seek to provide education similar to private schools, but free of charge to consumers. Therefore, charter schools may instead try to locate very close to private schools in the product space. In any case, the location of charter schools in the h-v space is dependent upon the characteristics of both public and private schools in the district. III. Data and Methodology In this section we describe our data and the hypothesized relationships between the independent variables and charter school location. All of our data describing public school districts comes from the Departments of Education in Michigan and California. The data on charter schools in Michigan come from the Michigan Association of Public School Academies (MAPSA). The data on California charter schools comes from the Califomia Department of Education. The data on demographic variables comes from the School District Data Book (SDDB), which includes US. Census Bureau data organized by school district. The Michigan sample includes more than 500 observations in each regression specification, out of a total of 555 districts in the state. None of the missing district observations contains a charter school. However, our samples in California are in the range of 288-350 district observations, which is substantially lower than the total number of districts.‘5 Approximately 60 of the 142 districts that contain charter schools are among the list of missing observations, though none of the missing observations contain more than one charter school. All missing observations for both states are due to missing data in the original sources listed above. The unit of observation is the school district. In addition to simplifying the analysis, this approach is appropriate because school policies are set at the school district level. In addition, it is difficult to obtain data at the school level. We use the following ‘5 The actual total number of districts in California varies from year to year, but is approximately 1,000. 10 variables: 1) wealth/income as measured by median household income and the poverty rate; 2) ethnic composition of the population; 3) adult (parent) educational attainment; 4) geographic characteristics, such as area and the enrollment density of the district; 5) performance of the public schools measured by outputs, such as test scores, graduation rates, and productive efficiency; 6) public school inputs, such as student-teacher ratios; 7) charter school revenue (state grants) and costs (teacher salaries); 8) the degree of competition from private schools.7 Summary statistics are provided in appendices A and B. In Table 2 and Table 3 below, we exhibit public school characteristics by the number of charter schools per district. 7 At least three of the variables discussed above are measured with error: teacher salaries, graduation rates, and the number of private schools. We tried various symmetric truncations, but found that the results were unaffected. ll Table 2: Mean of Independent Variables Categorized by Number of Charter Schools in School Districts (Michigan) Number of Charter Schools 0 1 2 3 Number of Observations 487 47 12 4 Med. House Value 54.4400 62.6596 53.1362 59.4318 Per Capita Income 12.4307 13.6903 12.83 83 15.7198 Med. Household Income 29.2252 31.6506 27.7818 33.3838 Percentage of Children in Poverty 14.8747 13.1036 21.0569 16.3991 Percentage of Children Black 2.6253 4.9382 16.5913 34.9468 Percentage of Children Hispanic 2.2202 2.8294 4.9671 1.9740 Herfindahl Index for Race 88.5989 85.6163 74.4901 56.2649 Percentage of Adult with 12 Grade 23.6570 20.9840 23.1694 19.3347 Percentage of Adult with High School 38.1048 35.7185 30.1879 26.2820 Percentage of Adult with Some College 26.2057 28.5187 30.5313 31.5413 Eigfi‘r‘age 0f Ad‘m With Bacmlo’ Degree °’ 12.0325 14.7739 16.1115 22.8420 Average Years of Schooling 13.0095 13.2473 13.3456 13.8080 Herfindahl Index for Education 30.5036 29.2565 28.2192 27.2992 MEAP Math Score 4th Grade 43.2593 44.5915 38.8917 34.0250 Graduation Rate 90.2330 80.8489 83.6250 65.4500 Total Expenditure Per Student 4.3025 4.5489 4.9903 6.3618 Sgregangxeiesnpecial Educational Expenditure 0.3 1 62 0.3 57 6 0. 5 5.7 6 0.4449 Pupil-Teacher Ratio 20.1948 19.5957 20.8333 17.7500 Average Teacher Salary 30.5072 33.1776 35.1267 39.1403 K-12 Enrollment Density 51.6359 45.5082 122.7717 189.7679 Number of Private Schools 1.4262 1.9574 5.5000 10.5000 Total K-12 Enrollment 2.2858 3.7169 7.5739 10.1568 Gr. Rate of K-12 Enrollment -0.1121 0.5445 -0.9812 0.4128 Percentage of Public School located in City 3.3223 10.5910 36.4355 25.0000 Table 2 (cont’d) Number of Charter Schools 4 5 36 Number of Observations 2 2 1 Med. House Value 77.1520 52.9955 25.2940 Per Capita Income 14.0100 12.2060 9.4430 Med. Household Income 26.7145 26.7460 18.7420 Percentage of Children in Poverty 24.3284 25.2006 44.2895 Percentage of Children Black 30.4542 25.9369 82.0884 Percentage of Children Hispanic 8.3750 9.6727 3.2848 Herfindahl Index for Race 47.8377 44.9284 69.2901 Percentage of Adult with 12 Grade 17.8227 21.7313 37.1489 Percentage of Adult with High School 23.0214 26.9645 28.3550 Percentage of Adult with Some College 27.9106 32.7880 25.5750 :eirglzgrage of Adult with Bachelor Degree or 312453 18.51 62 8.9211 Average Years of Schooling 14.2547 13.5494 12.6753 Herfindahl Index for Education 34.2620 26.2948 29.1771 MEAP Math Score 4th Grade 42.5500 30.3000 27.3000 Graduation Rate 69.6500 34.6000 71.6000 Total Expenditure Per Student 5.9510 5.0685 5.2930 Sgregzficeiesnpecial Educational Expenditure 0. 5234 0.71 68 0.61 09 Pupil-Teacher Ratio 18.5000 21.5000 22.0000 Average Teacher Salary 34.0570 31.7525 36.2440 K-12 Enrollment Density 114.6518 227.7712 510.1699 Number of Private Schools 14.0000 23.0000 98.0000 Total K-12 Enrollment 14.6515 26.4940 183.1510 Gr. Rate of K-12 Enrollment -0.6721 -2.1684 -0.5748 Percentage of Public School located in City 98.3333 69.4444 94.5946 13 Table 3: Mean of Independent Variables Categorized by Number of Charter Schools in School Districts (California) Number of Charter Schools 0 l 2 3 4 5 Number of Observations 683 73 1 1 7 2 2 Med. House Value 161.0317 155.5765 193.4620 166.0547 194.9715 143.8660 PerCapitaIncome 15.9204 15.1404 16.0471 14.9779 16.7700 14.0115 Med. Householdlncome 35.8001 33.1040 36.3837 34.8543 35.6245 35.3025 Pe’cemag" °fCh"d'e"‘" 16.5882 15.6422 12.5887 17.3796 13.0240 10.5404 Poverty Percentage of Children Black 2.8713 4.9998 3.4797 6.7075 1.8736 2.3503 Pirceniageomh‘m'e“ 28.9470 24.3305 19.1421 26.8825 31.8585 34.0138 Hispamc Herfindahl Index forRace 60.0797 56.1949 56.4036 59.4534 58.5670 51.6981 gi'fi‘mge OfAduhw'fl‘” 27.0420 23.9646 17.4619 24.5834 21.0595 23.3758 Pircemage “Ad“"w‘th 24.9958 25.5062 24.9778 25.4451 21.6060 28.4146 Hrgh School PercentagedAduhw‘m 29.9629 33.0880 36.8122 32.7108 34.1032 34.1096 Some College Percentage °fAd“"""."h 17.9994 17.4412 20.7481 17.2607 23.2313 14.1000 Bachelor Degree or H1 gher Average Years of Schooling 13.4088 13.4686 13.8065 13.4440 13.8654 13.2944 He'fimIah'me" f“ 31.5873 29.4507 28.2123 28.3918 27.2748 27.3166 Educat1on MEAP Math Score 4th Grade 618.8822 615.2763 611.5000 614.1600 618.6500 616.9000 Graduation Rate 1.4072 2.3918 1.6143 3.4500 3.6000 1.9333 TotalExpenditurePerStudent 18.0109 42.8215 37.5880 33.2919 147.0195 37.8225 Average Special Educational Expenditure PerSmdem 0.0989 0.1128 0.0993 0.0950 0.1080 0.1164 Pupil-Teacher Ratio 22.9183 23.4600 24.8571 25.4125 23.3500 23.7000 Average Teacher Salary 25.1110 24.8379 24.5185 26.1930 23.9448 25.0770 K-12 EnrollmentDensity 81.5364 87.7917 40.9671 67.3475 146.1783 57.4615 NumberofPrivate Schools 2.2568 5.5631 4.6667 4.7500 26.0000 45.0000 Total K-12 Enrollment 3.6456 8.9111 7.0964 6.9376 21.1140 27.6347 Gr. Rate ofK-12 Enrollment 1.9272 2.0919 3.2202 6.0345 1.7747 3.3940 Percen‘agCOfpub'” SChO‘” 13.2095 20.2143 27.8592 18.5183 0.5814 6.2500 located in City 14 Table 3 (cont’d) Number of Charter Schools 6 1 1 12 14 34 Number of Observations 2 1 l 1 1 Med. House Value 81.4525 87.0370 172.1070 183.2150 226.4900 Per Capita Income 11.5705 10.2930 14.6750 16.1970 15.3170 Med. Household Income 26.4850 22.7000 27.0900 3 1.9910 30.7950 Percentage of Children in Poverty 29.9362 32.0099 29.7194 20.9674 27.3885 Percentage of Children Black 4.9249 2.7295 51.2762 14.0586 13.6627 Percentage of Children Hispanic 39.1633 10.6700 17.7937 28.4801 59.1756 Herfindahl Index for Race 38.8973 76.2095 34.1082 29.1420 41.0275 Percentage of Adult with 12 Grade 31.3894 18.9516 25.4587 17.0489 35.6124 gzgflmge 0f Ad“ With High 24.8657 20.3629 20.9801 21.4979 19.6746 2:15:23“ °f Ad“" With some 29.0823 39.7177 27.9328 35.0387 25.0559 5881;621:1323?“ With BaChe'm 14.6626 20.9677 25.6284 26.4145 19.6571 Average Years of Schooling 13.1475 13.8629 13.8418 14.1152 13.3244 Herfindahl Index for Education 26.8309 27.9096 25.2537 26.7826 26.6953 MEAP Math Score 4th Grade 614.1000 629.9000 594.0000 616.1000 601.3000 Graduation Rate 5.8500 0.0000 8.8000 4.4000 13.2000 Total Expenditure Per Student 158.5740 2.5060 231.5000 571.2540 3756.8060 nggfieitfifeeg‘ 3:118:20“! 0.1160 0.1968 0.1056 0.1153 0.1081 Pupil-Teacher Ratio 24.7500 16.2000 22.6000 23.2000 24.5000 Average Teacher Salary 25.4180 23.8540 27.4040 24.8810 28.7040 K-12 Enrollment Density 203.8404 0.6787 350.9178 243.4163 430.8289 Number of Private Schools 16.5000 1.0000 54.0000 94.0000 593.0000 Total K-12 Enrollment 38.8115 0.3760 51.2340 125.1160 639.7810 Gr. Rate of K-12 Enrollment 1.4416 8.0251 0.4031 1.6966 1.2283 Percentage 0f ”"1“ SChO‘” '“ated 36.4706 0.0000 94.4444 100.0000 79.6825 in City 15 The empirical analysis involves regressing the number of charter schools in each district on the characteristics of the schools and students in those same districts. Therefore, the dependent variable occurs in non-negative integer amounts and OLS is inconsistent. One of the methods created to deal with such issues is Poisson regression, developed by Hausman, Hall and Girliches (1984) and Cameron and Trivedi (1986). Poisson regressions have been used also by Papke (1991) in the context of manufacturing firm start-up and by Downes and Greenstein (1996) in the context of private school start- ups in California. Two of the potential weaknesses of this approach are: 1) violation of the independence assumption; and 2) "overdispersion" in the data. We use the Huber- White robust standard errors to correct for dispersion. [See Huber (1967), White (1982).] There are two potential simultaneity problems in this framework. Charter schools, private schools, and public schools of choice are substitutes for each other. Entry of charter schools in a district is determined simultaneously with entry of private schools and/or public schools of choice within the same district. Moreover, public schools may respond to charter school entry by changing their behavior. We deal with both these problems by regressing the number of charter schools in 1998 on school district characteristics in 1992, the year before charter school policies began.8 The second simultaneity issue stems from the fact that students can cross district boundaries to attend charter schools.9 This means that the number of charter schools in district 1' , C ,, depends not only on the characteristics of that district, X, , but also on the 8 See footnote 6 for information about specific years. 16 characteristics of neighboring districts, X], including the number of charter schools, Q. This yields CI=f(Xl’Xj’Cj) (1) District j may be a composite of information for many districts because there may be multiple districts nearby. This definition is important because it defines market size, or the geographic area over which it is possible to attract students. We start by excluding neighboring district data altogether, focusing only on home district characteristics. Next, we substitute in for Q in (1) to obtain a reduced form that is a function only of X, and X]. In later parts of the paper, we expand the market definition to include nearby districts that do not border the home district. In most cases where nearby districts are included, composite variables are created that account both for the number of students and physical distance of the border districts relative to the home district. For variables that are hypothesized to be positively (negatively) related to the number of charter schools, increasing the distance and decreasing the proportion of students in the border districts is expected to decrease (increase) the composite variable. A common econometric issue is identifying the simultaneous equations of supply and demand. The usual simple model is not appropriate in this context because the price is exogenously fixed by the government, rather than being endogenously determined by 9 Kelejian and Prucha (1998) state that “cross-sectional spatial models frequently contain a spatial lag of the dependent variable as a regressor or a disturbance term that is spatially autocorrelated. The first of these topics is discussed here. We assume there is no spatial autocorrelation in our model. markets. This yields two equations, but only one endogenous variable: the number of charter schools in a district. Therefore, we combine them into a single equation, which can be estimated consistently without additional changes to the estimation procedure. ‘0 IV. Results In this section, specific variables are introduced that relate to various aspects of horizontal and vertical product differentiation. We hypothesize specific relationships and interpret these results for both Michigan and California, which are presented below in Tables 4 through 7. There are two reasons to expect that the results will be different across the two states. Both relate to state education policy. First, California education spending on traditional public schools is significantly constrained in wealthier school district to be below actual desired levels (Fernandez and Rogerson, 1999). Michigan also limits spending in high income districts; however, the limits appear to allow wealthier districts to come closer to their desired spending levels. In addition, Michigan has recently redistributed substantial funding to low income districts, resulting in a substantially higher average spending level (Papke, 2000). '0 Consider the following structural equations: and C, = 7,h + 72v + 6;, and C, = ,Blp + 8,. The demand for charter schools Cd is a fiinction of the variation in preferences for various horizontal characteristics h, the strength of preferences for quality v, and a disturbance 8d. The supply of charter schools C, is a function the price of inputs and output, and a disturbance 8,. Again, prices do not show up on the demand side as they usually would because price is fixed at zero. Afler imposing the equilibrium condition C = C, = C,, it now appears that we have two separate equations trying to explain the same phenomenon. Therefore, we instead estimate C = 7r,h + 7r,v + mp + a. A second key policy difference is that California’s charter school policy limits chartering authority to local school districts, implying that charters cannot start without some support from the public schools. In Michigan, school districts may serve as chartering authorities, but this permission is also extended to universities and other 11 organizations outside the district in which the charter schools reside. The possible implications of these policy differences for our results are discussed below. The demand for charter schooling is related to the size of the market. We measure the size of the market by the number of children enrolled in public schools or by the number of school-age children in the school district (ages 5-17). We would expect the number of charter schools to be positively related with this measure of "market-size," other things being equal. If entry decisions by charter schools are forward looking, trends in market size might matter as well. We therefore include the growth rate of enrollment as an independent variable. Many districts have been growing at a rapid rate, especially in California. In addition, the fact that only school districts can authorize charters in California implies that they are most likely to occur in growing districts that are adding schools. Building new charter schools, instead of traditional schools, allows the district to expand while decreasing regulatory burdens. All of these hypotheses about market size are supported by the results in Table 4- 1 (Michigan) and 4-2 (California). The coefficient on the number of students is consistently positive and significant in both states. Enrollment growth is positive and significant in California, but insignificant in Michigan. This provides support for the impact of differences in state charter policy. " The vast majority of schools are authorized by universities. I9 We use various measures of income.12 Assuming education is a normal good, we might expect both median family income and median house value to be positively related with charter school entry.13 This is especially true in California where state equalization policy has constrained public school spending in high-income districts. On the other hand, low income households may have fewer opportunities to move their residences, implying a negative relationship between income and charter entry. In other words, low- income households may demand less of a normal good, but they may also be further away from their most preferred bundle. '2 Chambers (1999) calculates school district-level cost indexes using a hedonic wage model. Many variables in our regressions are denominated in dollars, however, deflating them has very little impact on the results. All reported results are not deflated. '3 The assumption that education is a normal good relates only to the vertical dimension of education characteristics. We have no theory about the relationship between income and any horizontal characteristic. 20 Table 4-1: Regression Results for Michigan Dependent Variable: Number of Charter Schools for Each School District in Michigan, 1998- 1999 (Robust standard errors in parentheses) (1) (2) (3) (4) (5) Med. Household Income -0.0329 -0.0182 -0.0248 -0.0413 -0.0276 (0.0123) ” (0.0182) (0.0182) (0.0199) " (0.0212) Percentage of Children in 0.0059 -0.0004 -0.0067 -0.0028 Poverty " (0.0253) (0.024 1L (0.0246) (00247) Average Yrs. of Schooling 1.1902 1.0257 0.9872 0.9954 0.9729 (0.1918 " (0.2398) ** (0.2455) "”" (0.2438) "”" (0.2594) ** Herf. Index for Ad. -0. 1248 -0.1233 -0.0960 -0.1084 Education -- (0.0487) ** (0.0472) " (0.0505) * (0.0503) ** Herf. Index for Race -0.0326 -0.0312 -0.0265 -0.0249 -- (0.0108) *“‘ (0.0106) " (0.0111) ” (0.0112) " MEAP Math Score for 4th -0.0431 -0.0190 -0.0149 -0.0176 -0.0161 Grade (0.0123 ” (00103)" (0.0120) @0128L (0.0125) Productive Efficiency -3.9482 -3.8725 -3.9039 -- -_ (4.5992) (5.0275) (4.8826) Graduation Rate -0.0065 -0.0026 -0.0024 -0.0024 -0.0021 (0.0044L 40.0032) (0.0030) (0.0029) (0.0029) Tot. Exp. Per Student 0.1997 0.0326 0.0886 -0.0745 0.0485 (0.0948) " (0.0899) (0.0931) (0.1295) (0.1160) Avg. Special Educational 1.5656 1.5624 Expenditure Per Student " " " (0.8082) * (0.8056) * Pupil-Teacher Ratio -0.0151 “ " " " @0363) Avg. Teacher Salary __ -- __ 0.0469 __ (0.0260) "' Expenditure minus Foundation Grant -- -- -- -- .. Number of Priv. Schools __ __ -- -- -- Total Enrollment 0.0267 0.0263 0.0274 0.0254 0.0264 (0.0010) " (0.0029) " (0.0030) "”" (0.0033) " (0.0032) ** Gr. Rate of Enrollment -0.0379 -0.0196 -0.0201 0.0202 -0.0003 (0.0608) (0.0622) (0.0632) (0.0700) (0.0750) City __ __ __ __ __ Constant -15.1547 -7.7136 -3.8374 -5.8819 -4.6103 (1.9957) ** (3.6071) *"‘ (5.4191) (5.6816) (5.7761) Note: One asterisk (") indicates significance at the 90 percent confidence level. Two asterisks (") indicates significance at the 95 percent confidence level. 21 Table 4-1 (cont’d) Dependent Variable: Number of Charter Schools for Each School District in Michigan, 1998- 1999 (Robust standard errors in parentheses) (6) (7) (3) (9) (10) Med. Household Income -0.0303 -0.0374 -0.0208 -0.023 1 -0.0134 (0.0214) (0.0213) * (0.0188) 40.0179) (0.0175) Percentage of Children in —0.0042 -0.0050 -0.0001 -0.0151 -0.0064 Poverty (0.0243) (0.0242) (0.0242) (0.0260) (0.0245) Average Yrs. of Schooling 0.9721 0.9543 1.0215 0.9105 0.7771 (0.2538 ** (0.2624) " (0.2465) ** @2430) ** (0.2552) *" Herf. Index for Ad. -0.1126 -0. 1025 -0.1183 -0.1188 -0.1150 Education (0.0509) ** (0.0519) ** (0.0471) "”" (0.0352) " (0.0340) "”" Herf. Index for Race -0.0340 -0.0244 -0.0319 -0.0265 -0.0232 (0.0108) ** (0.0102) " (0.0099) " (0.0099) " @0094 ** MEAP Math Score for 4th -0.0173 -0.0174 -0.0145 —0.0148 -0.0115 Grade (0.0122) (0.0127L (0.0120) (0.0121) (0.0121) Productive Efficiency 3.3967 -3.7854 -3.9480 -2.4928 -1.6921 (4.8807) (4.8789) (4.6431) (5.3160) (5.4030) Graduation Rate -0.0027 -0.0022 -0.0029 -0.0038 -0.0012 (0.0030) (0.002 8) (0.003 1) (0.0037) 40.0022) Tot. Exp. Per Student -0. 1275 __ -- -- -- (0.1596) Avg. Special Educational 1.5336 Expenditure Per Student -- (0.8081) * -- -- -- Pupil-Teacher Ratio -0.03 72 -0.0175 (0.0418) (0.0310) " “ " Avg. Teacher Salary 0.0526 0.0371 (0.0268) H (0.0193) * " " " Expenditure minus -- __ 0.1853 0.2440 0.3354 Foundation Grant (0.2596) (0.2502) (0.2573) Number of Priv. Schools 0.0461 "' " " “ (0.0054) H Total Enrollment 0.0273 0.0255 0.0276 0.0253 (0.0031) H (0.0033) H (0.0029) H (0.0030) H " Gr. Rate of Enrollment -0.0436 -0.0020 -0.0141 -0.0096 ~0.0157 (0.0768) (0.0772) (0.0632) (0.0662) (0.068% City __ __ __ 0.0093 0.0091 (0.0031) " (0.0033) “ Constant -3.8675 -5.2281 -3.9424 -3.9508 -4.0476 (5.4394) (5.7439) (5.3989) (5.6821) (5.7591) Note: One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks (**) indicates significance at the 95 percent confidence level. 22 Table 4-2: Regression Results for California Dependent Variable: Number of Charter Schools for Each School District in California, 1998-99 (Robust standard errors in parentheses) (1) (2) (3) (4) (5) Med. Household Income -0.0861 -0.0739 -0.0731 -0.0695 -0.0702 (0.0300) "“" (0.0212) " (0.0232) " (0.0240) " (00245)" Percentage of Children in 0.0127 0.0274 0.0329 0.0259 Poverty (0.0234) (0.0200) (0.0210) (0.0214) Average Yrs. of Schooling 0.8558 0.7799 0.9871 0.9842 0.9486 (0.2737)" (0.3307) ** (0.3707) " (0.4839) "”" (0.4117) " Herf. Index for Ad. -0.2144 -0.2137 -0.2031 -0.2159 Education (0.0698) ** (0.0646) " (0.0784) ” (0.0728) " Alternative Herf. Index for 0.0131 0.0193 0.0146 0.0196 Race (0.0082) (0.0111) * (0.0112) (0.0113) "' STAR Math Score for 4th -0.0052 -0.0083 -0.0078 -0.0071 -0.0087 Grade (0.0158) (0.0177) (0.0185) (0.0184) (0.0181) Productive Efficiency -3.3665 -2.9579 -3.1755 (1.1353) ** (3.7429) (3.4613) Dropout Rate 0.0176 -0.0026 -0.0042 0.0038 -0.0039 (0.0328) (0.0379) (0.0370) (0.0350) (0.0358) Tot. Exp. Per Student -0.0170 -0.0163 -0.0150 -0.0138 -0.0153 (0.0014) " (0.0022) ** (@025) " (0.0031) ** (0.0032) " Avg. Special Educational -1 .0158 -0.6271 Expenditure Per Student (8.3636) (7.1063) Pupil-Teacher Ratio -0.0262 (0.0671) Min. Teacher Salary -0. 1276 (0.0969) Expenditure minus Foundation Grant Number of Priv. Schools Total Enrollment 0.1076 0.1028 0.0960 0.0894 0.0976 (0.0089) " (0.0131) ** (0.0151) " (0.0182) “ (0.0190) " Gr. Rate of Enrollment 0.1276 0.1444 0.1325 0.1363 0.1297 (0.0557)” (0.0504) *"‘ (0.0486) ** (0.0473) ** (0.0482) ** City Constant -7.4269 0.4003 -0.6781 1.6724 0.8964 (7.9253) (9.4383) (8.9617) (9.7679) (9.9190) Note: One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks ("‘*) indicates significance at the 95 percent confidence level. 23 Table 4-2 (cont’d) Dependent Variable: Number of Charter Schools for Each School District in California, 1998-99 (Robust standard errors in parentheses) (6) (7) (8) (9) (10) Med. Household Income -0.0648 -0.0903 -0.0995 -0.0997 -0.0864 (0.0260) ” (0.0301) ** (0.0292) " (0.0278) ‘* (0.0301) *" Percentage of Children in 0.0277 0.0549 0.0191 0.0191 0.0330 Poverty (0.0194) (0.0176) ** (0.0195) (0.0194) (0.0191) "' Average Yrs. of Schooling 0.8936 1.4456 0.9530 0.9575 0.8956 (0.4198) "”" (0.4045) ** (0.3109) " (02931)" (0.3394) *" Herf. Index for Ad. -0. 1994 -0.2582 -0.1864 -0.1865 -0.2127 Education (0.0656) *" (0.0697) "“" (0.0565) *"' (0.0568) ** (0.0572) " Alternative Herf. Index for 0.0149 -0.0045 0.0018 0.0017 -0.0005 Race (0.0112) (0.0138) (0.0151) (0.0143) (0.0158) STAR Math Score for 4th -0.0095 0.0036 0.0100 0.0100 0.0091 Grade (0.0206) (0.0184) (0.0175) (0.0178) (0.0179) Productive Efficiency -1.7487 -6.8301 -3.6933 -3.6840 -3.3845 (1.7257) (1.8641)* (1.1975) ** (1.2445) *"‘ (1.2546) *"‘ Dropout Rate 0.0059 0.0271 -0.0703 -0.0704 -0.0105 (0.0376) (0.0446) (0.0607) (0.0602) (0.0498) Tot. Exp. Per Student -0.0146 (0.0028) ** Avg. Special Educational -8.4139 Expenditure Per Student (6.9365) Pupil-Teacher Ratio -0.0452 0.0619 (0.0671 ) (0.0644) Min. Teacher Salary -0.1329 -0. 1528 (0.0982) (0.0800) * Expenditure minus -0. 1037 -0.1044 -0.0574 Foundation Grant (0.0204) " (0.0205) ** (0.0243) ** Number of Priv. Schools 0.0237 (0.0071) *"' Total Enrollment 0.0939 0.0080 0.0357 0.0359 (0.0167) ** (0.0012) ** (0.0062) ** (0.0060) ** Gr. Rate of Enrollment 0.1316 0.1408 0.1228 0.1228 0.1278 (0.0459) *" (0.0477) ** (0.0434) ** (0.0434) *" (0.0443) ** City -0.0003 0.0032 (0.0042) (0.0049) Constant 4.33 52 -5 .0846 -9.6069 -9.6076 -8.3214 (10.7343) (10.4561) (9.1573) (9.1597) (9.3238) Note: One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks (**) indicates significance at the 95 percent confidence level. 24 We use both median household income and median property values, but the results are unaffected by this choice. We use household income and find that the coefficient is negative for both states. It is occasionally significant for Michigan, and uniformly significant for California. The negative coefficients contradict the evidence for California from Grutzik et a1 (1995) who finds a positive relationship between income and charter location. However, Grutzik excludes adult education levels, which is highly correlated with income. The magnitude of the effect for California (Table 4-2, column 7) suggests that a one standard deviation increase in median income ($7,781) decreases the expected number of charter schools by 65 percent. In Michigan, the effect magnitude is smaller. We include education of the adult population as an indicator of family preferences. Parents with higher education levels might receive greater utility from the education quality of their children, making them more eager to choose a charter school if traditional public schools perform below par. The measures we use are fractions of the population with: (1) high school degrees only, (ii) some college, and (iii) college degree. From these, we calculate a measure of average parent education level. The coefficient on this variable is consistently positive and significant in both states, which is consistent with the above hypothesis and the results of Downes and Greestein (1996). The magnitude for Michigan (Table 4-1, column 7) suggests that a one standard deviation increase in average years of schooling (0.6 years) raises the expected number of charter schools by 61 percent. There are at least three ways in which population diversity may be associated with parents’ demand for charter schools. First, diversity may imply greater dispersion of 25 preferences and student needs. Second, parents may desire schools whose students have characteristics similar to those of their own children. Third, the median voter model suggests that if any group has greater than 50 percent of the population, then this group may be able to control schools through voting. Populations with less than 50 percent of the population may, therefore, seek to open schools that more closely match their preferences. We include three measures of population diversity, based on race, income, and education of the adult population. Herfindahl indices are used both for race and education. A higher (lower) Herfindahl index implies a more (less) homogeneous population. Therefore, if diversity leads to more charter schools, then the coefficients on these variables should be negative. This hypothesis is generally supported by Tables 4-1 and 4-2, except that racial mix does not appear to be a factor in California. One reason for this may be the more restrictive charter-granting policies in California. If minority groups cannot affect school district polices, then these groups can seek charters on their own in Michigan. In California, they must work through the same school districts that have apparently already failed them. In Michigan, the magnitude of the effect suggests that a one standard deviation increase in either Herfindahl index yields a 29 percent decrease in the number of charter schools. Available data does not allow for easy calculations of a Herfindahl index for income at the school district level. As an alternative, we include a measure of lower tail of the income distribution, in addition to median household income. Controlling for median income, a larger portion of the population in poverty implies a less equal income 26 distribution. The coefficient on poverty in Tables 4-1 and 4-2 are generally positive, as expected, but they are usually insignificant. The geographic size of the district may be important due to transportation costs. The number of students per square mile, controlling for the number of schools, indicates the average distance to school, which we would expect to be negatively related to charter school entry. Similarly, the number of public schools is expected to be negatively related with charter school location, since a large number of public schools would be associated with lower transportation costs and greater horizontal differentiation, controlling for the number of students.” It turns out that these variables are consistently insignificant, therefore, we omit them from the results reported here.” However, whether the schools are in cities, versus suburbs and rural areas, is important. The coefficient on the proportion of schools located in a central city is insignificant for California, but positive and significant in Michigan, regardless of whether density is included. The intent of creating charter schools was to increase choice and competition in schooling. We expect charter schools to enter more frequently where school choice is limited. A larger number of private schools implies a larger number of substitutes to public schooling and, therefore, a higher degree of competition. We might expect then that the number of private schools (and public schools) will be negatively related with charter school entry."5 However, charter schools could also locate near private schools and provide a similar type of education without charging tuition. In this case, charter '4 It may also be the case that people prefer schools with few students. ‘5 They were also highly correlated, therefore, we did not include both in any given specification. ‘6 Cross-district schools-of-choice programs, which were described earlier, also measure choice, however, these do not have a significant impact. 27 school location might be an increasing function of the size of the private sector.'7 Our estimation results provide a test of which effect is dominant. The results in Table 4-1 and Table 4-2 indicate that more private schools are associated with more charter schools, providing support for the second hypothesis. The quality of public schools might be an important determinant of charter school entry. If public school quality is low, dissatisfied parents might be more inclined to choose the charter school alternative. Two of our measures of public school quality are measures of output: graduation rates and student test scores.18 Survey research suggests that when test scores are low, parents might consider alternatives to public education and we therefore expect these scores to be negatively related with charter school entry (F inn, 2000). The negative point estimates here support this hypothesis, but they are generally not significant. Student and family characteristics vary widely across districts. Previous research indicates that these differences have an important impact on education outcomes.l9 Therefore, test scores and drop out rates alone will not accurately indicate the contribution to education made by the schools themselves. The ideal measure of school quality (vertical differentiation) is value-added. We calculate a measure of public school efficiency using frontier regressions of educational production functions in which the '7 Unfortunately, we do not have data on private school tuition and other private school characteristics. '8 For Michigan, the student test is the 4th grade Michigan Educational Assessment Program (MEAP). For California, the student test is the 4th grade Standardized Testing and Reporting (STAR). We use the test scores for math since there is some evidence that math scores are more sensitive to school quality, whereas reading scores are more dependent on interaction with parents in the home. The results are unaffected by the choice of reading and math tests. '9 See, for example, Coleman (1966) and Harris (2000a). 28 dependent variable is 7th grade math scores.20 The estimated functions are shown in appendix C. The best any district can do is produce on the production frontier. The further the actual test score is from the production frontier, the more inefficient is the district. If markets are relatively efficient, then we would expect a negative relationship between this measure of efficiency and the number of charter schools. However, we find just the opposite. As with the coefficients on test scores, the efficiency coefficients are consistently negative and insignificant. However, the low significance levels are at least partially caused by the high correlation between test scores and this measure of efficiency.” Our data set includes many variables that measure the inputs of public school districts, including expenditure levels, student-teacher ratios, teacher salaries, and special education spending. To the extent that parents residing in a district do not pay the costs of education, we expect that fewer inputs will induce more charter schools to enter. The interpretation of two input coefficients requires additional discussion. First, controlling for class size, teacher salaries, and special education spending, higher expenditures per pupil implies more spending on other inputs, such as after-school programs and administrators.22 Second, variation in teacher salaries may reflect differences in compensating differentials across districts (e. g. crime) that are not accounted for by other included variables. 2° For Michigan, these scores are from 1993. For California, the scores are from 1998, which is the oldest available. 2' The correlation range is 07-09, depending on the frontier specification. 22 We use two measures of teacher salaries, namely average teacher salary and the contractual starting salary for a teacher with a bachelor’s degree and zero teaching experience. 29 The results for school inputs are different across the two states. The positive relationship between charters and special education spending in Michigan is especially interesting, given the survey evidence that charter schools attract a disproportionate number of students with special needs compared with public schools.23 The special education programs at traditional public schools often involve labeling kids and placing them in “pull-out” programs that separate kids from the mainstream. Also, Cullen (1999) finds that fiscal incentives lead traditional public schools to include more students in special programs. Charter schools, in contrast, have far lower funding levels and rarely offer pull-out programs. Therefore, one interpretation is that many parents prefer to keep their kids in mainstream classrooms and programs. In Michigan, the coefficient magnitude for special education expenditures suggests that a one standard deviation increase in this category ($156 per pupil) increases the expected number of charter schools by 24 percent. For teacher salaries, a one standard deviation increase ($6,079) raises the number of charter schools by 23 percent. A similar increase in class size decreases the number by 6 percent. The discussion of coefficient magnitudes above focuses on Michigan. In California, the effect magnitudes are larger for the demographic variables. For example, a one standard deviation increase in median household income is associated with an 88 percent drop in the number of charter schools. This may be due to differences in state equalization policy, as discussed earlier. The one demographic variable that has a One possible exception is teacher salaries, as indicated earlier. 30 smaller impact in California is the Herfmdahl index for race, which here implies only a 12 percent decrease in the number of charters, compared with 30 percent in Michigan. The effects of most other variables are quite similar across the two states. On the supply side, revenue will be a key factor regardless of a school’s objective function. In both states, schools receive the per pupil foundation grant for the district in which the school is located. This grant also indicates the districts' minimum total spending for public schools, as guaranteed by the state government. Without going into detail about how this is calculated, the important characteristic of the funding system is that public school districts with a low foundation grant also tend to have total spending that is exactly equal or slightly above the foundation grant. This means that charter schools will have an easier time competing with public schools in low-spending districts.24 We incorporate the revenue effect by including a variable that measures expenditures minus foundation grant, which should reveal a negative relationship with the number of charters. For California, the coefficient is negative and significant, as expected. The same coefficients for Michigan are positive and insignificant. In many ways, Detroit is an unusual school district in Michigan. It is by far the largest district in Michigan with an enrollment of about 180,000, which exceeds mean enrollment by a factor of 60! The ethnic composition of Detroit is much different from 23 Firm (2000, p.79) states that “many charter schools attract youngsters with more problems and deficits than the conventional schools to which they are compared.” Also, 20 percent of their survey respondents indicated that they chose a charter school because “my child’s special needs [were] not met at [the] previous school.” 2" The overall advantage/disadvantage is somewhat difficult to establish for two other reasons: 1) charter schools do not receive capital funds from the government; 2) the foundation grant does not account for grade level, allowing charter schools to focus on "cheaper" student populations. However, these differences should affect all districts in relatively equal ways. 31 the rest of Michigan, the poverty rate is much higher and test scores are much lower. Perhaps most importantly, a very large proportion of all charter schools is located in Detroit. In order to check to what extent our results are driven by this single observation, we re-run the regression from Table 4-1 column 7, omitting Detroit. We also run regressions omitting some other potential outliers, namely the very small school districts. . The results are shown in Table 5 and are fairly robust to these changes. 32 Table 5: Regression Results Omitting Potential Outliers for Michigan Dependent Variable: Number of Charter Schools for Each School District in Michigan, 1998- 1999 With Detroit Delete Detroit Delete 5% Delete 10% smallest Districts smallest Districts (with Detroit) (with Detroit) Number of Observations 517 516 492 466 Med. Household Income -0.03 74 -0.0447 -0.0485 —0.0493 (0.0213) "' (0.0216) " (0.0220) ** (0.0219) " Poverty Rate -0.0050 -0.0074 -0.0121 -0.0161 (0.0242) (0.0244) (0.0262) (0.0262) Average Yrs. of Schooling 0.9543 0.8418 0.9494 0.9164 (0.2624) ** (0.2511) ** (0.2642) " (0.2630) " Herf. Index for Ad. -0.1025 -0.0826 -0.1140 -0.1095 Education (0.0519) ** (0.0451) * (0.0523) " (0.0510) ** Herf. Index for Race -0.0244 -0.0186 -0.0264 -0.0280 (0.0102) “' (0.0096) * (0.0107) ** (0.0109) ** MEAP Math Score 4th -0.0174 -0.0169 -0.0111 -0.0101 Grade (0.0127) (0.0130) (0.0118) (0.0123) Production Efficiency -3.7854 -1.2361 -5.8932 -6.3623 (4.8789) (5.5450) (4.8209) (4.9279) Graduation Rate -0.0022 -0.0004 -0.0020 -0.0019 (0.0028) (0.0010) (0.0029) (0.0027) Avg. Special Educational 1.5336 1.2851 1.5302 1.4613 Expenditure Per Student (0.8081) * (0.9139) (0.8325) * (0.8321) * Pupil-Teacher Ratio -0.0175 -0.0457 -0.0237 -0.0258 (0.0310) (0.0321) (0.0340) (0.0338) Average Teacher Salary 0.0371 0.0399 0.0396 0.0350 (0.0193) * (0.0198) ** (0.0200) ** (0.0202) "' Total Enrollment 0.0255 0.0704 0.0267 0.0272 (0.0033) ** (0.0207) ** (0.0035) *"' (0.0035) ** Gr. Rate of Enrollment -0.0020 0.0108 0.0138 0.0083 (0.0772) (0.0802) (0.0826) , (0.0841) Constant -5.2281 -6.7197 -2.5142 -1.3709 (5.7439) (5.9850) (5.6140) (5.6048) Note: One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks (") indicates significance at the 95 percent confidence level. 33 Many charter schools attract students not only from the district in which they are located but also from neighboring districts. In order to account for this, we regress the number of charter schools not only on characteristics of the district in which the charter school is located, but also on characteristics of neighboring (contiguous) districts. There are two possible effects of neighboring districts: First, the parents may send their children to charter schools in other districts. If this were the only effect, then we would expect the neighboring coefficients to be of the same sign as the home district coefficients. Furthermore, if the charter schools expected most of their students to come from the home district, then the border-district coefficients should have lower magnitudes. The home district coefficients in Table 6 reveal results quite similar to those in Table 4-1. Also, unlike Downes and Greenstein (1996), we find that some characteristics of neighboring districts have a significant impact on the number of charter schools. 34 Table 6: Regression Result with Border Districts for Michigan Dependent Variable: Number of Charter Schools for Each School District in Michigan, 1998- 1999 (With Contiguous Districts and with Detroit) Home ] Contiguous Number of Observations 516 Med. Household Income -0.03 76 0.0158 (0.0279) (0.0639) Poverty Rate 0.0110 -0.0833 (0.0247) (0.0535) Average Yrs. of Schooling 1.0497 0.2305 (0.2887) ** (0.413 I) Herf. Index for Ad. Education -0.1 187 -0.1243 (004382“ (0.1224L Herf. Index for Race -0.0238 0.0409 (0.0110 ** (0.0253) MEAP Math Score 4th Grade -0.0076 -0.0914 (0.0135) (0.0375) ** Production Efficiency -1.2660 -9.3094 (5.7479) (4.8134L“ Graduation Rate -0.0032 -0.0043 (0.0034) (0.0066) Avg. Special Educational 0.3621 5.7005 Expenditure Per Student (0.8689) (1.6936) ** Pupil-Teacher Ratio -0.1105 0.4073 (0.0381) ** (0.0956) ** Average Teacher Salary 0.0157 -0.0783 (0.0217) (0.0526) Total Enrollment 0.0194 0.0088 (0.0036L" (0.0071) Gr. Rate of Enrollment -0.0985 0.3104 (0.0878) (0.1903) * Constant -3.9033 (4.9852) " Note: One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks (**) indicates significance at the 95 percent confidence level. 35 V. Conclusion This paper provides evidence about the equity and efficiency effects of charter schools by studying their location patterns. The results reinforce the conclusions of existing research that finds a significant impact of racial diversity. However, we clarify this result by including variables that measure other forms of diversity, including income and adult education levels. The effect of population diversity on the demand for charter schools may reflect differences in preferences for education programs, not just preferences for homogeneous student populations. We find mixed support for the effect that charter schools have on school efficiency. Charter schools do appear to locate in more school districts with less efficient public schools. However, they also locate in districts that should already be competitive by way of private school entry. Therefore, instead of providing competition, charters may simply shift resources to students who previously went to private schools. The results here also suggest that state policies toward charter and public schools do impact the location of charter schools. This means that state education policy at least partially determines the effects that charter schools have on equity and efficiency. Several other issues are left for future research. One is the impact that charter schools have on public school performance. Also, Table 6 here indicates that the characteristics of border districts seem to impact charter location. While this specification does not seem to alter the general role of home district characteristics, the general issue of geography and market size warrants further attention. 36 APPENDICES 37 Appendix A: Summary Statistics (Michigan) Table A: Summary Statistics (Michigan) Variable Mean Std. Dev. Min Max Med. House Value 55.1641 23.5722 19.0000 230.3750 Per Capita Income 12.5686 3.9566 6.2200 48.3400 Med. Household Income 29.3916 9.3980 9.8050 88.9180 Percentage of Children in Poverty 14.9930 9.6126 0.0000 51.7051 Percentage of Children in Black 3.6778 11.6971 0.0000 97.0390 Percentage of Children in Hispanic 2.3 795 3.2701 0.0000 35.2941 Herfindahl Index for Race 87.4753 12.4457 37.7571 100.0000 Percentage of Adult with 12 Grade 23.3867 7.5265 2.5726 51.0638 Percentage of Adult with High School 37.5373 7.1426 6.6098 60.1852 Percentage of Adult with Some College 26.5604 5.901 1 3.1915 50.7564 Percentage of Adult with Bachelor 12.5156 8.4886 0.0000 60.1718 Degree or Higher Average Years of Schooling 13.0483 0.6371 11.9362 16.1 119 Herfindahl Index for Education 30.3224 2.7340 25.3326 44.43 70 MEAP Math Score 4th Grade 43.1317 13.5106 4.3000 100.0000 Graduation Rate 88.7272 115.0292 0.0000 2570.4000 Total Expenditure Per Student 4.3633 1.1428 0.0000 14.4420 Average Special Educational 0.3286 0.1559 0.0000 0.8590 EQenditure Per Student Pupil-Teacher Ratio 20.1391 3.6000 8.0000 41.0000 Average Teacher Salary 30.9208 6.0789 0.0000 51.4430 K-12 Enrollment Density 55.3187 124.0824 0.0194 1068.5000 Number of Private Schools 1.9209 5.0483 0.0000 98.0000 Total K-12 Enrollment 3.0317 8.3631 0.0040 183.1510 Gr. Rate of K-12 Enrollment -0.0817 2.4367 -11.9489 15.0722 Percentage of Public School located in 5.5431 21.7519 0.0000 100.0000 City 38 Appendix B: Summary Statistics (California) Table B: Summary Statistics (California) Variable Mean Std. Dev. Min Max Med. House Value 160.8949 99.4099 0.0000 490.9770 Per Capita Income 15.8181 7.7811 4.0510 64.9930 Med. Household Income 35.4842 13.5953 11.4060 122.9080 Percentage of Children in Poverty 16.5164 12.6396 0.0000 76.1134 Percentage of Children in Black 3.2033 6.3613 0.0000 71.5090 Percentage of Children in Hispanic 28.4079 23.7525 0.0000 100.0000 Herfindahl Index for Race 59.5052 18.2437 25.9773 100.0000 Percentage of Adult with 12 Grade 26.5714 16.1165 2.1212 90.1883 Percentage of Adult with High School 25.0245 7.2968 0.0000 87.5000 Percentage of Adult with Some College 30.4035 7.8658 0.0000 47.8919 Percentage of Adult with Bachelor 18.0006 13.0581 0.0000 70.5273 Degree or Higher Average Years of Schooling 13.4224 0.9858 11.1992 16.6736 Herfindahl Index for Education 31.2533 6.7032 25.2537 81.8317 STAR Math Score 618.2699 19.6486 555.2000 681.9000 Drop-Out Rate 1.7616 4.2021 0.0000 68.5000 Total Expenditure Per Student 27.1975 139.5741 0.0000 3756.8060 Average Special Educational 0.2453 0.8829 0.0021 16.3793 Expenditure Per Student Pupil-Teacher Ratio 22.1008 5.3378 0.0000 60.6000 Entry Teacher Salary 25.0853 2.4229 15.9120 44.3570 K-12 Enrollment Density 81.4625 149.2684 0.0000 1450.7500 Number of Private Schools 3.4679 19.2437 0.0000 593.0000 Total K-12 Enrollment 4.8513 21.1820 0.0000 639.7810 Gr. Rate of K-12 Enrollment 2.3278 4.9000 -14.4514 67.1028 Percentage of Public School located in 14.4063 33.1666 0.0000 100.0000 City 39 Appendix C: The Educational Production Frontier Function (Michigan) Table C: The Educational Production Frontier Function (Michigan) Dependent Variable: MEAP Math Test Score in 7th, 1993 Variable MLE Estimates Per Capita Income 0.1762 (Deflated by Teacher Cost Index) (0.1126) Percentage of Children in Poverty 03925 (0.1509) ** . . 0.0219 Percentage of Children 1n Black (0.0442) . . . . 0.0015 Percentage of Chrldren 1n Hispanic (0.0040) -0.4558 Herfindahl Index for Race (0.1338) H . -0.2908 Average Years of Schooling (0.0379) 4* . . 0.2453 Puprl-Teacher Ratio (0.0384) H Total Expenditure Per Student 2.0855 (Deflated by Teacher Cost Index) (3.1521) 0.2079 Total K-12 Enrollment (00357) H . -2.1753 K-12 Enrollment Densrty (27757) Average Teacher Salary 0.0051 (Deflated by Teacher Cost Index) (0.0032) * Average Special Educational Expenditure Per 0.2974 Student (Deflated by Teacher Cost Index) (0.2445) 60.1321 Consul” (9.6782) H Note: One asterisk (*) indicates significance at the 90 percent confidence level. 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S., Grutzik, C., & Carnochan, S. (1996). “The Multiple Meanings of US Charter School Reforms: Exploring the Politics of Deregulation.” Paper presented at the British Educational Research Association Annual Conference, Lancaster, UK, 1996. White, H. (1982). "Maximum Likelihood Estimation of Misspecified Models," Econometrica, Vol. 50, 1-26. Whitty, 6., Power, 8., & Halpin, D. (1998). Devolution and Choice in Education. Wohlstetter, P., Wenning, R., Briggs, KL. (1995). “Charter Schools in the United States: The Question of Autonomy.” Educational Policy, Vol. 9, December, 331-358. Wooldridge, J.M. (1992). "Quasi Likelihood Methods for Count Data." Journal of Economics, pp. 352-406. 45 CHAPTERZ ARE URBAN DISTRICTS INEFFICIENT? I. Introduction “In a move virtually unprecedented in American education, the state of Missouri is stripping away the accreditation of all [Kansas City] schools because of poor academic performance?” “The children failed the test. There are arguments about the way in which standards are imposed, but I suppose those kinds of arguments could go on forever about any test. The fact is, it's a statewide test.” Many people believe American schools are failing. In the case of urban districts, the public perception is one of complete disaster. Chicago, Detroit, Cleveland, Baltimore, Kansas City, and Los Angeles school districts have all seen serious attempts by city or state governments to impose special controls, reforms, or outright takeover. For instance, the state of Ohio has implemented an audit program that applies only to urban districts. In Michigan, Wisconsin, Florida, and Ohio, recent proposals have sought to fund school vouchers targeted almost exclusively to school children in large urban districts like Cleveland, Milwaukee or Detroit. Such proposals are certainly not new. Local governments have often been subject to special provisions and controls, usually due to extreme financial crisis or mismanagement. What is new is that the controls are now being justified based on 25 Christian Science Monitor. 46 general performance measures — i.e. student test scores. Table 1 below provides a summary of average district test scores for Michigan along several dimensions. 47 Table 1: Average Test Score along Different Dimensions Difference Mean Urban“ Non-Urban Math Grade 11 High School Test, 1999 -1 1.3457 54.0688 65.4144 (2.6300) ** Math Grade 11 High School Test, 1998 -l4.0979 49.0750 63.1729 (2.8332) " Science Grade 11 High School Test, 1999 -12.5547 41.3844 53.9390 (2.6348) ** Science Grade 11 High School Test, 1998 -11.6276 42.7281 54.3557 (2.7693) ** Rich27 Poor Math Grade 11 High School Test, 1999 10.1151 69.7714 59.6523 (1.2176) " Math Grade 11 High School Test, 1998 8.7049 66.6510 57.9461 (1.3519) " Science Grade 11 High School Test, 1999 9.3811 57.8526 48.4715 (1.2369) *"' Science Grade 11 High School Test, 1998 8.5954 57.9337 49.3383 (1.3107) ** Nonblack28 Black Math Grade 11 High School Test, 1999 3.1358 66.2749 63.1391 (1.2900) “”" Math Grade 11 High School Test, 1998 4.2681 64.4282 60.1602 (1.3931) ** Science Grade 11 High School Test, 1999 2.9967 54.6541 51.6574 (1.2981) " Science Grade 11 High School Test, 1998 4.2988 55.7812 51.4824 (1.3516) " Note: Number in parenthesis presents standard error. Two asterisks (**) indicates significance at the 95 percent confidence level. 2" Public school districts are defined as urban districts in Table 1 when half of the public schools in this district locate in large and mid-size central cities. 27 Public school districts are defined as rich districts in Table 1 when the percentage of children in poverty in a specific school district is less than 12.88 percent. We also define rich districts when the per capita income (deflated by the teacher cost index) in a specific school district is greater than 12406 dollars. The result is similar as the first definition of rich districts. 2" Public school districts are defined as black districts in Table 1 when the percentage of children in a specific school district is greater than 0.348 percent. 48 In Table 1, the difference between rich and poor districts is about 8~10 percentage points”, the difference between non-black and black districts is about 3~4 percentage points, and finally the difference between urban districts and non-urban districts is about 11~14 percentage points. Those differences are statistically significant. The distribution of scores in Table 1 comes as little surprise. The relatively low level of scores in urban districts is well known. What appears to be unknown, however, is the degree to which this is caused by low school inputs (e.g. large classes), student characteristics, or low efficiency of teachers and/or administrators. Existing research provides little, if any, evidence, even though the distinction is fundamental to evaluating and reforming schools. If the distribution of student ability or background is not equal across schools, as appears to be the case, then test scores should vary even if school perfonnance/efficiency is identical in every school. If different schooling outcomes are caused by differential school inputs, changing the amount of school inputs might be the desired policy. In neither case is institutional reform such as a state take over called for. The above discussion implies a need for some type of “value-added” measure of school performance that indicates the contribution of the school to each child’s learning. Ideally, this would involve students taking comparable tests on the first and last days of class. However, few districts actually collect such data. Another option is using student demographic data to form a proxy for student ability, and using funding levels to control for the other resources that schools have to work with. The objective is to determine how close districts are to being efficient — i.e. how close they are to the production frontier. 29 The MEAP and HSP results are reported in percentage of meeting some requirements. See Section III. Data and Model for detailed description. 49 There are at least three ways to implement the above approach. The first is to regress test scores on student characteristics and funding levels, using the error terms as measures of productive efficiency. However, this approach is inconsistent with economic theory because this allows schools to be above the production frontier. Two general approaches to fixing this problem are: data envelopment analysis and frontier regression. The former uses mathematical optimization to find the frontier. Frontier regression, as the name suggests, relies on statistical estimation of the same function. This paper uses frontier regression to estimate the productive efficiency of schools using data on Michigan school districts. The methodology is described in Section II. Estimation results are presented in Section III, yielding a measure of efficiency for each district. Besides, Section III also includes comparisons of these efficiency measures across district types. While comparisons are possible on various dimensions, the primary issue is whether large urban districts, such as Detroit, are indeed less efficient than other school districts and, therefore, whether governments are justified in targeting those districts with special controls/institutional reform to improve school performance. 11. Methodology The production frontier methodology has been developed fairly recently. Its application is increasingly widespread in many different fields, such as air force maintenance units [Charnes, Clark Cooper, and Golany (1985), Bowlin (1987)], education [McCarty and Yaisawamg (1990, 1992), Ray (1991), Wyckoff and Lavigne (1991)], national parks [Rhodes (1986)], employment offices [Cavin and Stafford (1985)], 50 and health clinics [Huang and McLaughlin (1989), Johnson and Lahiri (1992)]. The first empirical estimation of production functions begins with the papers of Cobb and Douglas (1928). However, it was largely used to study the functional distribution of income between capital and labor at the macroeconomic level. The production frontier model in disaggregated level hasn’t drawn much empirical attention until recent decades. The analysis of productive efficiency is a branch of the production frontier model because deviations from a production frontier have a natural interpretation as a measure of the efficiency with which economic units pursue their technical or behavioral objectives. Greene (1993) has a short definition for “productive efficient” that producers will be characterized as efficient if they have produced as much as possible with the inputs they have actually employed or they have produced that output at minimum inputs. Lovell (1993) defined the efficiency of a production unit as a comparison between observed and optimal values of its output and input. Koopmans (1951) provides a formal definition of technical efficiency. A producer is technically efficient if an increase in any output requires reduction in at least one other output or an increase in at least one input, and if a reduction in any input requires an increase in at least one other input or a reduction in at least one output. Thus a technically inefficient producer could produce the same outputs with less of at least one input, or could use the same inputs to produce more of at least one output. Debreu (1951) and Farrell (1957) introduced a measure of technical efficiency. Their measure is defined as one minus the maximum equiproportionate reduction in all inputs that still allows continued production of given outputs. A score of unity indicates 51 technical efficiency because no equiproportionate input reduction is feasible, and a score less than unity indicates the severity of technical inefficiency. There are two competing paradigms on how to construct the frontier efficiency model. One uses mathematical programming techniques, the other employs econometric techniques. The mathematical programming techniques is also called “Data Envelopment Analysis” (DEA), which is a body of techniques for analyzing production, cost, revenue, and profit data without parameterizing the technology. By wrapping a hull around the observed data, we can calculate the distance of each observed producer to that frontier. Presumably, the larger is the sample, the more precisely this information will be revealed. The major advantage of “Data Envelopment Analysis” approach is that no explicit functional form need be imposed on the data. However, since it lumps noise and inefficiency together, the calculated frontier may be warped if the data are contaminated by statistical noise. The econometric approach can handle statistical noise, but it imposes an explicit, and possibly overly restrictive, functional form for technology. This kind of parametric approach is likely to confound the effects of misspecification of functional form (of both technology and inefficiency) with inefficiency estimation. However, the more structure we impose on a model the better our estimates — provided the structure we impose is correct. This is a trade-off between structure and flexibility. For the econometric approach, let us construct a single production equation cross- sectional model to illustrate the basic concepts. Suppose producers use inputs x e R f to produce scalar output y e R, with technology y, =f(x.;fl)€Xp{V. +u.}- (2-1) 52 The econometric version of the Debreu-Farrell output-oriented technical efficiency (TE) measure is written TE, 2 y. [f(xr ;fl)eXP{V. }l = exp {u,} , (2.2) where [3 is a vector of technology parameters to be estimated and i =1, ..., I indexes producers. The random disturbance term v, is intended to capture the effects of statistical noise and is assumed to be independently and identically distributed as N (0,0',2 ) . The disturbance term u, is assumed to be distributed independently of v, and to satisfy u, S 0. Early studies adopted the deterministic frontier model, that is, assume v, = 0. Then the frontier becomes f (x,; )6). The residual is also adjusted to make sure that 0 < TE, 31. Winsten (1957) proposed corrected ordinary least squares (COLS), which corrects the downward bias in the estimated OLS intercept by shifting it up until all corrected residuals are nonpositive and at least one is zero. Richmond (1974) introduced modified ordinary least squares (MOLS), which makes an assumption about the functional form of the nonpositive efficiency component u,. The most popular assumption is half normal and exponential. Two-parameter distributions, including the truncated normal and the gamma distribution, are also proposed by Stevenson (1980) and Greene (1980), respectively. Finally, MLE is an implemented method that simultaneously estimates all the technology parameters and the parameters of the distribution of u,. 53 Recent econometric approaches usually select the stochastic frontier model because it allows for statistical noise resulting from events outside the firrn’s control, such as luck and weather. Employing a stochastic frontier can also be seen as allowing for some types of specification error and for omitted variables uncorrelated with the included regressors. In equation (2.1), the stochastic production frontier is f (x, ; ,6) exp{v,} and the nonpositive error component u, represents technical inefficiency. The degree of technical efficiency of a producer is given by the ratio of observed to maximum feasible output, where maximum feasible output is given by the stochastic production frontier. To calculate TE in equation (2.2), we need to estimate equation (2.1). Moreover, we need to decompose the residuals into separate estimates of noise and technical inefficiency, which is a difficult task. COLS is no longer a feasible technique. MOLS and MLE proceed roughly as in the deterministic frontier strategy, however, the resulting residuals contain both noise and inefficiency, and they adjusts the OLS intercept by minus the mean of u, , which is extracted from the moments of the OLS residuals. The distribution of the compound error term a, = v, + u, has been derived by Weinstein (1964) and is discussed in Aigner, Lovell, and Schmidt (1977). Jondrow, Lovell, Materov, and Schmidt (1982) suggested a technique to decompose the noise term and inefficiency term. For half-normally distributed inefficiency term, the log-likelihood function for the model is 0' 20' Log(a,,6,0', )1) = -—Nan' - constant + Z[ln (D[— 8’1 J — 1(5) J, (2.3) 54 and the explicit form of the estimated inefficiency component u, is Elu. 14.1 =[ “12] z.+ ¢—’—(z ) (2.4) 1+ ,1 (z ) 2 2 2 '— 8,1 . . where /1 = a", /0', , a = a", + 0"“ , z, = , ¢(-) rs the densrty of the standard normal 0' distribution, and (,u0 -f-'-/I-)] 9 0' (2.7) and the explicit form of the inefficient term u, is similar with the equation (2.4), however, replace 2,. with z, - ,u". The above three approaches are employed in our model to estimate efficiency for public school production in Michigan. III. Result Our analysis is mainly based on the Michigan public school students’ academic achievement on mathematics and science, which is measured by MEAP (Michigan Educational Assessment Program) satisfaction percentage. A cross-sectional data set of 511 public school districts in Michigan is used in our estimation”. Selected data statistics are summarized in Table 2. To investigate the relationship between the student’s performance, the school inputs and the characteristic of the specific public school district, we employ the following linear stochastic frontier model to estimate the efficiency level for individual public school district. MEAPHSTScore=a+flX,+yZ,+(v,+u,). (3.1) 3° There are 555 public school districts in Michigan, however, 44 public school districts are removed from our dataset because of missing data. These 44 public school districts were listed in Appendix A. 56 The educational achievement is measured by the MEAP (Michigan Educational Assessment Program) and HST31 (High School Test) results on Mathematics and Science for the public school students in Michigan. MEAP tested students of 4th and 7th grade in Mathematics, and the result is reported in percentage of students achieving a satisfactory performance. MEAP also tested students of 5th and 8th grade in Science, and the result is reported in percentage of satisfaction. 3' The result of HST for 11th grade in both Mathematics and Science is reported in percentage of students achieving level 1 or 2, which was adopted begins from 1998 academic year, replacing the original MEAP test for 10th graders. Level 1 implies that students exceed Michigan standard, and level 2 implies that students meet Michigan standard. We sum up the percentage of level 1 and 2 to construct a comparable measure to the original MEAP result for 10th grade. 57 Table 2: Data Statistics Summary Observation: 511 public school districts in Michigan Variable Mean Std. Dev. Min Max Math Grade 11 High School Test, 199932 64.7039 14.6509 0.0000 100.1000 Math Grade 11 High School Test, 199810 62.2900 15.8744 0.0000 93.8000 Science Grade 11 High School Test, 1999'0 53.1528 14.7343 2.9000 96.9000 Science Grade 11 High School Test, 1998'° 53.6276 15.4124 0.0000 88.7000 Math Grade 4 MEAP result, 199210 43.0955 12.8369 4.3000 89.0000 Science Grade 5 MEAP result, 1993'° 75.3025 11.0131 25.6000 100.0000 Per Capita Income33 12.9272 3.2200 6.3981 41.1796 Percentage of Children in Poverty 14.7225 9.2616 0.8441 51.7051 Percentage of Children in Black 3.9806 12.1739 0.0000 97.0390 Percentage of Children in Hispanic 2.4143 2.9180 0.0000 26.5808 Racial Herf. Index 87.0414 12.4616 37.7571 100.0000 Average Schooling Years 13.0717 0.6385 12.0772 16.1119 Educational Herf. Index 30.1435 2.4663 25 .3326 44.4370 Enrollment Density, 1998" 53.9974 101.9657 0.1466 758.5000 Average Enrollment Density, 1990-199812 55.6475 110.7128 0.1405 868.1875 K-12 Enrollment, 199835 3.2188 8.3143 0.0930 174.7300 Average K-12 Enrollment, 1990-199813 3.2061 8.4432 0.0878 177.9384 Total Expenditure, 199810 6.3248 1.0456 4.4017 17.0296 Average Total Expenditure, 1990-1998'° 5.3944 0.8739 3.2534 11.2415 Average Teacher Salary, 199810 46.1317 4.8170 32.6905 62.0232 Average Teacher Salary, 1990-1998'o 38.9330 3.6639 28.3104 50.6924 Specilgl Educational Expenditure per student, 0.4193 0.1534 0.0000 1.0793 Aiii'age Special Educational Expenditure per 0.3859 0.1391 0.0000 0.8993 student, 1990-1998'° Pupil-Teacher Ratio, 1998:"5 21.1898 2.4926 10.0000 29.0000 Average Pupil-Teacher Ratio, 1990-1998“ 21.3116 2.4068 9.7500 28.3750 3’ 1n percentage points. 33 In thousand dollars, and deflated by Teacher Cost Index. 3‘ In persons per square kilometers. 35 In thousand persons. 3" In number of students per teacher. 58 Here, X, is a vector of characteristics of public school districts, including per capita income, percentage of children in poverty, percentage of children in Black, percentage of children in Hispanic, educational Herfindahl index”, average schooling years, K-12 enrollment, and student density,...etc38. In equation (3.1), Z, is a vector of school input variables, includes pupil-teacher ratio, total expenditure, average teacher salary, and special educational expenditure per pupil..etc. The random disturbance term is v, , which captures the effects of statistical noise, is assumed to be independently and identically distributed as N (0, of). The other disturbance term u, is assumed to be distributed independently of v, and to satisfy u, _<_ 0. Three different functional specifications are used. The output variable is MEAP satisfaction percentage for all models, however, we change the characteristic variables and school input variables for different models. In Model 1, the characteristics variables includes per capita income, percentage of children in poverty, percentage of children which are Black, percentage of children which are Hispanic, educational Herfindahl index, average schooling years, K-12 enrollment, and student density. The school input variables includes pupil-teacher ratio, total expenditure, average teacher salary, and special educational expenditure per pupil. In Model 2, we use racial Herfindahl index instead of percentage of children in Black and percentage of children in Hispanic in the 37 The educational Herfindahl index is constituted by summing up the square term of the percentage of adult educational attainment including 12 grade, high school, some college, and bachelor or higher. When the adult educational attainment is homogenous, say all are with high school education, the value of index is at its maximum, which equals 1. The smaller the value of educational Herfindahl index, the more heterogenous the adult educational attainment is in that school district. 33 Per capita income, average teacher salary, total expenditure, and special educational expenditure per pupil are deflated by teaching cost index (TCI). 59 characteristic variables. In Model 3, we add square term of school input variables based on Model 2’s specification. Ordinary least squares estimates of the education production of Model 1, 2, and 3 appear in Table 3. Greene (1993) suggested that although the OLS coefficients themselves are of somewhat limited usefulness in the frontier model, it is worthwhile to note how different assumptions and estimators sometimes only produce minor variation from the OLS estimates. We will also show MLE estimates for different specification for the efficiency term later for comparison. The consistency of the OLS estimates does not require the normal distribution of the compound error term, instead, the only requirement is the zero mean of the error term. Therefore, we can always get the consistent OLS estimates by subtracting the mean of compound error term from both of the constant term and the compound error term. Since the OLS estimates are consistent here, exploring the impacts of each input variable on the educational performance for the public school districts in Table 3 is a good starting point. The MLE results reported in Appendix B are remarkably similar to the OLS results for all those specifications. Table 3 shows that the lower the socioeconomic status (higher percentage of children in poverty, higher percentage of children who are minority, and fewer years of adult’s schooling) and the poorer the characteristics of school districts (higher enrollment density), the lower the HST test result is. 60 Table 3: OLS Estimates for Different Models Observation: 511 public school districts in Michigan Dependent Variable: Math Grade 11 High School Test, 1999 Model 1 Model 2 Model 3 Per Capita Income, 1989 -0. 1659 -0.2769 -0.2790 (0.3003) (0.3067) (0.3017) Percentage of Children in Poverty, 1989 -0.1889" -0.3397** -0.2483"‘* (0.0923) (0.0876) (0.0919) Percentage of Children Black, 1989 -0.3395** -- -- (0.0600) -- -- Percentage of Children Hispanic, 1989 -0.3649** -- -- (0.1724) -- -- Racial Herf. Index, 1989 -- 0.2021" 0.2006" -- (0.0526) (0.0520) Educational Herf. Index, 1989 -0.2552 -0.1994 -0.2220 (0.2191) (0.2236) (0.2204) Avg. Schooling Years, 1989 8.5937" 8.7564" 9.3384” (1.3783) (1.4343) (1.4253) K-12 Enrollment, 1998 0.0581 -0.0224 0.0150 (0.0645) (0.0641) (0.0636) Enrollment Density, 1998 -0.0114*" -0.0155** -0.0176** (0.0055) (0.0055) (0.0055) Pupil-Teacher Ratio, 1998 4.0099" 4.3681" -9.7294** (0.3246) (0.3198) (2.2359) Pupil-Teacher ratio (Square), 1998 -- -- 0.1908" -- -- (0.0516) Total Expenditure, 1998 -1.0312 -1.5417* -3.7346 (0.8337) (0.841(3) (2.4016) Total Expenditure (Square), 1998 -- -- 0.0225 -- -- (0.1271) Average Teacher Salary, 1998 0.6634” 0.7850" 5.4527" (0.1337) (0.1330) (1.4488) Average Teacher Salary (Square), 1998 -- -- -0.0484" -- -- (0.0153) Special Educational Expenditure, 1998 -0.8303 -0.2903 5.1694 (3.5165) (3.5926) (12.3680) Special Educational Expenditure -- -- -4.9503 (Square), 1998 -- -- (12.5879) Constant -34.6820* 49.2028" -66.6397 (20.2290) (22.5234) (43.0470) Note: Number in parenthesis presents standard error. One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks (**) indicates significance at the 95 percent confidence level. 61 In addition to regressing Math High School Test in 1999 on the characteristic and school input variables in 1998 (Type 1 showed in Table 3), there are four more alternative specifications for each model. We regress Math High School Test in 1999 on the average characteristic and school input variables from 1990 to 1998. We also regress Math High School Test in 1998 on the characteristic and school input variables in 1998. Moreover, we regress Math High School Test in 1998 on the average characteristic and school input variables from 1990 to 1998. Finally, we regress Math High School Test in 1999 on the Math MEAP in which grade results in 1992, and average characteristic and school input variables from 1992 to 1998”. Table 4 summarizes all of five types of regressions as follows: Table 4: Summary of Five Types of Regressions for Model 1, 2, and 3 -329..- _ ‘ 1 2.-. 3 -,4 5 , ,. . -- . __ .‘ _ ,_ PsesndsatVariablc-_. _ Math/ Science Grade 11 High School Test, 1999 x x x Math / Science Grade 11 High School Test, 1998 x x I M F ' Explanatory Variables Socioeconomic Status of the Students, 1989 x x x x x Characteristics of Public School Districts, 1998 f x x x Characteristics of Public School Districts, Average x x 1991-98 ' Schools’ Inputs, 1998 E x x x Schools’ Inputs, Average 1991-98 1‘ x x MEAP Math 4th Grade, 1992 / Science 5th Grade, x 1993 % ’9 This is analogous to the value-added approach in Fox and Taylor (1991) and Grosskopf, Hayes, and Weber (1991). 62 We found the regression results are robust across all these different specifications within the same model. Table 5 presents method of moments estimators for the parameters of our stochastic frontier models. The basis for the calculations appears in equation (2.3) — (2.7). All the analysis in Table 5 is carried out using the LIMDEP (Greene, 1991) computer program. However, it did not automatically calculate the efficiency measure defined in equation (2.2), which limits the value of efficiency between 0 and 1. The estimated outcomes by LIMDEP includes observed Y, predicted Y, residual (efficiency term u,), xflfl , and y — xué . In order to calculate the measure of efficiency defined in equation (2.2), we adopt Coelli’s (1996) definition as follows: EFF, = E(y,.' Iu,,x,)/E(y: lu, = 0,x,) = (x,,3+t?,)/x,,é. (3.2) Comparing equation (3.2) to equation (2.2) TE z y, z f(x';fl)exP{v’ +u') =exp{u} (2 2) ' [I’m/”6mm [f(x,;,6)eXP{V.}] ' ’ - we obtain TE, = y, = f(x,;,6)exp(u,) =exp{fi,}, (2.2’) f (mm f(x.;[3) where the numerator in equation (3.2) presents the sum of the predicted HST result and the efficiency residual term (negative in our model), which is similar to the numerator in equation (22’), except that equation (2.2’) adopts a Cobb-Douglas production form. Remember y, = f (x,; ,B)exp{v, +u,), and predicted value of y, becomes 63 j», = f (x, ; fig) exp{zi,). The denominator presents the predicted test score excluding the efficiency residual term, which is the optimal test score when no inefficiency occurred, and which is similar to the denominator in equation (2.2’). Table 5 shows that the estimated average efficiency are similar across different specification of the functional form for efficiency term (half-normal, truncated-normal, and exponential). 64 Table 5: Estimated Efficiency Distribution for Different Models Model 1 1 Model 2 1 Model 3 Half-Normal x 1.0140 1.0345 1.0154 0 12.9528 13.2754 12.9215 E(u,) 7.3173 7.5740 7.3107 E(TE,.) 0.8953 0.8925 0.8956 Truncated-Normal40 u/ 0;, 0.0218 0.0170 0.009] X 1.1161 1.1366 1.0869 0 13.5568 13.7876 13.3317 E(u,.) 7.9558 8.1465 7.7472 E(TE,) 0.8873 0.8852 0.8901 Exponential 0 0.1833 0.1757 0.1804 0', 8.9961 9.1237 8.9572 E(u,) 5.4544 5.6928 5.5424 E(TE,) 0.9196 0.9166 0.9185 ‘0 Greene (1993) claimed that although truncated-nonnal benefits by relaxation of a possibly erroneous restriction (,u =0), the cost appears to be that the log-likelihood is relatively flat in the dimension of p.. Therefore, estimation of a nonzero ,1: often inflates the standard errors of the other parameters considerably, and quite frequently impedes or prevents convergence. We also encounter the same problem when estimating the individual value of efficiency, which is assumed as truncated-normally distributed. The results produced by LIMDEP for truncated normal model routinely denied convergence and, as often as not, produced nonsense estimates according to the warning message showed by program. Therefore, we also run the same estimation by using the FRONTIER 4.1 (Coelli, 1995) computer software. It did not produce any error message for the truncated normal model. Besides, we found that the values of the individual efficiencies are the same in the result carried out by LIMDEP and FRONT 4.1 (accurate to 4 decimal points). Hence we still report the truncated normal result for our model. 65 There are totally 45 regressions for Mathematics and Science, respectively“. However, only 18 regression results for Science are reported since OLS residuals do not pass the skewness check. This implies the model is probably not well specified or the data are inconsistent with the model. Average efficiency is calculated by summing up all the efficiency calculated from each of the regressions, then divided by total number of regressions estimated. We rank all the public school districts from least efficient to most efficient according to the value of average efficiency, and report the 20 least efficient public school districts in Table 6. Table 6A is for Mathematics, and Table 6B is for Science. Besides, Hanushek (1986) discussed the drawbacks of test scores as a single measure of educational output and claimed that the perceived importance of schooling is to affect the ability of students to perform in and cope with society after they leave school. Therefore, the percentage of continuation of schooling (graduation rate) would be a better measure for school performance in some extent. We also use the graduation rate as the dependent variable in our production model for comparison, and the estimated result for efficiency measure is reported in Table 6C. Finally, the 20 most efficient school districts are also reported in Appendix C. “ There are 5 types of regressions for each of three models, moreover, each of them has three alternative functional form of efficiency term 66 Table 6A: 20 Least Efficient Public School Districts for Math Avg. Relative District Percent of Schl. Relative Math SChOOI District Name Efi‘iciency"2 Size“3 In City Test Score“ Engadine Consolidated Schs 0.4150 0.1053 0.00 0.0000 Burr Oak Comm School Dist 0.5192 0.1084 0.00 0.2922 Waldron Area Schools 0.5501 0.1345 0.00 0.7192 City Of Muskegon Heights Sd 0.5657 0.7695 0.00 0.1445 Highland Park City Schools 0.6039 1.1274 0.00 0.2312 Benton Harbor Area Schools 0.6149 1.8050 100.00 0.1589 Fulton Schools 0.6217 0.3007 0.00 0.3211 Buena Vista School District 0.6273 0.5120 100.00 0.1445 River Rouge City Schools 0.6935 0.7910 0.00 0.2504 Deerfield Public Schools 0.6951 0.1277 0.00 0.3211 Arenac Eastern School Dist 0.6997 0.1488 0.00 0.5940 Dearbom Hgts Sch Dist No. 7 0.7065 0.7528 0.00 0.2569 Baldwin Community Schools 0.7092 0.2461 0.00 0.3773 Ecorse Public School Dist 0.7128 0.3902 0.00 0.4495 Britton Macon Area Sch Dist 0.7371 0.1516 0.00 0.5153 Oak Park City School Dist 0.7446 1.1231 0.00 0.4013 Pontiac City School District 0.7569 3.9676 93.55 0.3757 Memphis Community Schools 0.7633 0.3116 0.00 1.0708 Springport Public Schools 0.7656 0.3389 0.00 0.4913 Westwood Community Schools 0.7659 0.6822 0.00 0.4880 ‘2 The mean of average efficiency for math test is 0.9001, and with 10% percentile of 0.8099, 25% percentile of 0.8627. ‘3 Numbers are reported as K-12 enrollment in 1998 of each district divided by average K-12 enrollment in 1998. ‘4 Numbers are reported as HST Math test score in 1998 of each district divided by average HST Math test score in 1998. 67 Table 6B: 20 Least Efficient Public School Districts for Science School District Name Efl'léi‘gcy” RelatgiggsMCt PercitrllthfySchl. Relagsiyg 3:11:3C6 Highland Park City Schools 0.0000 1.1274 0.00 0.0000 Burr Oak Comm School Dist 0.3099 0.1084 0.00 0.0000 Engadine Consolidated Schs 0.3100 0.1053 0.00 0.0000 City Of Muskegon Heights Sd 0.4163 0.7695 0.00 0.0839 Inkster City School District 0.4343 0.5589 0.00 0.1175 Godfrey Lee Public Sch Dist 0.4498 0.3871 0.00 0.1548 Coloma Community Schools 0.4928 0.7298 0.00 0.2667 Marenisco School District 0.4937 0.0367 0.00 0.2667 Willow Run Community Schools 0.5347 1.0361 0.00 0.2387 Webberville Community Schs 0.5448 0.2426 0.00 0.3897 Fulton Schools 0.5471 0.3007 0.00 0.3729 Buena Vista School District 0.5542 0.5120 100.00 0.1883 Akron Fairgrove Schools 0.5775 0.1553 0.00 0.4084 Benton Harbor Area Schools 0.5902 1.8050 100.00 0.2200 Mason Cons School District 0.5928 0.4837 0.00 0.3767 Detroit City School District 0.6160 54.2843 94.59 0.2461 Kingsley Area School 0.6230 0.3974 0.00 0.4662 Oak Park City School Dist 0.6254 1.1231 0.00 0.2816 T ahquamenon Area Schools 0.6429 0.3821 0.00 0.4736 Dearbom City School Dist 0.6475 4.9329 96.30 0.5128 4’ The mean of average efficiency for science test is 0.8771, and with 10% percentile of 0.7462, 25% percentile of 0.8292. 4° Numbers are reported as K-12 enrollment in 1998 of each district divided by average K-l2 enrollment in 1998. ‘7 Numbers are reported as HST Science test score in 1998 of each district divided by average HST Science test score in 1998. 68 Table 6C: 20 Least Efficient Public School Districts for Graduation Rate School District Name Avg. Relative District Percent of Schl. Relative Efficrency"8 Size49 In City Graduation Rate50 Lansing Public School Dist ' 0.4569 5.9181 166.067 ‘ " ”W6 136?” Inkster City School District 0.5022 0.5589 0.00 0.4590 Galien Township School Dist 0.5930 0.1417 0.00 0.6428 Colon Community School Dist 0.6030 0.2986 0.00 0.6475 Eau Claire Public Schools 0.6348 0.2774 0.00 0.6760 Ecorse Public School Dist 0.6357 0.3902 0.00 0.6025 Mancelona Public Schools 0.6360 0.3408 0.00 0.6819 Jackson Public Schools 0.6600 2.3788 100.00 0.6736 River Rouge City Schools 0.6615 0.7910 0.00 0.6392 Fennville Public Schools 0.6784 0.5008 0.00 0.7009 River Valley School District 0.6805 0.4110 0.00 0.7507 Lakeville Comm School Dist 0.6871 0.7105 0.00 0.7353 Hale Area Schools 0.6971 0.2554 0.00 0.7566 Grand Haven City School Dist 0.7046 1.8836 0.00 0.7673 Alcona Community Schools 0.7060 0.3287 0.00 0.7732 Orlaway Area Comm School 0.7081 0.2973 0.00 0.7626 giaslievue Comm Sch Dist 0.7121 0.3203 0.00 0.7768 Huron School District 0.7181 0.6036 0.00 0.7697 Saranac Community Schools 0.7187 0.3821 0.00 0.7780 South Haven Public Schools 0.7217 0.8727 0.00 0.7448 ‘8 The mean of average efficiency for graduation rate is 0.9135, and with 10% percentile of 0.7965, 25% percentile of 0.8555. ‘9 Numbers are reported as K-12 enrollment in 1998 of each district divided by average K-12 enrollment in 1998. 5° Numbers are reported as graduation rate in 1998 of each district divided by average graduation rate in 1998. 69 Detroit is the largest urban school district in Michigan and has been the focus of much policy debate, hence it may worth our additional attention. Departing from the common perception that Detroit is in a complete disaster for education, Detroit does not show up in the list of 20 least efficient public school for HST math result. The average efficiency measure of Detroit for Mathematics is 0.7898, and with the rank of 33. For science test score, Detroit performs much worse with an average efficiency measure of 0.6160, and a rank of 16. For both the HST math and science results, Detroit’s measure of efficiency is roughly twice as large as the least efficient one. Besides, when we measure district performance by using graduation rate, Detroit even performs very well, the average efficiency measure for graduation rate is 0.9450, and with a rank of 357. Besides, from Appendix D we see that Detroit enter the list of 20 least efficient school districts for HST math result only once in total 45 regressions. However, it shows up most of time in the list of 20 least efficient school districts for HST science result (17 out of 18 regressions). Finally, Detroit show good performance in graduation rate again. It did not enter the list of 20 least efficient school districts for graduation rate, and with an average ranking of 343.74. We report the relative measure of efficiency for Detroit in Table 7. 70 Table 7: Relative Measure of Efficiency for Detroit Regression Half Normal Truncated- Exponential Normal HST Mathematics, 1998 Model 1 Type 3 0.8399 0.8385 0.8747 Type 4 0.8396 0.8349 0.8694 Model 2 Type 3 0.8222 0.8208 0.8690 Type 4 0.8243 0.8234 0.8656 Model 3 Type 3 0.8300 0.8299 0.8705 Type 4 0.8288 0.8162 0.8679 HST Science, 1998 Model 1 Type 3 0.6903 0.6994 0.7405 Type 4 0.6756 -4.8621 0.7441 Model 2 Type 3 0.7110 0.7100 0.7735 Type 4 0.7030 0.6992 0.7680 Model 3 Type 3 0.7049 0.7019 0.7660 Type 4 0.7080 0.7045 0.7706 Graduation Rate, 1998 Model 1 Type 3 1.0665 1.0668 1.0336 Type 4 1.0682 1.0688 1.0361 Model 2 Type 3 1.0714 1.0721 1.0310 Type 4 1.0720 1.0710 1.0345 Model 3 Type 3 1.0666 1.0710 1.0296 Type 4 1.0728 1.0786 1.0342 Note: Number reported as measure of efficiency divided by average measure of efficiency in each regression. 71 Roughly speaking, Detroit is relatively inefficient in the production function of schooling in our model, however, it did not perform as bad as people think. The difference between the regression result and the common knowledge maybe comes from the different measure of academic performance. Usually, people use the test score to justify whether a specific school district performs well or bad. However, as we mentioned in section I, if the characteristics of students are different, then the performance of test score may not only result from the school inputs. We examine the correlation coefficient between the test result and the efficiency measure, as well as the correlation coefficient between the graduation rate and the efficiency measure. Table 8 shows the correlation coefficient between the HST mathematics result in 1998 and the estimated efficiency is around 90 percent when we use half-normal or truncated normal model. However, the correlation coefficient decreases when an exponential model is used (up to 12 percentage points). This is also the case for HST mathematics result in 1998, and for most of the HST science result. On the other hand, we found the correlation coefficient is roughly 95 percent between the graduation rate and efficiency measure, and this highly correlated property may suggest that graduation rate is a better index for district’s academic performance then test score. 72 Table 8: Correlation Coefficients between Educational Achievement and Efficiency Efficiency Half Normal Truncated-Normal Exponential HST Mathematics, 1998 Model 1 Type 3 0.9120 * 0.9100 * 0.6908 * Type 4 0.9136 * 0.9125 * 0.8428 * Model 2 Type 3 0.9087 "‘ 0.9061 * 0.8454 * Type 4 0.9108 * 0.9075 * 0.8526 * Model 3 Type 3 0.9061 "‘ 0.9034 * 0.8438 * Type 4 0.9084 * 0.9085 * 0.8517 * HST Science, 1998 Model 1 Type 3 0.4939 * 0.5483 * 0.7398 * Type 4 0.0370 0.1352 * 0.6995 * Model 2 Type 3 0.9106 * 0.9094 * 0.8394 * Type 4 0.9195 * 0.9149 * 0.8427 * Model 3 Type 3 0.9104 * 0.9105 * 0.8366 * Type 4 0.9105 * 0.9109 * 0.8412 * Graduation Rate, 1998 Model 1 Type 3 0.9436 * 0.9425 "‘ 0.9099 * Type 4 0.9441 0.9423 * 0.9125 * Model 2 Type 3 0.9554 * 0.9541 * 0.9460 * Type 4 0.9560 * 0.9543 * 0.9207 * Model 3 Type 3 (1998) 0.9535* 0.9548 * 0.9144 * Type 4 (1998) 0.9560 * 0.9574 * 0.9202 * Note: Asterisk (*) indicates significance at the 95 percent confident level. 73 Table 9 reports the comparison of estimated efficiency in different dimensions. Except the category of city (urban district is defined as when at least half of schools are located in city), all other categories divide 511 school districts into two even parts by ordering from least to best and cutting right in half. We make the dummy variables for all categories, and run OLS regression on those dummy variables in each dimension once a time. Although the efficiency measure is estimated by assuming they are distributed half-normally, truncated normally or exponentially, the OLS estimates are still the best unbiased estimates because our sample size is large enough (511 observations). We found that urban districts always have lower estimated efficiency. The difference of estimated efficiency between urban districts and non-urban districts are significant, and with the value of 3.65 percent. Besides, the poorer district (no matter measured by per capita income or the percentage of children in poverty) tends to have lower efficiency and the difference of 2.16 percentage points is significant. The adult educational level is also an important factor of efficiency in our model. The districts with higher-educated parents are more efficiency for Mathematics. The difference of estimated efficiency is significantly large, which is 3.18 percentage points. The other factors, which caused significant difference of efficiency, are K-12 enrollment, percentage of children who are black and total expenditure. Larger districts, the districts with higher percentage of black children, and the districts with more total expenditure tend to be more inefficient, and the decreased efficiency is around 1 percentage point. 74 Table 9: Comparison of Estimated Efficiency (HST Math) Variable City K-12 Enrollment, 1998 Enrollment Density, 1998 Percentage of Children in Poverty Percentage of Children in Black Percentage of Children in Hispanic Average Schooling Years Per Capita Income, 1989 Pupil-Teacher Ratio, 1998 Total Expenditure, 1998 Estimated Efficiency Urban 0.8506 Large 0.8882 High Density 0.8845 Poor 0.8725 Black 0.8782 Hispanic 0.8861 High Education 0.8992 Poor 0.8719 Large Class 0.8850 High Exp. 0.8781 Rural _. .. . __ . 0.8855 Small 0.8784 Low Density 0.8820 Rich 0.8941 Non-Black 0.8884 Non-Hispanic 0.8805 Low Education 0.8673 Rich 0.8946 Small Class 0.8816 Low Exp. 0.8885 Difference --.tStd; Dew)--. 0.0365“ (0.0115) 0.0098“ (0.0056) 0.0025 (0.0056) 0.0216" (0.0055) 0.0101* (0.0056) 0.0056 (0.0056) 0.0318" (0.0054) 0.0227" (0.0055) 0.0034 (0.0056) 0.0103* (0.0056) Note: Number in parenthesis represents standard error. One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks (") indicates significance at the 95 percent confidence level. 75 Other than comparing the mean of efficiency measure for each categories, we can also specify the efficiency measure as the function of some explanatory variables. That is, instead of treating efficiency measure as an independent random variable, we doubt it is correlated with some of the explanatory variables. FRONT41 provides this function, and the result is reported in Table 10. In Table 10, we specify city, total expenditure, poverty rate, and K-12 enrollment may explain the efficiency measure, and we found that none of them have significant impact on efficiency measure. Moreover, the coefficients lose their significance when they simultaneously explain both test score and efficiency measure. 76 TablelO: MLE Estimates for Technical Efficiency Models for Math Test Model 1 Math Score Efficiency City 0.0432 ” (0.0520) Per Capita Income, 1989 -0.2074 (0.2955) " Percentage of Children in -0.0712 0.2841 Poverty, 1989 (0.1436) (0.2572) Percentage of Children Black, -0.3540** 1989 (0.0602) “ Percentage of Children -0.3560** Hispanic, 1989 (0.1761) “ Educational Herf. Index, -0.1499 1989 (0.2169) " Avg. Schooling Years, 1989 8.5617" (0.8745) -- K-12 Enrollment, 1998 -0.0210** -0.5284 (0.0617) (0.4998) Enrollment Density, 1998 -0.0130** (0.0055) -- Pupil-Teacher Ratio, 1998 -1.0672** (0.2801) " Total Expenditure, 1998 -0.9931 -0.2425 (0.8429) (0.7367) Average Teacher Salary, 0.6251 ** 1998 (0.1399) " Special Educational -0.8340 Expenditure, 1998 (0.9993) -- Constant -27.5924** -0.0595 (1 .0000) (1.0076) Note: Number in parenthesis represents standard error. One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks (**) indicates significance at the 95 percent confidence level. 77 IV. Conclusion In our model, we use the stochastic production frontier models to estimate efficiency for public school districts in Michigan. Three different specifications for the efficiency term including the half-normal, truncated-normal, and exponential are used. By estimating the measure of individual efficiency for HST math and science achievement, we find that urban school districts are significantly less efficient than non- urban school districts. Besides, the school districts with higher percentage of children in poverty, higher percentage of children who are black, larger enrollment (large districts), parents who are lower-educated, and larger total expenditure are less efficient. We also found that the correlation coefficient between the test score and the efficiency measure for HST math result is relatively high, however, it is not so high between the test score and some of the efficiency measures for HST science result. According to the test score, Detroit is pretty inefficient in both math and science, with rank of 6 to 10. Nevertheless, according to the measure of efficiency, although Detroit is relatively inefficient in the production of schooling, especially for HST science result, it is not the worst one. Moreover, the average measure of efficiency of Detroit is roughly twice as large as the least efficient one. In the face of the evidence presented in this paper, it seems inappropriate to single out the school district of Detroit for special institutional reform. If special institutional reforms are applied to any district they should be applied to those districts who have the lower score in our measure of efficiency. 78 APPENDICES 79 Appendix A: Public School Districts with Missing Data Table A: Public School Districts with Missing Data Relative Relative Public School District Name District Size" Publlc School Distrlct Name District Size” Autrain-Onota Public Schools 0.0149 Bloomfield Twp S D 7f 0.0075 Burt Township School Dist 0.0236 Colfax Twp Sch Dist 1f 0.0047 Saugatuck Public Schools 0.2153 Sigel Twp School District 3 0.0062 Ganges School District No.4 0.0081 Sigel Twp School District 4 0.0062 Arvon Township School Dist 0.0084 Sigel Twp School District 6 0.0050 Hagar Township School Dist 6 0.0168 Verona Twp Sch Dist No If 0.0068 Sodus Twp Sch Dist 5 0.0245 Stockbridge Comm Schools 0.5577 Mar Lee School District 0.0811 Palo Comm School District 0.0612 Beaver Island Comm Schools 0.0283 Berlin Twp School District 3 0.0056 Whitefish Schools 0.0286 Easton TWp School District 6 0.0099 Crawford Ausable Schools 0.7046 Ionia Twp School District 2 0.0093 Breitung Twp School District 0.6940 Excelsior District #1 0.01 15 Maple Valley School District 0.5052 Grant Township Schools 0.0031 Oneida Twp School District 3 0.0059 Bois Blane Pines Sch Dist 0.0016 Loucks School-Roxand #12 S/D 0.0025 Moran Township School Dist 0.0401 Littlefield Public Sch Dist 0.1491 Powell Township School Dist 0.0245 Genesee School District 0.3014 Wells Township School Dist. 0.0143 Wakefield Twp School Dist 0.1106 Holton Public Schools 0.3936 Litchfield Community Schools 0.2038 Pineview School District NA52 Elm River Twp School Dist 0.0056 Big Jackson School District 0.0118 Stanton Twp School District 0.0572 Ferry Community School Dist NA” Church School District 0.0075 Nottawa Community School 0.0522 Bloomfield #1 School District 0.0000 Bangor Twp School District 8 0.0065 " Numbers are reported as K-12 enrollment in 1998 of each district divided by average K-12 enrollment in 1998. ’2 Missing Data. 80 Appendix B: MLE Estimates for Different Models for Math Test Table B: MLE Estimates for Different Models for Math Test Observation: 511 public school districts in Michigan Output Variable: Math Grade 11 High School Test, 1999 Model 1 Model 2 Model 3 Per Capita Income, 1989 -0.l613 -0.2564 -0.2760 (0.38143 (0.3970) (0.4015) Percentage of Children in Poverty, 1989 -0. 1951 -0.3419 -0.2534 (0.0937) "”" (0.0933) ** (0.0967fi" Percentage of Children in Black, 1989 -0.3334 -- -- (0.0485) *" -- -- Percentage of Children in Hispanic, 1989 -0.3618 -- -- (0.1678 *"' -- -- Racial Herf. Index, 1989 -- 0.1911 0.1970 -- (0.0516)“ (0.0515) ** Educational Herf. Index, 1989 -0.2206 -0.1629 -0.1667 (0.2561) (0.2585) (0.2578) Avg. Schooling Years, 1989 8.2446 8.3192 8.9857 (1.7712) *"‘ (1.8434) *‘1‘ (1.9701) ** K-12 Enrollment, 1998 0.0514 -0.0305 0.0047 (0.1832) (0.2654) (0.2499) Enrollment Density, 1998 -0.01 16 -0.0154 -0.0176 (0.0067) "‘ (0.0060) ** (0.0059) ** Pupil-Teacher Ratio, 1998 -1.0593 -l.4308 -10.0091 (0.3296) " (0.3457) ** (2.2744) ** Pupil-Teacher ratio (Square), 1998 -- -- 0.1967 -- -- (0.0508) ** Total Expenditure, 1998 -0.9703 -l.5360 -3.4421 (0.7824) 40.9631) (4.6889) Total Expenditure (Square), 1998 -- -- 0.0018 -- -- (0.3255) Average Teacher Salary, 1998 0.6469 0.7695 4.9325 (0.1318) "”" (0.1330) ** (1.1341)" Average Teacher Salary (Square), 1998 -- -- -0.043O -- -- (0.0122) ** Special Educational Expenditure, 1998 -l.0690 -0.4224 1.8380 (3.5811) (3.5664) (10.6519) Special Educational Expenditure -- -- - l .4590 (Square), 1998 -- -- (10.6194) Constant -22.2901 -34.2018 -40.6176 (25.7425) (27.4516) (41.2992) Note: Number in parenthesis represents standard error. One asterisk (’) indicates significance at the 90 percent confidence level. Two asterisks (**) indicates significance at the 95 percent confidence level. 81 Appendix C: 20 Most Efficient Public School Districts Table Cl: 20 Most Efficient Public School Districts for Math N... 2.3:...” “3°“ Osceola Twp School District 0.9458 0.0935 0.00 1.2843 Croswell Lexington Comm Sd 0.9485 0.7876 0.00 1.1286 Holland City School District 0.9488 1.7634 0.00 1.2522 New Lothrop Area Public Sd 0.9502 0.2666 0.00 1.2667 Cadillac Area Public Schools 0.9502 1.2188 0.00 1.2442 Pickford Public Schools 0.9509 0.1563 0.00 1.4721 Brown City Comm School Dist 0.9518 0.3492 0.00 1.3228 Fowler Public Schools 0.9520 0.1553 0.00 1.3277 Alba Public Schools 0.9532 0.0584 0.00 1.1238 Ludington Area School Dist 0.9537 0.8572 0.00 1.4208 Rapid River Public Schools 0.9539 0.1637 0.00 1.2667 Charlevoix Public Schools 0.9542 0.4182 0.00 1.4095 Public Schools Of Calumet 0.9544 0.5412 0.00 1.3100 Dowagiac Union Schools 0.9544 0.9550 0.00 1.2795 Hamilton Community Schools 0.9545 0.6894 0.00 1.4079 Onekama Consolidated Schools 0.9546 0.1612 0.00 1.2618 N.I.C.E. Community Schools 0.9555 0.4384 0.00 1.4593 Saranac Community Schools 0.9575 0.3821 0.00 1.3453 Peck Community School Dist 0.9597 0.1793 0.00 1.4111 Zeeland Public Schools 0.9608 1.3160 0.00 1.3373 ’3 The mean of average efficiency for graduation rate is 0.9001, and with 10% percentile of 0.8099, 25% percentile of 0.8627. 5" Numbers are reported as K-12 enrollment in 1998 of each district divided by average K-12 enrollment in 1998. ’5 Numbers are reported as HST Math test score in 1998 of each district divided by average HST Math test score in 1998. 82 Table C2: 20 Most Efficient Public School Districts for Science School District Name Qggéiency“ lsllegstive District 13:22:? of Schl. figiat;:::cience Wyoming Public Schools 0.9439 1.7637 0.00 1.3836 Kaleva Norman Dickson Schs 0.9440 0.2874 0.00 1.3463 North Central Area Schools 0.9445 0.1855 0.00 1.3855 White Pine School District 0.9447 0.0510 0.00 1.4657 Rapid River Public Schools 0.9470 0.1637 0.00 1.4507 Gladwin Community Schools 0.9473 0.6633 0.00 1.3985 Saranac Community Schools 0.9477 0.3821 0.00 1.4433 Mid Peninsula School Dist. 0.9489 0.1109 0.00 1.4433 Brown City Comm School Dist 0.9490 0.3492 0.00 1.4153 Caseville Public Schools 0.9492 0.0935 0.00 1.4918 Charlevoix Public Schools 0.9496 0.4182 0.00 1.5570 Pentwater Public School Dist 0.9501 0.1156 0.00 1.5104 Public Schools Of Calumet 0.9509 0.5412 0.00 1.4582 Watersmeet Twp School Dist 0.9510 0.0596 0.00 1.5533 Mio Au Sable Schools 0.9513 0.2936 0.00 1.4414 Marlette Community Schools 0.9550 0.4499 0.00 1.5197 Onekama Consolidated Schools 0.9551 0.1612 0.00 1.5981 Pickford Public Schools 0.9581 0.1563 0.00 1.5533 Freeland Comm School Dist 0.9592 0.4595 0.00 1.6279 Bark River Harris Sch Dist 0.9600 0.1796 0.00 1.6447 ’6 The mean of average efficiency for science test is 0.8771, and with 10% percentile of 0.7462, 25% percentile of 0.8292. 57 Numbers are reported as K-12 enrollment in 1998 of each district divided by average K-12 enrollment in 1998. ’8 Numbers are reported as HST Science test score in 1998 of each district divided by average HST Science test score in 1998. 83 Table C3: 20 Most Efficient Public School Districts for Graduation Rate isiissiisiis 111......» 1:11; “5:“- W Grant Public School District 0.9763 0.7652 0.00 1.1409 Suttons Bay Public Sch Dist 0.9765 0.3330 0.00 1.1717 Glen Lake Community Sch Dist 0.9766 0.2805 0.00 1.1860 Bear Lake School District 0.9770 0.1025 0.00 1.1860 North Central Area Schools 0.9771 0.1855 0.00 1.1860 Posen Cons School District 0.9773 0.1202 0.00 1.1860 Coloma Community Schools 0.9775 0.7298 0.00 1.1634 Climax Scotts Comm Schools 0.9776 0.2203 0.00 1.1860 Atlanta Community Schools 0.9779 0.1789 0.00 1.1611 Beal City School 0.9780 0.1839 0.00 1.1860 Chippewa Valley Schools 0.9781 3.3537 0.00 1.1622 Pellston Public School Dist 0.9783 0.2308 0.00 1.1860 Sandusky Comm School Dist 0.9786 0.4579 0.00 1.1860 Adams Twp School District 0.9787 0.1656 0.00 1.1860 Godfrey Lee Public Sch Dist 0.9790 0.3871 0.00 1.1373 Akron F airgrove Schools 0.9800 0.1553 0.00 1.1860 Vanderbilt Area School 0.9801 0.1031 0.00 1.1860 Caro Community Schools 0.9802 0.7456 0.00 1.1765 Westwood Heights Sch Dist 0.9852 0.3725 100.00 1.1717 Walkerville Rural Comm Sd 0.9857 0.1274 0.00 1.1860 ’9 The mean of average efficiency for graduation rate is 0.9135, and with 10% percentile of 0.7965, 25% percentile of 0.8555. 6° Numbers are reported as K-12 enrollment in 1998 of each district divided by average K-12 enrollment in 1998. 6' Numbers are reported as graduation rate in 1998 of each district divided by average graduation rate in 1998. 84 Appendix D: Counts for Appearing in the 20 Least Public School Districts Table D: Counts for Appearing in the 20 Least Public School Districts Counts of Appearing in the 20 Least Efficient Public School Districts for School District Name Math Test Math Science Grad. rate (efficiency rank ‘2 (efficiency rank) (efficienchank) Addison Comm Schools 8 (147, 18, 67.51) 0 (241,214, 228.44) 0 (277, 253, 265.70) Akron Fairgrove Schools 0 (431,82, 287.58) 18 (16,10,13.17) 0 (509, 503,507.30) AlconaCommunity Schools 0 (368, 241,299.91) 0 (475, 443,456.33) 27 (17,13,14.96) Arenac Eastern School Dist 36 (23, 5,1380) 0 (173,145,158.50) 0 (146,129,138.33) Ashley Community Schools 9 (147, 12, 62.67) 0 (278, 232, 258.94) 0 (203,172,188.04) Atlanta Community Schools 0 (111,24, 64.24) 5 (25,17,21.78) 0 (505, 493, 499.07) Bad Axe Public Schools 13 (304,17,177.13) 0 (168,142,156.56) 0 (344,318, 334.26) Baldwin Comm Schools 40 (25,9, 14.44) 0 (46,21,29.44) 0 (401,329, 363.52) BeecherComm Sch Dist. 19 (112,10,41.18) 0 (129, 74, 85.56) 0 (150,71,113.78) Bellevue Comm Sch Dist 0 (46l,13l,279.29) 0 (431,400,419.83) 27 (18,16,16.78) Benton Harbor Area Schools 45 (13, 4, 6.84) 17 (21,11,1173) 0 (116,44, 69.44) Britton Macon Area Sd 18 (73, 8, 37.69) 0 (115, 83, 98.00) 0 (345, 305, 323.89) Buckley Comm Sch Dist- 4 (507,16,217.07) 0 (251,202, 227.50) 0 (267,217, 236.30) BuenaVista SchoolDist. 42 (25,2, 8.84) 18 (18, 8, 10.83) 0 (371,154, 236.44) BurrOak Comm Sch Dist 45 (8, 2,3.82) 18 (4,1,1.61) 0 (40, 26.33.26) Capac Comm Sch District 18 (263,16,154.11) 0 (56,45, 50.06) 0 (312, 291,300.70) Carrollton School District 16 (185,15, 72.38) 0 (177,116,151.50) 0 (415,378, 398.56) Muskegon Heights Sd 45 (12, 2, 4.91) 18 (7,1,3.56) 0 (265, 86, 147.70) Coleman Community Sd l8 (294,10,169.51) 0 (64, 52,5806) 0 (268, 249, 256.85) Coloma Community Schools 0 (348, 172, 249.96) 18 (9, 3, 7.00) 0 (508, 487, 497.37) Colon Comm School Dist 0 (393, 126, 286.33) 3 (25, 19, 22.11) 27 (4, 4, 4.00) Dearbom City School Dist 0 (223, 27, 128.98) 15 (23,14,19.17) 0 (336, 249, 293.63) Dearbom HgtsSdN0-7 18 (126,4, 56.33) 0 (30,21,25.17) 0 (229,171,190.63) Deerfield Public Schools 18 (176, 2, 67.13) 0 (60, 27, 44.50) 0 (164, 111, 141.59) Detroit City School District 1 (56,16,4l.42) 17 (21,14,1633) 0 (380, 277, 343.74) EauClaire Public Schools 17 (150,13, 56.04) 0 (163,85,109.39) 27 (7, 5, 5.85) Ecorse Public School Dist 27 (62, 5, 24.53) 0 (147,103,11739) 27 (3, 5, 6.15) Engadine Consolidated Schs 45 (2, 1, 1.62) 18 (3, 1, 1.33) 0 (279, 193, 22237) 85 Table D (cont’d) Counts of Appearing in the 20 Least Efficient Public School Districts School District Name for Math Test Math Science Grad. rate (efficiency rank) (efficiency rank) (efficiency rank) Fairvicw Area 8d 9 (88, 14, 44.33) 1 (28, 20, 24.78) 0 (436, 396,413.93) Fennville Public Sch 0 (464, 45, 193.51) 0 (68, 24,4272) 27 (12,10,10.70) Fulton Schools 45 (123,849) 18 (14,8,10.78) 0 (472, 454, 463.67) GalienTwoSd 0 (307, 54,188.04) 0 (162, 108, 134.61) 27 (3,2300) Godfrey Lee Public Sch Dist 0 (400, 174, 271.76) 18 (6, 3, 4.83) 0 (508,495, 503.41) GrandHavenCity so 0 (443,410,42453) 0 (319, 306,312.67) 27 (16, 14, 14.67) Hachrca Schools 0 (63,38,51.04) 0 (196,153,176.28) 27 (15,12,13.26) Hamtramck Public Schools 0 (300,65, 180.38) 0 (64, 49, 57.89) 5 (35, 16, 22.56) Hanover Horton Schools 6 (76,16,41.47) 0 (139,96, 118.00) 0 (268, 232, 249.85) Highland Park City Schools 45 (20,1,858) 13 (511,1,147.72) 0 (226,41,102.37) Huron School District 0 (260, 49, 131.78) 0 (172,135,151.17) 26 (21,18,18.67) InksterCity School District 12 (201,10, 69.76) 18 (6, 4, 423) 27 (22,200) Jackson Public Schools (241,133,177.07) 0 (178,138,159.28) 27 (9, 7, 8.41) Kingsley Area School (424, 165, 279.91) 18 (18,13,16.67) 0 (361,337, 350.52) 0 0 LakevillcComm School Dist 0 (311,116, 225.11) 0 (182,147,166.94) 27 (13, 9,1148) Lansing Public School Dist 0 (176, 87, 127.36) 0 (824264.72) 27 (1,1,1.00) Lincoln Park Public Schools 8 (34,15, 38.64) 0 (69,47, 57,33) 0 (32, 54, 63.00) Mackinac lslandPub Sch 3 (511,17,315.47) 0 (79, 27,4878) 0 (233,138,17459) MancelonaPublic Schools 0 (101,54,7156) 0 (146,130,135.22) 27 (7, 5,6.04) Marcnisco School District 0 (447,165,313.29) 18 (9, 3,6.39) 0 (227,159,189.30) Mason Cons School District 0 (99, 22, 58.44) 18 (17,12,14.83) 0 (47,41,4356) Memphis Comm Schools 27 (346, 4, 126.84) 0 (346, 285,314.00) 0 (228,199,212.33) 0 0 0 Mendon Comm Sch Dist 11 (43, 17, 28.29) 0 (183, 139, 164.11) (32, 24, 29.19) Morenci Area Schools 1 (46, 20, 33.62) 0 (90, 76, 83.83) (104, 94, 98.59) Oak ParkCity School Dist 23 (70, 12, 24.71) 15 (29,13,1794) (491,397, 444.41) Onaway AreaComm Sd 0 (447,176, 309.02) 0 (276,198, 235.28) 27 (17,13,1541) Onsted Community Schools 18 (411,13,230.62) 0 (76, 54, 66.33) 0 (240,210, 225.56) Pellston Public School Dist 3 (342,17, 147.56) 0 (453, 441,446.61) 0 (508,495, 501.59) Pontiac City School District 12 (48, 14, 26.07) 0 (60, 34, 47.28) 0 (51,36,4144) 62 The first number in parenthesis represents maximum rank, the second one represents minimum rank, and the last one represents average rank. 86 Table D (cont’d) Counts of Appearing in the 20 Least Efficient Public School Districts School District Name for Math Test Math Science Grad. rate (efficiency rank) (efficiency rank) (efficiency rank) River Rouge City Schools 22 (35,7,18.87) 0 (45, 26. 33.22) 27 (10, 8, 8.59) River Valley School District 22 (192,ll,76.44) 0 (338, 272, 303.22) 27 (12,10,10.85) Saranac Community Schools 0 (506.490.500.60) 0 (501.496.497.94) 25 (21.18.18.93) South Haven Public Schools 0 (331,4219540) 0 (133,101,119.39) 20 (2219,2015) Southficld Public Sch Dist 5 (104.13.49.20) 5 (33, 17, 23.94) 0 (339.266.300.67) Springport Public Schools 18 (179.7, 103.22) 1 (29, 20, 25.78) 0 (33, 26, 29.78) Tahquamenon Area Schools 0 (129.67.102.18) 16 (23,13,18.39) 0 (123,87,108.85) Vanderbilt Area School 26 (721034.67) 0 (104.82.91.50) 0 (509.505.507.44) Waldron Area Schools 27 (79,1,26.13) 0 (89, 64. 73.50) 0 (143.122.129.70) Warren Woods Public Schs 7 (118.18.61.89) 0 (69, 60, 66.06) 0 (486.460.473.04) Webbcrville Comm Schs 18 (383. 14, 230.16) 18 (13, 7, 10.44) 5 (22, 20.21.33) Westwood Community Schs 20 (74. 14, 29.02) 0 (46.23.3094) 0 (498.472.483.59) WillowRunCommSchs 0 (113,25,67.33) 18 (12, 8.9.50) 0 (214,170,19848) 87 REFERENCES 88 REFERENCES Aigner, 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Y. 91 CHAPTER 3 MIGRATION AND ECONOMIC GROWTH I. Introduction The study of internal migration in the United States has been a long and respectable tradition in the field of regional development, economic growth, and labor mobility. Early studies investigated the relationship between migration and the output level or the rate of economic growth, while recent studies emphasized more the impact of migration on the speed of convergence of economic growth between different areas. There is substantial evidence that internal migration does speed up the convergence of economic growth between different areas. Barro and Sala-i-Martin (1992) include migration in a modified neoclassical growth model to make endogenous migration as a source of linkage between population growth and the log of per capita income. The estimated parameter of convergence speed is much higher in the model with migration than the model without migration (about 30~50% higher). Persson (1994) also found that migration has a positive though small effect on the speed of convergence in per capita income across the twenty-four Swedish counties from 1906 to 1990. If internal migration improves the convergence across different economies, it implies in-migration will lower the speed of growth in the rich area, and speed up the growth in the poor area. Out-migration has opposite effects. However, what we want to know is how will migration affect income growth when we control for the level of income. 92 The simple Solow model merits that the capital stock in steady state is determined by the intersection of break-even investment ( n+g+ 5) k and the actual investment sf(k). Other things equal, the higher the growth rate of population n, the lower the level of capital stock in steady state is. Since output is an increasing function of capital stock, therefore, the level of output in steady state will be lower too. To be one of the positive components of population, net migration might have a negative relationship with the output level in steady state. However, there are many early empirical studies finding a positive relationship between the net migration and the level of per capita income. Okun (1968) found that internal population migration tends to increase the rate of economic growth of a country. Olvey (1972) also found that the in-migration responds to both employment growth and wage levels. Greenwood (1976) provided evidence that white and nonwhite migrants have different performance, while the former is more responsive to the growth of job opportunities, and the latter is more responsive to high income levels and income growth. To explore the possible reason that explains the positive impact of migration on the economic growth, we consider that the migrants may have different characteristics between different groups, such as between white people and nonwhite people. There may exist self-selection behavior that people who carry more hmnan or physical capital are more likely to move to find a better environment. Our data also support this possible reason. About 80 to 90 percent of migration flows is constituted by white native population in most of states. The other issue we are concerned with is that the net migration and the level of per capita income may have a circular relationship. That is, the observed positive 93 relationship between the net migration and the level of per capita income may come from the attractions of higher income level for the migrants, but not vice versa. To explore this simultaneous relationship, a simultaneous-equations model should be adopted, such as Greenwood (1976), Greenwood (1978), Olvey (1972), and Okun (1968). In this paper, we will use a recently developed econometric approach “Dynamic Panel Data Model” to estimate the GMM coefficients for the relationship between migration and growth. In Section II, we review some previous studies in the migration model, and empirical studies of the migration and economic growth issues. Section III introduced the methodology of dynamic panel data we used in our analysis. Section IV describe the specification of our model, the data set used in our model is also summarized as well. Section V reports the regression result, and Section VI concludes. 11. Literature Review Most of the early studies on the migration and economic growth use the cross- sectional data model. Okun (1968), Olvey (1972), and Greenwood (1976) employed a simultaneous equation approach for their estimation since they believed there are causality relationships between migration and economic growth. The econometric methodology of two-stage least squares or three-stage least squares was applied to estimate the system of simultaneous equation. In addition, they all used the data for the United State. Okun (1968) focused mainly the effect of interstate migration on the inequality of per capita income for 1940 to 1950 among the states in the United States. He claimed 94 that at that time labor was generally in short supply as a result of the World War II and its after-effects, therefore, an inflow of migration may be relatively more beneficial to the receiving region than in a more normal time period. Two of the endogenous variables in Okun’s model are net migration rate and the change of per capita service income“. In addition to the change of per capita income, the explanatory variables for net migration rate include the level of per capita service income, the change of agricultural employment, and the fertility rate. Turning to the growth equation, the level of per capita service income, racial composition of migration streams, and age-sex composition in migration as well as the net migration are used as the explanatory variables, in which the net migration and age-sex composition in migration are endogenous. Age-sex composition in migration relative to that in total population is the third endogenous variables in Okun’s model which is determined by the fertility rate and net migration in definition. Okun found that the states with relatively high service incomes per capita tend to attract migrants. However, the decline of agriculture share in the labor force causes out- migration to increase, which is in conflict with the fact that the net migration and change of agricultural employment have positive correlation with each other in the data set. Okun suggested this maybe because those factors affecting net migration of labor between the state’s farm sector and other states are of more considerable importance than those factors affecting net migration of labor between the state’s nonfarm sector and other states during the 1940’s. This will contribute to a net positive correlation between 63 Note that Okun defines service income per capita as total income per capita minus property income per capita. 95 the net migration and the change of the agricultural employment. He also found a significant but negative effect of migration on the growth of service income per capita. Okun tried to explain this striking result by examining the correlation coefficient between the level of per capita service income and its growth rate. Because they are so strongly positively correlated, Okun suggested that migrants necessarily moved in the direction of states with both high level of income and growth rate and it is difficult to separate these two effects. He concluded that it was the high level but not the large increase in service income per capita, which attracted migrants to the receiving states since the coefficient for the level of per capita service income is significantly positive. Turning to Okun’s growth equation, he found that high levels of service income per capita tended to contribute to large increases in service income per capita. Besides, the positive net migration also tended to contribute positively to the absolute growth in service income per capita. Okun’s finding concerning the income level and the growth rate is not consistent with the literature on the convergence of economic growth. However, he did find that net migration and income level or income growth and net migration have positive and significant relationship. Unlike Okun’s use of the state as the unit of observations, Olvey (1972) did related empirical work using data for the 56 largest Standard Metropolitan Statistical Areas (SMSA’s) in the United States for the period of 1955 to 1960. He defined economic growth as employment growth, and also claimed that the employment growth and migration involve a circular relationship. In his multi-equation model, he specified 96 two employment growth equations in manufacturing and service sectors, three migration equations for in-migration from contiguous states, long distance in-migration, and out- migration, as well as three identities for prospective unemployment“, net population growth, and growth of total employment. Besides, he used population growth without migration, industrial composition index (employment demand side), metropolitan wage, income level, and climate (employment supply side) to be exogenous variables. Most of his regression coefficients had expected and significant signs. He found that manufacturing employment growth is deterred by high wage levels and stimulated by net population growth and a mild climate. Service employment growth is closely related to manufacturing employment growth and to population growth and income levels. In- migration responds to both employment grth and wage levels. Short distance or contiguous in-migration is significantly higher for metropolitan areas located in low- income regions. Long distance in-migration is responsive to a mild climate as well. His findings did support the apparent strength of the connection between regional employment growth and migration pattern. Besides, one of the most striking results in Olvey’s model is that the responsiveness of out-migration to prospective unemployment is positive and significant. Thus out-migration seems to be explained largely in terms of push factors on the wage and employment condition at the origin. Greenwood (1976) utilized race specific data relating to the 100 largest Standard Metropolitan Statistical Areas (SMSA’s) in the United States for the 19505 and developed a simultaneous-equations model of migration and urban change for white and 6“ Ovley defined the prospective unemployment as the total increase in population less the increase in employment, assuming zero out-migration. 97 nonwhite civilian labor force members. In his model, he believed income, employment and unemployment are important determinants of the direction and magnitude for migration. Hence he constructed a larger system of equations than Okun’s and Ovley’s and included 12 endogenous variables (out-migrants, in-migrants, employment change, unemployment change, income change, and natural population change, each for whites and nonwhites) in his model. The most interesting finding in his regression results is that no endogenous variables in the out-migration equations are significant, that is, there are no important relationships between the change of income, employment, unemployment and the migration. On the contrary, in the in-migration equation, the regressions results show that the growth of income and employment has positive and significant effect on nonwhite in-migration, while the growth of income is positive and significant related with white in-migration and the growth of unemployment discourages white in-migration. There is also some evidence for the significant relationship between migration and economic growth from the countries other than the United States. Greenwood (1978) estimated a simultaneous-equations model of internal migration and regional economic growth in Mexico for 32 states for the period of 1960 to 1970. By using ordinary least square, two-stage least squares and three-stage least squares, he estimated a system of 10 equations, which contains migration equations, labor force equations and earnings and earnings concentration equations. Eight endogenous variables, in-migration, out- migration, the rate of employment growth in agricultural, manufacturing, and other sectors, the rate of change of unemployment, the rate of change of earnings, and earnings concentration, are included in his model. 98 Greenwood used both of the growth of employment and earnings to proxy the concept of economic growth. He found that internal migrants in Mexico are quite responsive to employment opportunities. More job opportunities (employment growth) attract more migrants. However, the regression result showed the effect of unemployment rate and its growth rate on migration is positive and significant, which is counterintuitive. For the employment growth equation, in-migration is helpful for the employment growth, while out-migration discouraged the employment in most of sectors. In the earnings growth equations, in-migration has positive and significant effect on earnings growth, which implies labor demand shift derived from in-migration dominates the labor supply shift (in-migration has downward pressure for wage). lII. Methodology of the Estimation 3.1 Dynamic Panel Data Model Recently, the panel data model has become influential in growth estimation, compared to cross-sectional estimation in most of earlier literatures. Hsiao (1986) claimed the major advantage of using panel data is that it provides a larger information set than conventional cross-section data or time-series data, increasing the degree of freedom, hence improving the efficiency of econometric estimates. We believe a number of unobservable individual-specific, time-invariant fixed effects, which are responsible for individual income level in steady state exist in our model. Panel data estimation suggests that in the presence of those fixed effects, the cross-sectional error term v... can be decomposed into two terms u,, and 77., where 77, is unobserved state-specific fixed 99 factors that we mentioned above, and u... is usual error term. We assume u... to be independently normally distributed across individuals with zero mean. The general model to be estimated in this essay is of the following form: P y... = 261.32,...) +13'(L) x... + 1., +11, +1... , t = q +1,...,T, ; i = 1,... N, (3.1) k=l where y,, is dependent variable, that is, log of per capita income in the growth equation and net migration rate in the migration equation. We think that the grth rate in the current period may be partly determined by its value in last period, and net migration rate may be also closely correlated with its previous level because the area with more migrants may attract more people moving in than other areas. Therefore, the dependent variable should be auto-regressive of some order. We include the lags of dependent variable in the right hand side of the structural equation. Since this kind of models capture the dynamic property, it is also referred as “dynamic panel data model”. Here x,, is a vector of explanatory variables except the lags of dependent variables, which may or may not correlated with the error term, ,B(L) is a vector of associated polynomials in the lag operator, q is the maximum lag length in the model, and it, is time specific effect that could capture the random shocks maybe present in a particular period. The variable T, is the number of time periods available on the ith individual, which is small and the number of individuals N is large. In our model, the maximum value of T, is 7 (decennial data from 1930 to 1990), and N equals 486’. 6’ This includes 48 states in the United States. We exclude Hawaii, Alaska, and Washington DC. because they are very different from other states. 100 We can also write the general form of our model in the following form; yr! =mt6+vlt2 (3'2) where W., is a data matrix containing the time series of the lagged dependent variables, the x’s and the time dummies. The error term is v" = 11, +111. , Which is the sum of individual effect and usual error term. 3.2 Endogeneity Problem Since 11, is unobservable and constant over time. even W., only contains the exogenous explanatory variables, E(W.,v,,) will not be zero. Therefore, OLS estimates will not be consistent. In order to remove the individual fixed effect, there are several transformation methods available. One of them is the fixed effect transformation: yr: _y1 =(VVu—VT/n)5+(n1_nt)+(uu—l71)=(I/V11_W11)8+(u11_l71) where y, is average value of y,, across time. It is the same for W, and 17,. However, the fixed-effects transformation is not well suited because the errors after the fixed-effect transformation are u” — 17,. and E, is correlated with all W.,. Instead of the fixed effect transformation, first differencing is preferred. After first differencing, the equation becomes: yu —yl,l-l = (W11 _I’Vt,t-I)8+(utt —ut,1-l) : Ayn = AWIS+Au11° Then we have 101 E(AVVIlAut) = 1304/1111”) + E(W.:1—1“1,1-1) — E(”/l:t-lu'l ) - E(VV1'ru1,t-1)° (33) l I In order to get consistent OLS estimators, we need the four terms in the right hand side of equation (3.3) to equal zero. Generally, we always assume W., has no correlation with the error term in past periods, which means the last term of equation (3.3) is zero. However, the other three terms in our model are not zero. Since W., includes lags of the dependent variable, the assumption of strictly exogeneity is not satisfied. In this situation, we need to allow the existing of correlation of W., with future error term. To see how this works, suppose W., only includes y,.,_, for simplicity. yll = BlyIJ-I +111 +utt (3'4) Let W., = y,',_,, then W... , and u,, are necessarily correlated because E04]: um) = E(ynun) = E(u121) : Var(uu) > O s ,t+l where u,, is also correlated with all other future values of W.,. E(u,, III/”,WU_,,...,W“,11,)=0 is also known as weakly exogeneity condition. Therefore, the third term in equation (3.3) is not zero, either. Beside the problem of lags of dependent variables, there is another endogeneity‘56 problem with our model. Since one or more of the explanatory variables, such as net 6" Economically endogenous and Econometrically endogenous: The former means variables that are jointly determined within the specification of the economic model, while the latter one describes the variables as they are determined simultaneously with the dependent variables, that is, correlated with the error terms. 102 migration rate in growth equation, may be determined simultaneously with the dependent variable, E(x,, u,,)¢0, then E( W., 1.1,.) at 0. Similarly, E( W.,, a...) ¢ 0 3.3 Choices of Instrumental Variables In our estimation, the instrumental variable method is used to deal with the endogeneity problem. There are many choices of instrumental variables. Anderson and Hsiao (1982) proposed two simple choices. One possibility is to use the fact that AW,” is uncorrelated with Au“ under weak exogeneity, and we also assume AW,” is sufficiently correlated with AW”. Then the model Ayn =AWHS+AuH (3.5) can be estimated by pooled 2SLS using instruments AWL”. Note here t=3, T since we lose one more observation by using instrumental variables. The second possibility to be the instrumental variable is lagged levels of W... For instance, WW can be the instrumental variables for AW... The disadvantage with the previous two procedures is that they do not use all available instruments, therefore, cannot be expected to be efficient. Arellano and Bond (1991) suggested not only W.,,“ W.,,2 are good instrumental variables, but also any further lags of W., are. They also tested several specifications for dynamic panel data by estimating employment equation. Among eight different equations, which includes one-step GMM, two-step GMM, Anderson and Hsiao type estimates, OLS, within-group...etc., they found that the GMM estimators offer significant efficiency gains compared to other simpler IV alternatives, and produces estimates that are well determined in dynamic panel data models. 103 Let us define the matrix of GMM-type instruments as follows: W3 0 Z, = 0 _ 0 where W0 I! is: 8=[(ZW°‘Z.)A~(ZZIWC°)] [28"2.>A.] 0 0 W3 0 0 W3 5 0 0 0 a(W,,,W,,,..., where AN =(—IIVZ:Z,'H,Z,)—l a 0 W1.7'-1_ (3.6) W”). The general form of linear GMM estimators of 6 l is, first differencing in our estimation. For one-step estimation, we use 2 -l 0 —l 2 —1 O 0 —l 2 O 0 W i and y: denote some transformation of W, and y,, that . c o A. A“ A. . and if u,, are heteroskedastrc, a two-step estrmator use H, = ulu, , where u, 18 transformation of one-step residual. For instance, the GMM-type instrumental variable for equation (3.1) is "y” x,, x,, 0 0 0 0 0 0 0 0 0 0 0 0 Z- O 0 0 y,, yd x,, x,2 x,, O O 0 0 0 O 0 0 ' ' 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 y,, y,, y,“ )1” x1, Note that the most distant observation used as instrument is y,, for y and x,,, x.) for x here since we first-difference our original model. Therefore, one more observation is lost. 3.4 Statistical Tests There are several statistical tests to measure the efficiency of the model. The first one is Wald test statistics, which measure the joint significance of explanatory variables. The second statistics is Sargan test statistics that tests the validity of instrumental Finally, the m2 test statistics is a test for the lack of second-order serial variables. correlation of the errors. 105 IV. Specification of the Model In this section we apply the strategies for estimation and testing outlined earlier to a model of migration and economic growth, using decennial data for forty-eight states in the United States from 1930 to 1990. Alaska, Hawaii and Washington DC. are not included in our estimation because their characteristics on economic and social aspects are very different compared to the other states. We consider the dynamic migration and economic growth equations in the following: The migration equation we estimated in our model is as follows: m” =ym +91ny..+¢X/3+N,"+nf’+u,": (4.1) 1,1—1 The growth equation we estimated in our model is as follows: 1“ yu _ In yl,l—l = 61“ le—l + Bmu—l + WXJ‘i-r + A); +rlty +u1i/ (4-2) 3111))”: alnytJ—l +Bmt,t—l +wa +1)! +111), +111): (4'3) t,t-l Here the subscript i indexes 48 states in the United States, the subscript t = 1930, 1940, 1950, 1960, 1970, 1980 and 1990, and X ,",'.X 5 represent the exogenous explanatory variable matrix for the migration and economic growth, respectively. Considering the data used in our regressions, we should distinguish the flow variables from the stock variables. Note the time subscript t in our specification has different meanings for flow variables and stock variables. For flow variables, such as the net migration, the growth rate of population. . .etc., t represents the current decade instead 106 of a specific year. Hence, the variable with subscript t represents the flow amount or the value change during the decade. On the other hand, for stock variables, such as the average years of schooling completed, the number of farms per person. . .etc., t represents the specific year at when the stock variables were measured. In the following we introduce variables used in our model, and descriptive statistics is reported in Table 1. The main focus in this paper is on migration. We use the migration rate, which is the percentage of net inflow of the migrants in total population for each state, to be the dependent variable in the migration equation. As we mentioned earlier, the migration rate is also one of the explanatory variables in the growth equation because we suspect the migration rate and growth rate have causality relationship with each other. When the migration rate is positive, the state attracts people to move in. On the other hand, when the migration rate is negative, the state is losing residents. We can see the migration rate is pretty high in 19403 and 19505, for both moving in and moving out. North Dakota and South Dakota always experience large out-migration with the migration rate around 15~16% before 19505, while Florida and Nevada experience large in-migration with a migration rate of up to 30% in some decades. We can also find that after 1950s, both of the lowest and highest migration rate increase a lot decade by decade. 107 Table 1: Data Statistics Summary by Decades Variable“ 1930 I 1940 I 1950 l 1960 j 1970 I 1980 1 1990 Area 61655.98 (46819.13) Total Population 2547.71 2729.29 3122.90 3702.06 4195.54 4678.00 5134.42 (2529.20) (2690.55) (3101.28) (3785.45) (4361.41) (4745.77) (5505.94) Total P0pulation Growth 7.94 15.04 18.90 13.1 1 15.81 8.71 __ (7.38) (13.96) (18.94) (12.62) (14.43) (10.97) P0pu1ation Density 0.09 0.10 0.11 0.13 0.15 0.16 0.17 (0.15) (0.15) (0.17) (0.20) (0.22) (0.23) (0.24) Minority Race Share 10.55 10.20 9.92 10.08 10.42 13.57 14.92 (13.22) (12.63) (11.20) (10.17) (8.86) (10.02) (9.38) Absolute Value of the 4.37 8.35 8.66 6.33 7.64 5.40 Migration Rate (4.53) (6.98) (8.15) (5.96) (7.28) (5.19) " Number of Farms Per 62.83 57.12 45.33 28.47 19.51 14.43 13.28 Hundred Persons (34.80) (30.76) (28.40) (21.02) (17.07) (12.98) (12.31) figiiiflrig 6.94 5.96 7.62 7.46 8.33 7.77 7.32 Employees (4.66) (4.22) (5.05) (3.87) (3.50) (2.98) (2.73) Investment in __ __ 42.41 58.29 110.73 299.75 382.81 Manufacturrng (23.49) (30.48) (42.75) (129.63) (171.08) Percentage 0i Foreign 9.83 7.20 5.46 4.07 3.31 4.10 4.62 Born Population (7.54) (5.88) (4.44) (3.26) (2.74) (3.36) (4.38) Per Capita Income 617.63 536.83 1401.27 2058.33 3675.81 5077.06 19351.19 (224.24) (191.59) (324.71) (407.24) (544.63) (667.40) (3202.25) Groyvth Rate of Per -12.47 173.75 48.36 80.71 38.59 280.93 __ Capita Income (7.57) (42.88) (9.46) (13.74) (7.25) (32.84) Percentage of Urban 46.02 47.75 55.57 61.95 65.77 66.59 67.06 Population (19.92) (18.24) (16.00) (14.85) (14.37) (14.42) (21.91) Average Years of Adults __ 8.42 9.45 10.05 10.92 11.88 12.53 Schooling (0.85) (0.77) (0.68) (0.62) (0.55) (0.42) :iiiertiiztiesiiixium __ 24.99 34.31 41.35 52.64 66.90 75.98 13 ducaflon (5.76) (7.90) (7.21) (7.89) (7.33) (5.51) Crime Rate __ 1.71 1.59 0.92 2.31 5.43 5.05 (0.69) (0.62) (0.38) (0.89) (1.40) (1.41) Percentage of Age of 9.69 8.56 11.20 11.63 8.54 7.54 7.60 Under 5 Pepulation (1.49) (1.49) (1.11) (0.92) (0.57) (1.18) (0.64) Note: Numbers in parenthesis present standard deviation. 67 Detailed data definition and source please see Appendix A. 108 The growth variable is the other one of main variables in our model. In the growth equation, we use the logarithm of per capita income in thousand dollars in state i at the beginning year during a specific decade t, to be the dependent variable. It is also one of the explanatory variables in migration equation. In some regressions, we replaced the logarithm of per capita income by the growth rate of per capita income for comparison. Although theoretically lny .- lny M is approximately equal the growth rate, empirically their values are somewhat different, especially when the per capita income grows rapidly. For example, for state of Maine, lnymo= 8.09, lnymo= 8.40, lnyI990 =9.82, however, yg1980 = 35%, yg1990 = 317%. This makes the coefficients in our estimations using different measures of economic growth change a lot. Note that the coefficient 01 in equation (4.3) equal (1 + c) in equation (4.2). From the previous studies on the convergence of economic growth, c is expected to be negative. The region with low-income level grows faster than the region with high-income level. Therefore, we expect or much smaller than 1, and if 01 approaches to 1, we will have the unit root problem. It also means that the income level has no impact on the economic growth rate, which is contradicted by the theories. Besides the growth variables, several geographic variables are included in the right hand side of the migration equation. Persky and Kain (1970) argued that social factors such as the racial composition are as important as the economic opportunities to explain the flow of migrants between different areas. The migrants always face the problems of assimilation in the destination area. People might like to live with others of the same ethnic group. This is why there 109 are always Chinatown, Italiantown...etc. in the metropolitan area. Persky and Kain (1970) also prove that the racial distribution of employment is a prime determinant of the racial composition of migration. In our estimation, we do not have the data of racial distribution of employment, however, we believe the racial distribution of population also has similar impacts on the migration flow. Therefore, we include the percentage of nonwhite people in total population to be one of the explanatory variables in the migration equation. Since the internal migration flow is composed mostly of white people, we expect a negative relationship between net migration and the percentage of nonwhite population. Some people argued that the characteristics of states possibly affect interstate migrants and international immigrants differently. For example, international immigrants tend to choose the cities with major entries points such as an international airport or harbor as their migration destination, regardless the level of per capita income, public security, and the geographic environment. . .etc. While the internal migrants may be more concerned with a better living environment and more job opportunities when they make the decision to move. What we focus on in this paper is the internal migration within the United States, however, the migration data we have were measured as the net amount of people who move into the specific state, regardless of point of origin. In order to separate out the impact from international migrants, we include the number of foreign-born people in both of the migration and growth equations. The percentage of urban resident in total population is expected to positively relate to the migration rate. A more urbanized area might have more job opportunities. Therefore, it maybe attracts more people moving in. When people consider moving, the 110 amenity of an area matters. For example, the mild weather is a positive factor, while crime is a negative one. Since the weather in an area doesn’t change much over time, the two weather variables, highest temperature in summer and lowest temperature in winter, are constant over time. Now let us consider the factors affecting the growth rate. Population growth is an important one of them. In the simple Solow model, the population growth is expected to have a negative impact on the level of income in steady state. The accumulation of human capital and physical capital is also a positive factor to the economic growth. The former can be measured by the education level for a region, while we use the new capital establishment to measure the accumulation of physical capital. We have two measures of education level in our estimation. The fist one is average years of schooling completed for persons 25 years old and over. The other education variable is percentage of persons 25 years old and over who have at least high school education. In the modern growth literature, accumulation of human capital is expected to have positive effect on economic growth. Industry decomposition may also have impacts on economic growth. The number of farms per thousand people and the percentage of people who work for manufacturing industry in the total population are our industry variables. V. Regression Results We compare the regression results estimated by different econometric methods for migration and growth equation in Table 2A and Table 2B respectively. 111 The first column in Table 2A and Table 2B reports coefficients and standard errors estimated by Anderson and Hsiao type of instrumental variable method, while the other three columns are estimated by GMM method. All four estimations use the transformation of first differencing to remove the unobserved individual effects. In addition, they are all estimated by using variables in levels as instruments. Moreover, robust variance-covariance matrix is also applied except in the second column. Note that the m2 statistics for all of four estimations are small enough that we can accept the null hypothesis of no serially correlation between error terms. Besides, the Sargan Tests in all GMM estimations are significant, except the last column in Table ZB, which shows we use the right instrumental variables. The first two GMM regressions are estimated by one-step procedure and the last one is estimated by two-step procedure. However, the evidence from the simulation of Arellano and Bond (1991) showed that the standard errors are not reliable in two-step estimation when we have finite sample size. In their simulation, the standard errors of two-step GMM estimates are much smaller than of one-step GMM estimates. Therefore, they suspect that most of this apparent gain in precision may reflect a downward finite- sarnple bias. We can also see the same situation occurred in our estimation. The standard errors of the estimates from GMM two-step estimation in the fourth column are always much smaller than that in the second and third column, which uses GMM one- step estimation. 112 Table 2A: Migration Equation in Different Estimation Methods Estimation Method AHi GMM] GMer GMM2 Variable Transformation First Difference First Difference First Difference First Difference Time Period 4 4 4 4 Dependent Variable Migration Rate Migration Rate Migration Rate Migration Rate Instrumental Variable 1y: 1 lag 1y: 2 lag 1y: 2 lag 1y: 2 lag m: l lag m: 2 lag m: 2 lag m: 2 lag Migration Rate in Previous 0.6030 -0.0571 -0.0571 -0.0593 Decade (0.2683) ** (0.0979) (0.0665) (0.0441) lhiiagéhgthglgggflihag Year 8.5653 16.6719 16.6719 14.6598 it it it of Current Decade (6.8970) (5.8760) (6.5940) (4.4380) {13:33: 5]: :ggm’i‘n: Year -2.8937 12.3922 12.3922 11.5140 *# 1* t of Previous Decade (7.2080) (5.6610) (4.1660) (2.6780) "‘ Percentage of Urban -0.2894 -0.2553 -0.2553 -0.1900 Population (0.1627) * (0.1259) ** (0.1854) (0.1338) Crime Rate -1.9685 -2.5643 -2.5643 -2.2532 (1.1890) 1' (0.9496) ** (0.9198) ** (0.5788) ** . . -0.0701 -0.0566 -0.0566 -0.l317 Mummy Race Share (0.1933) (0.1771) (0.1101) (0.0631) .. Percentage of Foreign-Bom 1.4470 0.3261 0.3261 0.2534 Population (0.5389) *"‘ (0.3674) (0.3331) (0.2407) Constant -4.5875 -12.7l91 -12.7191 -11.7520 (7.5690) (6.6290) * (6.9890) * (4.4090) ** Year Dumm . 1960 7.5526 -4.9299 -4.9299 -4.8424 y' (10.7100) (8.4510) (7.4490) (4.4160) Y ar Dumm , 1970 11.0603 8.8254 8.8254 8.6508 c y' (4.5650) .. (5.0420) * (4.2220) .. (2.3530) .. . 1.6988 4.7840 4.7840 4.3251 Yea’ Dm‘m‘y' 1980 (7.6340) (7.7170) (6.6100) (3.9440) Wald Test" 77.30 ** 103.7 ** 120.3 ** 246.2 ** Sargan Test" -- 53.62 ** 53.62 ’1‘" 27.25“ m2 Test -0.5158 -1.852 -1.901 -1.905 Note: Number in parenthesis represents standard error. One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks (**) indicates significance at the 95 percent confidence level. 113 Table 2B: Growth Equation in Different Estimation Methods Estimation Method AHi GMM] GMer GMM2 Variable Transformation First Difference First Difference First Difference First Difference Time Period 4 4 4 4 Dependent Variable Logarithm of Per Logarithm of Per Logarithm of Per Logarithm of Per Capita Income Capita Income Capita Income Cagita Income Instrumental Variable 1y: 1 lag 1y: 2 lags 1y: 2 lags 1y: 2 lags m: 1 lag m: 2 lags m: 2 lags m: 2 lags Logarithm of Per Capita 0.1235 0.1298 0.1298 0.0980 Income 10 Years Ago (0.0749) * (0.0505) 1‘" (0.0742) "‘ (0.0600) * Migration Rate in Last 10 0.0025 0.0019 0.0019 0.0021 Years (0.0018) (0.0009) ” (0.0010) "' (0.0006) " Natural Population Growth in -0.0423 -0.0471 -0.0471 -0.0443 Last 10 Years (0.0125) " (0.0074) " (0.0107) ** (0.0080) ‘1‘ Average Years of Adults 0.0407 0.0554 0.0554 0.0673 Schooling (0.0268) (0.0269) *s (0.0262) n (0,0211) .. Percentage of Manufacturing -0.0003 -0.0022 -0.0022 -0.0009 Employee (0.0035) (0.0033) (0.0032) (0.0026) Percentage of Foreign-Bom 0.0039 0.0027 0.0027 0.0025 Population in Last 10 Years (0.0038) (0.0026) (0.0035) (0.0024) . . 0.0001 0.0001 0.0001 0.0001 lnvestrnent 1n Manufacturing (0000]) 2 (0.0001) n (0.0001) n (0.0000) n Constant 0.3601 0.3549 0.3549 0.3731 (0.0832) " (0.0522) '1'" (0.0827) " (0.0684) '1“ . 0.1588 0.1500 0.1500 0.1319 Decade Dmmy' 1970 (0.0603) .. (0.0424) *s (0.0598) as (0.0488) 1. _ -0.3156 -0.3472 -0.3472 -0.3414 Decade 9mm" 1980 (0.0764) .. (0.0492) n (0.0743) ** (0.0580) n . 0.8630 0.8460 0.8460 0.8314 Decade Dummy 1990 (0.0774) H (0.0466) *s (0.0743) "1 (0.0588) as Wald Test” 173.8 1“ 362.7 "1‘ 262.6 " 753.2 "1‘ Sargan Test" -- 32.66 " 32.66 "‘"' 20.10 m2 Test -0. 1335 -0.3592 -0.3898 -0.3713 Note: Number in parenthesis represents standard error. One asterisk (‘) indicates significance at the 90 percent confidence level. Two asterisks (") indicates significance at the 95 percent confidence level. 114 In the rest of this paper, we will focus on the estimation using GMM one step without robust variance-covariance matrix and refer it as our base regression. The second column in Table 2A represents the estimated relationship between the migration rate and its explanatory variables. The result suggests that the previous migration rate does not have an important impact on current migration rate. That is, the migration rate does not have a dynamic property. However, the previous income level and the growth rate of income do have significant effect on migration rate. If we transform lny and lny(-l) into 1ny-lny(-1) (growth rate), and lny (income level), we will get the coefficient for growth rate with value of —12.3922, and the coefficient for previous income level with the value of 29.0641. Therefore, the migration rate is positively related with the previous level of logarithm of per capita income. When per capita income increases one percent, the migration rate will increase 0.29 percentage points. However, the growth rate of income is negatively and significantly related with the migration rate. It shows that people do not move to the area with high growth rate, but to the area with high level of per capita income. It may be clear that people will choose to move into the area with higher income level conditional on the same growth rate. However, it seems surprisingly that people prefer the area with the lower growth rate when conditional on the same level of income. Another significant impact of explanatory variable comes from the crime rate. This is a negative factor to the migration flow as we expected. The GM estimates suggest that one more percentage point of the crime rate will reduce about 2.56 percentage points of the migration rate. Besides, the percentage of urban population also has negative impact on the migration rate in our estimation. It is a surprising result because we expect people will move to the state with large city, which can provide more 115 job opportunities. On the other hand, large cites may be congested, which can generate incentives for out-migration. Now let us consider the growth equation. The second column in Table 2B represents the estimated relationship between current income level and its explanatory variables. Note that the coefficient of lagged per capita income is significantly positive and much smaller than one. Remember that in equation (4.2) and (4.3), a (the coefficient of lagged of lny) = 1 + c. In the third column, or = 0.1298, therefore, c = -0.8702. Therefore, the approximate growth rate of per capita income is negatively related with the previous level of per capita income. When the previous level of per capita income increases one percentage point, the growth rate decreases about 0.87 percentage point. The growth rates of different states indeed converge, as expected by the previous studies on the convergence of the economic growth. The migration rate is also a significantly positive factor to the growth of income, though the effect is not large. One percentage increase of the migration rate will increase 1.9 percent of per capita income. We also include the natural population growth in our explanatory variable set. As the Solow model predicts, we also find that higher natural population growth will decrease the level of per capita income. Additions to the population which come from immigration have a positive effect on growth, increasing population through a rise in fertility has positive impact on the level of income. This finding can be explained as follows: Immigrants might bring with them a diverse set of skills which can provide a stimulus for growth. The negative relationship between fertility and growth can be explained easily by a Solow type growth model. 116 Besides, the average year of schooling completed is also a positive factor to per capita income in our estimation. One more year of average schooling will result in a 5.54 percent increase of income. Finally, investment plays a very important role in economic growth. In our estimation, the coefficient for investment is positive and significant. 117 Table 3A: GMM Estimations with Different IVs for Migration Equation Egression 1 2 3 4 5 6 7 Time period 4 4 4 4 4 4 4 Dependent . . Variable Migratron Rate Instrumental 1y: 2 lag m: 2 lag m: 3 lags m: 3 lags m: 3 lags m: All lags 111: All lags Variables m: 2 lag 1y: 3 lag 1y: 2 lags 1y: 3 lags 1y: All lags 1y: 3 lags 1y: All lags Migration Rate in -0.0571 -0.0569 -0.0629 -0.0657 -0.0612 -0.0814 -0.0768 Previous Decade (0.0979) (0.0976) (0.0968) (0.0965) (0.0962) (0.0952) (0.0949) Logarithm of Per gaepgtzglfi°£ ‘" 16.6719 16.0063 16.4933 15.6699 15.4804 15.5294 15.3221 it it it it 0! it it Year of Current (5.8760) (5.7910) (5.8540) (5.7610) (5.7550) (5.7380) (5.7310) Decade Logarithm of Per Eipétiglfifge '" 12.3922 12.4306 12.4402 12.4845 12.4139 12.9049 12.8360 it it It #i it it ti Year of Previous (5.6610) (5.6390) (5.6430) (5.6190) (5.6220) (5.5860) (5.5890) Decade Percentage of -0.2553 -0.2613 -0.2543 -0.2655 -0.2610 -0.2667 -0.2619 Urban population (01259)" (01225)" (0.1252)M (01220)" (0.1218)" (01216)" (01214)" Crime Rate -2.5643 -2.5829 -2.6073 -2.6512 -2.6558 -2.7169 -2.7230 (0.9496)" (09464)“ (09433)" (09392)" (09399)" (09339)" (09345)" Minority Race -0.0566 -0.0747 -0.0552 -0.0795 -0.0840 -0.0828 -0.0876 Share (0.1771) (0.1746) (0.1766) (0.1741) (0.1740) (0.1734) (0.1733) 23:31:52: 0.3261 0.3426 0.3390 0.3593 0.3633 0.3174 0.3210 population (0.3674) (0.3637) (0.3623) (0.3594) (0.3596) (0.3562) (0.3564) Constant -12.7191 -11.9837 -12.5244 -1 1.5872 -11.4394 -11.4591 -11.2969 (6.6290)* (6.5390)‘ (6.6000)‘ (6.5030)* (6.5020)* (6.4770)‘ (6.4760)* Year Dummy: -4.9299 -5.3911 -5. 1205 -5.7045 -5.7330 -6.2909 -6.3322 1960 (8.4510) (8.3990) (8.4290) (8.3660) (8.3730) (8.3180) (8.3240) Year Dummy: 8.8254 8.5341 8.7873 8.4483 8.4295 8.3167 8.2940 1970 (5 .0420)‘ (5.0190) (5.0290)* (5 .0020)* (5 .0060)‘ (4.9810)"I (4.9850)‘ Year Dummy: 4.7840 4.3478 4.7722 4.3002 4.2502 4.3125 4.2586 1980 (7.7170) (7.6830) (7.6890) (7.6530) (7.6590) (7.6240) (7.6290) Wald Test" 103.7 " 104.0 "“" 105.0 ‘1‘ 105.1" 105.1"”'I 106.1 " 106.2" Sargan Test” 53.62 " 54.26 "”" 54.40 ** 55.48 ** 55.67 ** 57.29 " 57.54 "'* m2 Test -l.852 -1.822 -1.860 -l.840 -1.818 -1.888 -1.865 Note: Number in parenthesis represents standard error. One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks (**) indicates significance at the 95 percent confidence level. 118 Table 3B: GMM Estimations with Different IVs for Growth Equation Regression 1 2 3 4 5 6 7 Time Period 4 4 4 4 4 4 4 Dependent Variable Logarithm of Per Capita Income Instrumental Variable 1y: 2 lags 1y: 3 lags 1y: 2 lags 1y: 3 lags 1y: All lags 1y: 3 lags 1y: All lags m: 2 lags m: 2 lags m: 3 lags m: 3 lags m: 3 lags m: All lags 111: All lags Egggmofijfg 0.1298 0.1405 0.1256 0.1339 0.1332 0.1281 0.1283 p (0.0505)" (0.0495)" (0.0497)" (0.0486)" (0.0479)M (0.0483)" (0.0476)" Years Ago Migration Rate in 0.0019 0.0020 0.0018 0.0021 0.0022 0.0022 0.0023 Last 10 Years (0.0009)" (0.0009)" (0.0009)‘ (0.0009)" (0.0009)" (0.0009)” (0.0009)" 2:331: 3:133] -00471 -00434 -0.0458 -0.0422 -0.0421 -00415 -00417 Years (0.0074)" (0.0074)" (0.0074)" (0.0073)" (0.0072)" (0.0072)" (0.0071)" Average Years of 0.0554 0.0506 0.0622 0.0527 0.0516 0.0511 0.0521 Adults Schooling (0.0269)" (0.0259) * (0.0264)" (0.0254)" (0.0246)" (0.0252)" (0.0244)" iifii’éifiigg -00022 -00007 -0.0018 -0.0005 -0.0019 -0.0004 -0.0016 Employee (0.0033) (0.0032) (0.0033) (0.0032) (0.003 1) (0.003 1) (0.003 1) Percentage of Foreign-Born 0.0027 0.0027 0.0023 0.0029 0.0034 0.0034 0.0034 Population in Last 10 (0.0026) (0.0026) (0.0025) (0.0025) (0.0025) (0.0025) (0.0025) Years Investment in 0.0001 0.0001 0.0002 0.0002 0.0002 0.0002 0.0002 Manufacturing (0.0001)" (0.0001)“ (0.0001)" (0.0001)" (0.0001)” (0.0001)" (0.0001)" Constant 0.3549 0.3377 0.3512 0.3402 0.3415 0.3457 0.3453 (0.0522)" (0.0516)" (0.0513)" (0.0507)” (0.0501)“ (0.0503)" (0.0498)" Decade Dummy: 0.1500 0.1643 0.1481 0.1615 0.1618 0.1591 0.1593 1970 (0.0424)" (0.0411)" (0.0417)M (0.0404)" (0.0394)" (0.0402)" (0.0392)" Decade Dummy: -0.3472 -0.3193 -0.3433 -0.3189 -0.3241 -0.3201 -0.3241 1980 (0.0492)" (0.0481)" (0.0484)" (0.0472)" (0.0459)" (0.0470)" (0.0457)** Decade Dummy: 0.8460 0.8679 0.8479 0.8668 0.8646 0.8648 0.8633 1990 (00466)" (00455)" (0.0458)“ (0.0446)“ (0.0435)” (0.0444)” (0.0433)" Wald Test” 362.7 ** 360.9 "'* 363.2 *" 363.7 " 365.8 ** 369.5 ** 370.4 *1‘ Sargan Test“ 32.66 ** 49.05 ** 39.49 ** 53.84 ’1‘ 59.84 ** 56.13 ** 62.65 ** m2 Test -0.3592 -0.3696 -0.4344 -0.4049 -0.4444 -0.3760 -0.4191 Note: Number in parenthesis represents standard error. One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks (**) indicates significance at the 95 percent confidence level. 119 Different sets of instrumental variables are applied in the estimations both for migration and growth equations in Table 3A and Table 3B. The first column is our base regression, and more lags of the potential endogenous explanatory variables are added into the GMM instrumental variable set for the regressions in other columns. We can see the coefficients and significance level do not change much except some insignificant variables, and the regression results are robust across estimations. We can also see the Sargan test improves when more lagged dependent variables and more lagged endogenous variables are added as the instrument variables in our regressions. Table 4A reports the results from alternative specifications for the migration equation. The first column is the base regression. Since we found that the migration rate does not have a significant dynamic property, we remove the lag of migration rate in the second column. The result shows that most of the coefficients do not change much. The fourth column replaces the percentage of urban population by the population density. The results shows that people like to move to the state with lower population density and which is parallel to our previous finding, which shows the state with smaller percentage of urban population attracts more migrants. The last column includes 8 regional dummies in the regression. The level of income still has positive impact on the migration rate, and the growth of income and the crime rate are negative factors to the migration rate. However, urban population loses its significance now. Besides, we find that joint significance decreases a lot. 120 Table 4A: Alternative Specifications for Migration Equation Regression 1 2 3 4 5 Time Period 4 4 4 4 4 Dependent Variable Migration Rate in This Decade hrs ental Variables 1y: 2 lags 1y 2 lags 1y: 2 lags ly and lyg: 2 lags 1y: 2 lags m: 2 lagsL ' m: 2 la s m: 2 lags m: 2 la 3 Migration Rate in Previous -0.0571 __ -0.0429 -0.0648 -0.0559 Decade (0.0979) (0.0972) (0.097 1) (0. 1036) Growth of Logarithm of Per 12 5214 Capita Income in Previous -- -- -- ' ' u -- Decade (5.6320) figf‘gmgizerfg‘fflggxt 16.6719 17.6223 14.7487 28.8798 10.9585 Decade g g (5.8760) .. (6.0830) .. (5.8220) .. (6.6630) as (6.7630) s 50331132111131: ifiergg‘fiflmm 12.3922 1 1.8908 7.1925 __ 10.0878 Previous a“; (5.6610) .. (5.6120) *s (5.4110) (5.7150) s . -0.2553 -0.2795 -0.2572 -0.2000 Percentage °f urban P°p“'a”°“ (0.1259) *1: (0.1332) is " (0.1247) .. (0.1800) . . -35.3526 Populatron Densrty -- -- (13.0300) u -- - Crime Rate -2.5643 -2.2l47 -l.9026 -2.5809 -2.6681 (0.9496) " (0.9794) "“" (0.9834) "' (0.9441) ” (0.9644) " Minority Race Share -0.0566 -0.0572 -0.1006 -0.0644 -0.0146 (0.1771) (0.1849) (0.1761) (0.1764) (0.2026) Percentage of F oreign-Bom 0.3261 0.3905 --0.1 123 0.3303 0.5491 Population (0.3674) (0.374 1) (0.3056) (0.3642) (0.4799) Constant -12.7l9l -l3.4007 -l3.7472 -12.3759 -5.8932 (6.6290) "' (6.8190) "‘ (6.2790) " (6.5910) " (7.5520) Year Dumm . 1 9 60 4.9299 -3.6397 0.9207 -5.2691 -5.8369 y' (8.4510) (8.4050) (8.03 80) (8.4290) (8.5400) Year D . 1970 8.8254 8.7494 11.4339 8.6602 7.8599 “mm" (5.0420) * (5.1530) * (4.7190) ** (5.0270) * (5.2440) Year D _ 1980 4.7840 3.9923 7.9560 4.5859 2.6379 “"‘my' (7.7170) (7.9200) (7.2100) (7.6890) (8.1 160) Wald Test" 103.7 " 98.42 " 111.8 Mi 104.1 in 34.67 " Sargan Test" 53.62 in 41.57 ** 57.79 *"' 55.66 ** 51.62 ** m2 Test -l.852 -l.576 -l.7l4 -l .872 -l.828 Note: Number in parenthesis represents standard error. One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks (1") indicates significance at the 95 percent confidence level. 121 Table 4B: Alternative Specifications for Growth Equation Regression 1 2 3 4 5 6 Time Period 4 4 4 4 4 4 Dependent Variable Logarithm of Per Capita Income Instrumental Variables 1y: 2 lags 1y: 2 lags 1y: 2 lags 1y: 2 lags 1y: 2 lags 1y: 2 lags m: 2 lags m: 2 lags m: 2 lags m: 2 lags m: 2 lags m: 2 lags Logarithm of Per Capita 0.1298 0.1432 0.1668 0.0047 0.0007 0.0959 Income 10 Years Ago (00505)" (00555)" (0.0495) .. (0.0588) (0.0579) (0.0494)* Migration Rate in Last 0.0019 0.0016 0.0023 0.0011 0.0013 0.0015 10 Years (0.0009)" (0.0008)" (0.0009)" (0.0009) (0.0009) (0.0009)* Natural population -0.0471 -0.0486 -0.0478 -0.0459 -0.0450 -0.0450 Growth in Last 10 Years (0.0074)" (0.0069)" (0.0076) ** (0.0069)" (0.0068)" (0.0072)M Average Years of Adults 0.0554 0.0593 __ 0.0683 0.0668 0.0350 Schooling (0.0269) ** (00264)" (00254)" (00251)" (0.0288) Percentage of Adults with High School -- -- (83820:) -- -- -- Education ' figigfiuegg -0.0022 -0.0012 -0.0029 -0.0047 __ 0.0086 *# Employee (0.0033) (0.0031) (0.0034) (0.0033) (0.0039) Number of Farms Per -- __ __ -0.0024 -0.0019 __ Hundred Persons (0.0008) ” (0.0007) *“ girrfilegtjgjlggfifi‘fl;t 0.0027 __ 0.0035 0.0034 0.0021 0.0050 10 Year: (0.0026) (0.0027) (0.0025) (0.0022) (0.0028) * Growth Rate of 0 0043 Percentage of Foreign- -- (0' 0056) -- -- -- -- Born Population ' Investment in 0.0001 0.0001 0.0002 0.0001 0.0001 0.0000 Manufacturing (00001)" (00001)" (00001)" (00001)" (00001)" (0.0001) Constant 0.3549 0.3386 0.3580 0.4284 0.4384 0.4498 (00522)" (00578)” (00532)" (0.0533) .. (00521)" (00528)" D d D mm .1970 0.1500 0.1548 0.1858 0.0957 0.0884 0.1318 “‘1 e “ y' (00424)" (0.0441)M (00439)" (0.0424) *4 (00411)" (0.0415) ** D deD mm , 1980 -0.3472 -0.3476 -0.3244 -0.3649 -0.3597 -0.3189 “3 u y' (0.0492) .. (0.0487) .. (0.0541)M (0.0467) .. (0.0465)" (0.0503)M D de Dumm , 1990 0.8460 0.8564 0.8690 0.7991 0.7980 0.8375 “3 Y' (00466)" (0.0494)M (0.0486)" (0.0462)" (0.0456)” (0.0475) in Wald Test" 362.7 .. 353.1 .... 337.4 1. 421.1 "1 424.5 H 203.6 .. Sargan Test" 32.66 ** 32.99 31.82 ** 33.77 ** 33.01 .. 26.67 * m2 Test -0.3592 -0.5245 0.0132 0.4292 0.4457 -1 .648 Note: Number in parenthesis represents standard error. One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks (**) indicates significance at the 95 percent confidence level. 122 We also try different specifications for the growth equation in Table 4B and the first column is our base regression again. The second column uses the measure of foreign-born population growth instead of the percentage of foreign-born population, and we get very similar result as the base regression. The foreign-born population still has no important impact on per capita income. We replace the average years of adult schooling by the percentage of adult with at least high school education, and now the educational variable becomes insignificant. The result that the average year of schooling completed is positive and significant, but the percentage of high school education is insignificant suggests the overall level of education, instead of distribution of higher education, has important effects on the growth of income. In the fourth column, we add the number of farms per hundred person to proxy composition of industry in our estimation, while in the fifth column, we remove the share of employee in manufacture and leave the number of farm per hundred person to be the only one industry variable. Both of the columns show that the number of farm per hundred person have negative impact on per capita income. The reason may be that our estimation is focused on the period after 1960. During this period, agriculture is no longer the push power for economic growth. The area with less share of agriculture, more share of manufacture and service will have higher level of per capita income. The 8 regional dummies are included in the last column. Now the share of manufacture employees and percentage of foreign-born population become the positive important factors to the income level. This may imply within the same region, different 123 share of manufacturing employee and foreign-born population determine different level of per capita income. Up to this point, we haven’t deal with the possible endogeneity problem caused by causality between the migration rate and the level of per capita income. Due to the restriction of software we used, we can not do actual two stage or three stage least square. However, we can deal with this problem to some extent by adding migration’s explanatory variables into the instrumental variable set of the growth equation, and do the same thing for the migration equation, therefore, get the similar effect of simultaneous equations. Table 5 reports the “quasi-simultaneous” equation results. The additional instrumental variables for per capita income in the migration equation are natural population growth, average years of schooling, and investment. The additional instrumental variables for the migration rate in the growth equation are the percentage of urban population and the crime rate. Some coefficients in the migration equation change the value a lot. but are still significant. The reason may be that we lose one more observation by using investment as instrumental variable for per capita income. However, we can see that the m2 test improves a lot in the migration equation. 124 Table 5: “Quasi-Simultaneous” Migration and Growth Equation Migration Equation Growth Equation Instrumental Variables natural population growth, the percentage of urban average years of population, crime rate schooling, investment GMM-Type Instrumental Variables 1y: 2 lag 1y: 2 lag m: 2 lag m: 2 lag Migration Rate in Last 10 Years -0.6196 0.0020 (0.1249) ** (0.0009) ** Logarithm of Per Capita Income in the 63.5687 Beginning Year of Current Decade (12.7300) ** '- Logarithm of Per Capita Income in the 12.4301 0.1272 Beginning Year of Previous Decade (6.1400) ** (0.0503) ** Percentage of Urban Population -0.1600 (0.1669) -- Crime Rate -4.4001 (0.9688 ** -- Natural Population Growth in Last 10 -0.0465 Years -- (0.0074) ** Average Years of Adults Schooling 0.0553 -- (0.0268) ** Percentage of Manufacturing -0.0023 Employee -- (0.0033) Minority Race Share 0.0947 (0.1951) -- Percentage of Foreign-Bom -0.l691 Population (0.5 109) -- Percentage of Foreign-Bom 0.0029 Population in Last 10 Years -- (0.0026) Investment in Manufacturing 0.0002 " (0.0001) ** Constant -38.6848 0.3563 (7.1060) ** (0.0520) ** Decade Dummy: 1960 Decade Dummy: 1970 9.4034 0.1494 (5.0420) * (0.0423) ** Decade Dummy: 1980 24.3865 -0.3466 (4.4550) ** (0.0491) ** Decade Dummy: 1990 0.8461 " (0.0465) ** Wald Test ** 104.6 ** 364.7 ** Sargan Test ** 45.75 ** 33.38 ** M2 Test 0.4159 -0.3559 Note: Number in parenthesis represents standard error. One asterisk (*) indicates significance at the 90 percent confidence level. Two asterisks (**) indicates significance at the 95 percent confidence level. 125 VI. Conclusion In our dynamic panel data model, the migration rate and the income growth do have significant relationship with each other. The high level of income instead of income growth rate attracts people to move into that state, and the inflow of migrants also increases economic growth. Results also show that per capita income does have dynamic properties themselves, however, the migration rate does not. To deal with the dynamic problem, we use GMM estimation and we find that the serial correlation problem can be improve when we employ more lags of potentially endogenous variables as the instrumental variables. In addition, the percentage of urban population and the crime rate are important negative factors to the migration rate. The area with lower rate of crime committed will lead to larger net inflow of internal migrants. The more surprising result is that people do not move to the area with higher percentage of urban population or higher population density. 126 APPENDIX 127 Appendix: Data Definition and Source Area: Land area of state in 1990, measured by square mile. Source: US. Bureau of the C ensus, collected by Statistical Abstract of the United States (Annual). Imalflopulatign: In thousand persons, 1930-1990. Source: US. Bureau of the Census, collected by Historical Statistics of the States of the United States. Naturalfiopulationfimmh: Percentage of population of age under 5 in total population, in percent. Source: Historical Statistics of the US, Colonial Times to 1970 and Statistical Abstract of the United States (for 1980 and 1990 data). Populafimllensity: Total population divided by land area, in thousand people per square mile. MinoriILRacLShare: Percentage of nonwhite population in total population, in percent. Source: Historical Statistics of the States of the United States. HEW: Percentage of population in urban area in total population, in percent. Source: Historical Statistics of the States of the United States and State and Metropolitan Area Data Book (for 1990 data). MigratiQrLRate: Percentage of estimated net intercensal total migration in total population, in percent. Source: Historical Statistics of the US, Colonial Times to 1970 and Statistical Abstract of the United States (for 1980 and 1990 data). Remntamffiorelgnzflflmmmmn: In percent. Source: US. Bureau of the Census. WW: Current foreign-born population minus previous foreign-born population then divided by previous foreign-born population, in percent. WWW: Total number of farms divided by total population, in number. Source: Historical Statistics of the States of the United States. 128 RemenmgeJLMannfamufinLEmpleefisz Total employees in manufacturing industry divided by total population. Source: Historical Statistics of the States of the United States. InvestmenLjnMnufacmn’ng: New capital expenditure in manufacturing industry per capita, in thousand dollars. Source: Historical Statistics of the States of the United States. Wm: In thousand dollars. Source: Statistical Abstract of the United States (Annual). WWW: Current per capita income minus previous per capita income then divided by previous per capita income, in percent. W: In years. Source: Statistical Abstract of the United States. W: In percent. Source: Statistical Abstract of the United States. grim: Offenses known to the police in urban communities, measured by rate per 100 inhabitants, sum of murder, non-negligent manslaughter, forcible rape, robbery, aggravated assault, burglary-breaking or entering, larceny theft, and auto theft. 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