r... 0.. 3.1.5:: .6 .9 ct. . I. I. .1 . 9.1. : .3»... 5.5. 2. .53.. e 3 A. 1 car. _.H. ,J u. “HIT. as: a; .6. N2. 3 : 3,. 5! .3. t 4.1.»... r n A 3 4... .15 |‘. J VI: {(1.71 ‘ an. 3 wt 4.. 3,an 5.5.: . ., - .axwmfi .. . .. m. ,. .. ., ms Rxfiuh 561.“...zfimfi4s . H. : . :5 .fifiwtv. 3a.. z e- ‘ ;.........u..b..3.9n. . . Wm. . .J....ku . a . . , .. . 3... . . . 25:. 3......) .. .0 a»? a...“ x . .11 $412.35.... .. u...o.u.31?3 iv... .91) knit. .1 RX“. «35 _ .tl‘lu‘nyl‘ . :9}: (Frf... n); .X... .! .mwvmflhfi .. . til 3 ‘1 : {zfifl h; a.) ‘9' A .AO.‘ ‘- 31., M a}!!! :1 .I’.i..c :71} . I. . {it 3...? .19. t: 9...; A n . . .\‘-‘T (J ‘u .u'no 1......3 .1... .3 lIBRARY Michigan State University This is to certify that the dissertation entitled' EFFICIENCY AND PRODUCTIVITY OF NEPALESE AGRICULTURE presented by NAZMUL CHAUDHURY has been accepted towards fulfillment of the requirements for PhD d . AGRICULTURAL ECONOMICS egree m m @4254 Major prof or Date éflfl/OZJ/Jflo 0 MS U is an Affirmative Action/Equal Opportunity Institution 0-12771 PLACE IN RETURN BOX to remove this checkout from your record. TO AVOID FINES return on or before date due. MAY BE RECALLED with earlier due date if requested. DATE DUE DATE DUE DATE DUE 6/01 cJC|RCIDateDue.p65-p.15 EFFICIENCY AND PRODUCTIVITY or NEPALESE AGRICULTURE By Nazmul Chaudhury A DISSERTATION Submitted to Michigan State University in partial fulfilment of the requirements for the degree of DOCTOR OF PHILOSOPY Department of Agricultural Economics Department of Economics 2001 ABSTRACT EFFICIENCY AND PRODUCTIVITY OF NEPALESE AGRICULTURE By Nazmul Chaudhury In the first chapter, a stochastic production fi'ontier fiamework is used to examine the technical efficiency of rice production for a sample of irrigated farmers in the Rupandehi district of Nepal. Coefficient estimates from the production frontier indicate that: (a) source of irrigation and varietal choice are the two most important factors which enhance rice yields; (b) mid-season water stress and long term non—use of organic fertilizer, are the two primary factors which adversely efl‘ect rice yields. Farm level technical efficiency measures derived from the production frontier model, suggests that on average, rice yields could have potentially been increased by slightly over half a metric ton per hectare, corresponding to a 18% average increase in output, via a more efficient utilization of available resources at the current state of technology. I then explore for the relationship between technical efficiency and two sets of variables: (1) farmers’s grasp of agronomic principles and knowledge; (2) socio-economic environment in which the farmer operates. I am particularly interested in examining how education and land ownership size is related to efficiency, two specific issues which have received considerable attention in the literature. I find a significant relationship between secondary education and efficiency. Average technical inefiiciency in rice production is reduced by 16% in plots farmed by households in which the primary farm manager has completed more than five years of schooling. I also find a significant inverted U-shaped relation between technical inefiiciency and land ownership size (i.e., a significant U-shaped efficiency-size relationship). However, the significance of this efficiency-size relationship appears to be sensitive to model specification/endogeneity bias. In the second chapter, a stochastic production frontier approach embedded in a meta- production function framework is used to : (a) estimate the district level rates of technical change in Nepalese agriculture based upon econometric estimation of the underlying production technology; (b) derive point estimates of district level technical efficiency from parametric estimation of the production technology; and (c) given that I am interested in comparing efficiency levels across districts, I also construct confidence intervals around the time varying technical efficiency estimates, using non-parametric bootstrap methods. When literacy is included in the analysis, there appears to be no significant growth in TFP in the Terai region, while there appears to be a severe decline in TFP growth in the Hill region. Significant negative TFP grth rates in the Hill region might reflect a pernicious decline in the quantity/quality of the natural resource base, however, it is not possible to explicitly examine the interplay between natural resource degradation and agricultural productivity given the data available for this study. This study also highlights the fact that there exists substantial scope for increasing output via a better utilization of existing inputs and technologies in the Terai region. For example, agricultural output in 1991 could have been increased by 40 % in the Terai region via a more eflicient utilization of existing inputs and technologies. There also exists tremendous potential for increasing output in the Hill region, however, this potential is perhaps being squandered due to natural resource degradation. ACKNOWLEDGMENTS I would first and foremost like to express my gratitude and sincere appreciation to my major advisors, Professors John Strauss and Thomas Reardon, for their unwavering support, guidance and encouragement. I would also like to thank the other members of my committee, Professors Peter Schmidt, Scott Swinton and Richard Harwood. I remain indebted to Professor Schmidt for having the patience and generosity to guide me through a challenging tour of the frontiers of ‘stochastic production-frontier’ theory. I am also indebted to Professor Harwood given that I have benefitted enormously from his erudition of the field of sustainable agriculture and extensive knowledge of Nepalese agriculture. Also, Professor Harwood made it financially viable for me to pursue graduate studies at Michigan State University, through his generous support via the MC. Mott Fellowship in Sustainable Agriculture. 1 am grateful to Dr. Peter Hobbs who allowed me to gain full access to the CIMMYT/NARC data set used in the first chapter of this dissertation; I am also indebted to Dr. Hobs for sharing with me his insightfirl reflections on the complex agronomical, economical, political and informal institutional factors which shape agricultural performance in South Asia. I am also grateful for the financial and institutional support provided to me by the International Maize and Wheat Research Institute (CIMMYT), with particular thanks to Dr. Larry Harrington and Dr. Prabhu Pingali. I would also like to thank Mr. Dongol of the Central Bureau of Statistics (Nepal) and Dr. Champak Pokharel of the National Planning Commission (Nepal) for allowing me full access to their data archives - the second chapter iv of this dissertation would not have been possible without their Herculean effort to help me locate rather elusive data. In particular, Mr. Dongol spent an enormous amount of his valuable time and effort to help me - I will forever be grateful for his magnanimity. I am grateful to my dear friends, Janet Owens, Adnan Ozair, Frederik Schlingemann, Jouni Paavola, Jean Bumshin, Jim Myers, Kei Kajisa, Veronique Massanet, Hassen Abdulkerim and Sohail Maklai, for their moral and intellectual support. I am especially grateful to Janet Owens who was always there, particularly in times of extreme duress, to help me retain my humanity and to enjoy the simple joys of life which makes this ephemeral existence an eternal joy. I would also like to especially thank my sister, Akhi, her compassion and concern for the non-Benthamite welfare of both human and non-human life forms, and her vigilance against the hegemony of status quo dogma, has allowed to gain a more holistic appreciation of sustainable development. I thank my mother for sheltering me under her aegis of love and tolerance, and for instilling in me the belief that the essence of religion is love, and the holy book is life itself, with the unfolding chapters of human experiences to help guide the soul. Finally, I would like to thank my father for his intellectual and moral probity which has served as an ideal towards which I shall always strive for. TABLE OF CONTENTS LIST OF TABLES ................................................... vii LIST OF FIGURES ................................................... ix CHAPTER 1 DETERMINANTS OF PRODUCTION EFFICIENCY IN A DYNAMIC AGRICULTURAL REGION OF NEPAL I. Introduction .................................................. 1 II. Agricultural Issues in the Terai ................................... 3 III. Data Section ................................................ 6 IV. Analytical Framework, Empirical Procedures, and Findings ............ 12 EMPIRICAL PROCEDURES AND FINDINGS : ................ 15 DETERMINANTS OF TECHNICAL INEFFICIENCY : ........... 18 V. Conclusion ................................................. 27 BIBLIOGRAPHY .................................................... 42 CHAPTER 2 PRODUCTIVITY GROWTH OF NEPALESE AGRICULTURE I. Introduction ................................................. 49 II. Analytical Framework ........................................ 55 III. Data Section ............................................... 69 IV. Empirical Findings .......................................... 73 Results Without Literacy : Terai Region ........................ 73 Results Without Literacy : Hill Region ......................... 77 Results With Literacy : Terai Region .......................... 80 Results With Literacy : Hill Region ............................ 82 V. Conclusion ................................................. 83 BIBLIOGRAPHY ................................................... 117 vi CHAPTER 1 Table 81 Table S2 Table 1 Table S3 Table 2 CHAPTER 2 Table 81 Table 82 Table 1 Table 2 Table 2.2 : Table 3 Table 4 Table 5 Table 6 Table 7 Table 7.2 : Table 8 Table 9 Table] 0 Table l 1 Table 12 : Within-Estimates of Production Function w/o Literacy - Terai : Within-Estimates of Production Function w/o Literacy - Hill LIST OF TABLES : Changes in Plot level Macro and Micro Nutrients ............ : Summary Statistics of Production Function Variables .......... : OLS and ML estimation results of Production Function ......... : Summary Statistics of Variables used to explore variation in TE . . : OLS estimation results of determinants of variation in TE ....... : Grth Rate of Production Function Variables - Terai ......... : Growth Rate of Production Function Variables - Hill .......... : District level RTC w/o Literacy - Terai ..................... Comparison of RTC to Growth Rates w/o Literacy - Terai ...... : Bootstrap CI for RTC estimates w/o Literacy - Terai .......... : District level TE 1981 w/o Literacy - Terai .................. : District level TE 1991 w/o Literacy - Terai .................. : District level RTC w/o Literacy - Terai ..................... Comparison of RTC to Growth Rates w/o Literacy - Hill ....... : Bootstrap CI for RTC estimates w/o Literacy - Hill .......... : District level TE 1981 w/o Literacy - Hill .................. : District level TE 1991 w/o Literacy - Hill ................... : Within-Estimates of Production Function with Literacy - Terai . . : District level RTC with Literacy - Terai ................... vii 3O 31 32 34 35 86 87 .88 89 9O 91 92 93 .94 95 96 97 98 99 100 101 Table 12.2: Comparison of RTC to Growth Rates with Literacy - Terai . . . . 102 Table 13 : Bootstrap CI for RTC estimates with Literacy - Terai ......... 103 Table 14 : District level TE 1981 with Literacy - Terai ................ 104 Table 15 : District level TE 1991 with Literacy - Terai ................. 105 Table 16 : Within-Estimates of Production Function with Literacy - Hill . . 106 Table 17 : District level RTC with Literacy - Terai .................... 107 Table 17.2: Comparison of RTC to Grth Rates with Literacy - Hill ...... 108 Table 18 : Bootstrap CI for RTC estimates with Literacy - Hill .......... 109 Table 19 : District level TE 1981 with Literacy - Hill ................. 110 Table 20 : District level TE 1991 with Literacy - Hill .................. 111 Table ARI :Districts with Local Agricultural Research Centers - Terai ...... 112 Table AR2zDistricts with Local Agricultural Research Centers - Hill ....... 113 Table 21 : Summary Results .................................... 114 viii CHAPTER 1 Figure 1 : Figure 2 : Figure 3 : Figure 4 : Figure 5 : CHAPTER 2 Figure l : Figure 2 : LIST OF FIGURES Long-Run Average Rice and Wheat Yield for Rupandehi District . . 37 District vs. Sample Rice and Wheat Averages ................. 38 Changes in Rice-Yield by Irrigation status of farmer ............ 39 Changes in Rice fields by FYM application of farmer ......... 40 Changes in Rice Yield by education category of farmer ......... 41 TB and Agricultural Research Centers - Terai ................. 115 TE and Agricultural Research Centers - Hills ................. 116 ix Chapter 1 DETERMINANTS OF PRODUCTION EFFICIENCY IN A DYNAMIC AGRICULTURAL REGION OF NEPAL I. Introduction Nepal, which used to be a food-grain surplus country in the 1970's, has changed to a food grain-deficit country in the 1990's (Banskota 1992). Domestic cereal production and food availability per capita is on a decline in Nepal (Ali, Hobbs and Velasco 1993). Export earnings from both the agricultural and non-agricultural sectors are insufficient to allow Nepal to pursue a food security policy which primarily depends upon cereal imports (ADB 1992). Labor absorbing industrial development has yet to emerge as a significant factor in the Nepalese economy. Thus, Nepal cannot afford to spend its reserves of hard currency on procurement of cereals from the international market. Nepal must rather rely upon strategies which enhance domestic cereal production in an arable land-constrained environment. Currently there is a dearth of empirical studies on the productivity of Nepalese agriculture at either the national, regional or the commodity specific level. The importance of having credible productivity measures of Nepalese agriculture is firrther highlighted by the troubling fact that there is growing concern and evidence that productivity growth in various intensive cropping systems of South Asia is either slowing down or even declining (Hobbs and Morris 1995; Cassman and Pingali 1995; Byerlee 1992). This intensification induced decline in productivity grth could be associated with various factors such as long term changes in soil physical characteristics/decline in soil fertility, ground water depletion and water quality degradation (Pinagli and Rosegrant 1993). Most agricultural productivity studies in South Asia have been at the national level and have focused on macro-level determinants (e. g., investment in agricultural research and extension) of productivity change. It is difficult in national level studies to explicitly control for the effects of micro-level factors (e. g., specific farm level management practices) on agricultural productivity. Thus, regional and cropping system specific studies can provide a platform for more “fine-tuned” productivity measures and allow for exploration of micro-level detemrinants of productivity. Economic efficiency in production is detemrined by the technique of applying inputs and levels of application of inputs. Technical efficiency (TE) reflects the firm’s ability to obtain the maximum possible output fiom a given set of inputs. Allocative efficiency (AE) reflects the ability of the firm to maximize profits, by equating the marginal revenue product with the marginal costs of inputs. These efficiency measures depend upon the factors which determine the firm manager’s technical knowledge, and the socio- economical environment in which the firm manager operates (Kalirajan 1990). While TE measures can be estimated from farm level input-output data, estimation of AE measures require cost/price information. It is not surprising then that TE is the most widely used measure of farm efficiency in the developing country literature (Bravo-Ureta and Evenson 1994), reflecting the fact that farm level cost of production data is relatively more scarce compared to mere physical input-output data. Analytically, estimation of farm level AB is firrther complicated by a host of market failures which plagues the agricultural sector of many developing countries (e. g., AB in production will fail to hold if the farm household faces either a credit/liquidity constraint or an input supply constraint). Thus, while farm level estimation of TE does not (explicitly) require assumptions of market efficiency, most farm level AE measures are obtained . under the restrictive (and probably not realistic) assumption of a perfectly competitive market environment. The focus of this study will be to estimate the technical efficiency of rice production for a sample of farmers in the rice-wheat cropping-system of the Terai region of Nepal. I will also explore for the relationship between farm level technical efficiency and farmer’s technical knowledge and the socio-economic environment in which the farmer operates. This study is thus, both an effort to fill the gap in the productivity literature on Nepalese agriculture, and to add to the growing literature on farm level efficiency of South Asian agriculture‘. Section II of this paper provides brief background information of agricultural issues pertinent to the Terai region of Nepal; Section III briefly discusses the nature of the project which generated the data set used in study; Section IV lays the analytic framework and empirical procedures used in this study, and presents the findings from the analysis ; and Section V highlights the main conclusions of this study and suggests relevant policy implications. II. Agricultural Issues in the Terai Nepal can be divided into three agro-ecological zones: The Terai (lowlands); The Hills (middle mountains); and The Mountains (the High Mountains, and the High Himalayas). The Terai comprises 54% of the cultivated land area and 45% of the population (Banskota 1992). The importance of the Terai stems fi'om the fact that it remains as the only food grain-surplus region in Nepal and is the most favorable area for intensified agriculture. ‘ Estimates of AE could not be conducted due to limited infomation in the data set. 3 Small-holders constitute the majority of farmers in the Terai. Agricultural land is the primary productive resource in rural Nepal, and accounts for more than 88% of the value of farm assets in the Terai (Banskota 1992). However the distribution of this primary means of production is highly skewed, with 16.1 % of the farmers owning 62.8% of the land (Banskota 1992). Land—holding is also the major determinant of access to production credit in the Terai (Yadav, Otsuka and David 1992). Existing government credit programs in Nepal do not appear to be benefitting small farmers, but rather large farmers have been the predominant beneficiaries (Banskota 1992). It is estimated that 77% of formal lending goes to large-scale farmers (Nelson 1987). In a comprehensive analysis of the government’s agricultural credit policy in Nepal, Banskota (1992, pp.70) concludes that “small and marginal farmers have been left out, and access to modern inputs to enhance productivity is denied as they do not have the power to purchase the new technology which is embodied in inputs.” There is a tremendous potential for irrigation in most of the Terai which is endowed with a relatively high water table (combined with monsoon rains which provide a good source for recharge). Groundwater sources of irrigation water can be easily tapped into through small-scale, low-cost irrigation schemes. However the overall irrigation system in Nepal remains underdeveloped and underutilized. Upadhyaya and Thapa (1994) find that irrigation is the most significant determinant of MV seed adoption, intensity of fertilizer use and cropping intensity in Terai (and throughout all major agricultural regions in Nepal). The introduction of wheat in the rice mono-culture has allowed farmers to fit in winter wheat within the traditional rice-based cropping pattern of the Terai. However, delays in rice harvest interfere with the optimal planting date of wheat. The short time available for turnaround for planting wheat often leads to sub-optimal land preparation and use of other inputs. Also, raising two major crops may affect soil quality and increase biotic stress (Hossain 1994). Diagnostic surveys in the rice-wheat cropping system in the Terai have identified soil nutrient deficiencies (associated with nutrient mining) as one of the long term (sustainability) problems common to both rice and wheat, which if unaddressed will increasingly limit rice and wheat yields (Harrington et al. 1993). Plot-level data from long-term experimental stations in the Terai indicates decline in yields of both continuous rice and wheat (even in plots which were treated with recommended applications of inputs) rotations. The fact that both cereals, and different varieties of these cereals “experienced significant declines in yield despite constant levels of management suggests that soil fertility or other as yet unidentified factors were depressing yields” (Hobbs and Morris 1995, pp.31). Ali (1996) examines the efficiency of wheat production drawing upon the same data source used in this study. The author finds that cropping practices such as continuous rice-wheat rotation and discontinuous organic fertilizer application on plots which exhibited both poor soil quality and drainage conditions, resulted in a negative impact on wheat yield. However, both the estimated yield firnction and associated efficiency measures presented in his study could be biased due to the exclusion of labor input in the analysis. III. Data Section A collaborative project has been formed by researchers from the International Maize and Wheat Improvement Center (CIMMYT), the International Rice Research Institute (IRRI), and the national agricultural research systems (NARSs) of Bangladesh, India, Nepal and Pakistan, to examine the issue of sustainablility of the irrigated rice-wheat systems of South Asia. The first country selected for micro-level monitoring was Nepal. The data set used in this study stems from CIMMY T’s monitoring data of plot level practices and resource use in the major rice-wheat regions of Nepal. This study draws upon the survey data of 170 farmers in the Bhairahawa (a major rice-wheat region) study area located in the Rupandehi District of the Terai region of Nepal. The primary objective of the project was to examine if there are signs of an inter- temporal decline in productivity in actual farmer fields. To this end, given budgetary considerations, emphasis was placed on fine-tuning data collection (perhaps too fine-tuned as we shall see) on plots which would most likely exhibit adverse consequences of intensification. Also, “interference” due to jumbling of issues were avoided (e.g., sample consists of farmers who are predominantly owner-operators, even at the plot level, therefore avoiding incorporation of incentive issues associated with various forms of contractual arrangements in land which would complicate the productivity analysis). Farmers in the Rupandehi district are some of the most intensive farmers (in terms of irrigation water use, chemical fertilizer use, adoption of Modern Varieties, etc) in Nepal, benefitting from the marketing channels of the neighboring Indian state of Utter Pradesh. Farmers in the sample were pre-stratified according to whether they were participating in the Bhairahawa Lumbini Groundwater Project, a tubewell irrigation development project funded by the World Bank. The sample included 82 farmers from the groundwater project and 88 farmers fi'om outside the project (referred to as non-project farmers)? Sampling was designed so that all farmers within a stratum would have the same probability of being selected. In both strata, farmers were selected through a multiple-stage sampling. Similar to patterns observed in this region, land holdings are extremely fragmented (while the average land holding size is 2 ha in this sample, the average number of plots is 10). After a particular farm household was selected, the principal farm manager was then asked to identify “an important” (in terms of being a productive plot fi'om the view point of the farmer) rice-wheat plot owned by the household. Most of the plots (90%) were farmed on a continuous rice-wheat rotation - again, plots which most likely would exhibit productivity decline due to soil fatigue or other intensification factors. Plot level data was then collected on farmer’s practices and levels of input use, rice and wheat yields, resource quality, and other related variables. Data collection began in 1990/91 by scientists from the Bhairahawa Wheat Research Farm, CIMMYT, IRRI, and extension workers from the district Agricultural Development Office. The same plots have continued to be monitored since then. Figure 1 shows the long-run trend in both rice and wheat yield at the district level. Figure 2 compares the sample and district averages for both crops. We see that our sample farmers somewhat follow district patterns except for the fact that average yields for both crops are consistently higher in our sample (particularly for rice). 2 Project farmers and non-project farmers do not come from the same village. 7 Our sample is biased towards farmers who use irrigation, and continuously farm on Danda landtype. In this sample, two primary land types are identified, Khala (lower terraces characterized by heavier soils and poor drainage) vs. Danda (upper terraces characterized by lighter soil and few drainage problems, however drought prone). While constructing categories for land type (Danda or Khala) or land ownership holding was fairly straight forward (these categories were static during the sample period), categorizing farmers as “continuous” (plot under a continuous rice-wheat rotation is planted with rice followed by winter wheat during each crop year, and the same rotation is followed every subsequent crop year, and that plot is never allowed to remain fallow) v.s. “non-continuous” (which in our study area is primarily either rice-wheat-mustard or rice- wheat-pulse) ; and ‘irrigated’ v.s. ‘non-irrigated”, was a bit more complicated : Continuous v.3. Non-Continuous : Under ‘ideal’ circumstances a continuous farmer should enter every year under both the rice and wheat sub-sections of the panel, while a ‘non- continuous’ farmer should enter every year in the rice sub-section and every other year in the wheat subsection. However, certain farmers had to keep their plot idle in particular years due to various non-agronomic factors (primarily pre-planting financial constraints). Thus, ‘continuous’ farmers are labeled as those who farm under a continuous rice-wheat regime, leaving the plot fallow only due to non-agronomic reasons; Irrigated v. s. Non-Irrigated : In this study, we categorized a household as “non-irrigated” if the household did not use any source of irrigation water throughout the sample period (1991-1996). On the other hand, we classified a household as “irrigated” if the household irrigated its plot at least once during the sample period. Incidence of irrigation is more prevalent in wheat (which is grown during the dry winter season) There were hardly any farmers in this panel who did not use chemical fertilizers and modern varieties. In the rice sub-section twenty nine percent of the farmers applied nitrogen fertilizer in a “discontinuous” manner (i.e, not every year they appeared in the panel), while 71% of farmers applied nitrogen fertilizer every year that they appeared in the panel (only one farmer never applied any nitrogen fertilizer) ; fifiy three percent of the farmers applied non-organic phosphorus in a discontinuous manner, while 47% of farmers applied phosphorus fertilizer every round of the panel (only five farmers never applied any phosphorus fertilizer) ; Ninety percent of the farmers in the sample used modern rice varieties every year they appeared in the panel, while only 5% never used any modern varieties. In the wheat sub-section thirty one percent of the farmers applied nitrogen fertilizer in a discontinuous manner, while 69% of farmers applied nitrogen fertilizer every year that they appeared in the panel (only two farmers never applied any nitrogen fertilizer) ; thirty three percent of the farmers applied non-organic phosphorus in a discontinuous manner, while 67% of farmers applied phosphorus fertilizer every round of the panel (only one farmer never applied any phosphorus fertilizer) ; unlike the rice sub- section where farmers had intimate detail about every single rice variety that they used, the vast majority of the farmers claimed not to know what type of wheat variety they were using. We do not have sufficient information on other macro nutrient application (e.g., potassium) nor on any micro nutrient application (e. g., zinc). We do have information in certain years regarding use of farm yard manure at the plot level. However, organic fertilizer of such nature makes it difficult to quantify its “composition”. Farm households in this sample region hold two key natural resource assets in their portfolio which they draw upon for agricultural production: soil, and groundwater’ (only irrigated farmers utilize this resource of course). There is negligible soil erosion in this particular region, and it seems unlikely that soil erosion will arise as a major problem in the near future, thus, leaving soil fertility as the key soil related issue. Soil samples were collected fi'om each plot and analyzed during 1991 and 1995. In Table 81 we notice an alarming trend of both macro and especially, micro nutrient depletion (e.g., phosphorus has declined in 92% of the plots, while magnesium has declined in 84% of the plots). Macro nutrient decline in such a short time period comes as a surprise, given that most. farmers use chemical fertilizers. While the implications of macro nutrients deficiency on plant grth has been throughly studied in various agro-ecological zones around the world, we yet do not have a clear understanding between micro nutrient and cereal yield interaction (particularly in this region). In 1991, the average rice yields for irrigated farmers in the sample was 3.3 mt/ha. The average rice yields for the same irrigated farmers in 1996 was close to 4.5 mt/ha. Thus, in a period of five years, average rice yields for irrigated rice cultivated on the same plots, have increased by one mt/ha. In this sample, even non-irrigated farmers, farmers who never apply organic fertilizer (F YM), and farmers without formal education, enjoyed average increases in rice yields over the sample period (see Figure 3 - Figure 5). These yields have occurred without any significant increases of variable inputs (1 do not however, have information on changes in labor input over time), without noticeable 3 The data set does not contain information on actual quantity of water use. Irrigation information appears as number of irrigations given to the plot. Source of irrigations turns out to be a better measure of irrigation use. 10 changes in plant variety adoption, without new types of crop rotations, without adoption of new types of planting/land preparation techniques, nor without adoption of new farming technologies. Average rice yield increase in the same plot without any major changes in inputs/technology, does suggest that it is plausible that farmers in our sample have made efficiency gains in rice production (albeit, we cannot extrapolate from plot level performance to total farm level performance). There are several limitations to this data set. First, it would have been better to have data on each plot owned by the household. This would have allowed us to explicitly examine household level productivity strategies over time, instead of merely examining plot level efliciency tied to certain household characteristics. To examine plot level technical efficiency in this study, I rely upon primal representations of the production technology (e.g, yield firnction). However, we are still left to deal with the problem of endogenity. Inputs used at the farm level are endogenous to the household decision framework, which for rural agricultural households involve simultaneously both consumption and production choices. Then, even if we were lucky enough to have “seperability” (Strauss, Singh and Squire 1986) between household consumption and production decisions, production inputs will still be governed by the matrix of relative prices, degree of risk aversion and other constraints faced by the farm household pursuing various production strategies, making the model nonseperable. I do not have sufficient information to construct robust instruments to address the problem of endogeneity in the primal estimation. On a final note, given that (limited) information on labor use in rice production is available only for the first round of the panel, I estimate TE measures of rice production using data fi'om only the first round of the panel. 11 IV. Analytical Framework, Empirical Procedures, and Findings Working with cross-sectional data limits the possible estimation strategies available to calculate plot level TE (for a thorough review of the issues involved with both cross- section and panel data based estimates of TE via econometric and non-parametric methods, see Fried, Lovell and Schmidt 1993). I will adopt an econometric approach towards estimating plot level TE, and within that framework, I will explore the “stochastic production frontier” approach (Aigner, Lovell and Schmidt 1977; Meeusen and Van' de Broeck 1977; Jondrow et al. 1982). The general idea behind this framework is that each firm faces its own production frontier, and that frontier is randomly determined by a host of stochastic factors outside the control of the firm (Green 1993). However, once the firm-specific production fi'ontier is randomly placed, any deviation from that fi'ontier is due to firm-specific technical inefficiency. A “generic” characterization of our yield fianction within the stochastic frontier framework is as follows: Yr: f(xi»B)+ei = f(xiaB)+vi'ui (El) where, y: crop yield ; x: vector of inputs (including variable inputs and fixed factors) ; [5: vector of unknown parameters; e: error structure; i: firm index. The error term, ei, can be decomposed into two parts: (1) vi, the “familiar” independently and identically distributed (across plots) two sided N(0,o,,z) random variable representing model this-specification, measurement error and random shocks (taking on values which can either be, negative, zero, or positive); and (2) u,, a random variable associated with firm-specific factors which influence whether firm/farmer i attains maximum efficiency of production (taking on values which can either be positive or zero) . This firm-specific time-invariant technical inefficiency parameter is known to the farmer, 12 but not to the analyst. A value of 0 for ui indicates that the farm is operating on its frontier. Any value greater than 0 indicates that the farm is below the fi'ontier, implying that the farm’s practices conditioned by its environment leads it to produce less than the maximum possible output. The random variables v, and ui are assumed to be independent. The compound disturbance in this model (ei = vi + 1.1,), while asymmetrically distributed, can still be estimated from maximum likelihood (ML) estimation of Eq (1). However, before we can proceed with ML estimation, certain assumptions regarding the distributional properties of ui have to be made. One of the most common characterization of ui is to assign it a truncated (halt) normal distribution N(0, of). While TE estimates have been found to be fairly consistent under various specifications of the firnctional form of the production technology, TE estimates are sensitive to the distributional specification of u (Bravo-Ureta and Evenson 1994). Unfortunately, currently there is no satisfactory method for choosing nor testing the ‘validity’ of any distribution (e.g., half normal or gamma distribution). This remains as the primary drawback of estimating TE measures in a stochastic frontier framework using cross-sectional data. Because we do not have plausible instruments in our data set, I also assume that firm-specific level of inefficiency is uncorrelated with the level of inputs (x). Recent developments in this field utilizes panel data to avoid some of the troublesome aspects related with estimating TE measures based upon cross-section data (e. g., Comwell, Schmidt and Sickles 1990). Since I do not have labor data over time, I cannot estimate TE measures using panel data methods. For the half-normally distributed inefficiency term, the log-likelihood firnction is (for details please see Aigner, Lovell and Schmidt 1977) : l3 -&‘1 Kan/3,1,0): -N*ln0' — c+ i [ln where, N : number of observations ; o’ = of + of ; l. = o,, / o, ; and, (.) : (I) is the cdf of the standard normal distribution. I obtain the estimates for o, and o, from the ML estimation of the yield function. To then obtain the farm specific measures of technical inefficiencies (TIE), I use the following formula (Jondrow, Lovell, Materov, and Schmidt 1982): 0’11 ¢(£r*/l/a') 8:51 (1+12)[¢(-£r*/l/0’)- 0' 1 (EB) E[url£i] = where, the pdf and cdf, (p(.) and mam? «mar ram? e. 2:2“. com 000? oomw ooow oomN ooom comm ooov oomv ooom (err/6).) maul earn eBeraAv 41 BIBLIOGRAPHY Aigner, D., Lovell, C.K., and Schmidt, P., 1977; Formulation and Estimation of Stochastic Frontier Production Function Models; Journal of Econometrics 6:21-38. Ali, Mubarik, 1996; Quantifying the socio-economic determinants of sustainable crop production: an application to wheat cultivation in the Terai of Nepal; Agricultural Economics 14: 45-60. Antle, John M., 1983; Sequential Decision Making in Production Models; American Journal of Agricultural Economics 65(2): 282-90. Azhar, R., 1991; Education and technical efficiency during the green revolution in Pakistan; Economic Development and Cultural Change; (39) : 651-665. Banskota, K., 1992; Agriculture and Sustainable Development. In Nepal: Economic policies for sustainable development. Asian Development Bank. Philippines. pp. 51-71. Barker, R., and Herdt, R.W., 1985; The rice economy of Asia. Washington, DC: Resources for the Future. Battese, G.E., TJ. Coelli and TC. Colby, 1989; Estimation of frontier production firnctions and the efficiencies of Indian farms using panel data from ICRISAT’s village level studies; Journal of Quantitative Economics; (5) : 327-348. ----, A. Heshmati and L. Hjalmarsson, 1998; Efficiency of Labor Use in the Swedish Banking Industry : A Stochastic Frontier Approach; Unpublished Paper. Benjamin, D., 1992; Household Composition, Labor Markets, and Labor Demand: Testing for Separation in Agricultural Household Models; Econometrica; Vol(60). Berry, RA, and Cline, W.R., 1979; Agrarian Structure and Productivity in Developing Countries. Johns Hopkins University Press. Baltimore MD. Binswanger, H.P., H. Deininger, G. Feder, 1995; Power, Distortions, Revolt and Reform in Agricultural Land Relations; In: Handbook of Development Economics Vol III; Edited by T.N. Srinivasan and J. Behnnan. ~---, and Sillers, D., 1983; ‘Risk aversion and Credit Constraints in Farmer’s Decision- making: A Reinterpretation’; Journal of Development Studies 20: 5-21. ----, MR. Rosenzweig, 1986; Behavioral and Material Determinants of Production Relations in Agriculture; Journal of Development Studies (22), pp. 503-30. ----, M.R. Rosenzweig, 1993; Wealth, Weather Risk and the Composition and Profitability of Agricultural Investments; Economic Journal; Vol(103). 42 ----, Khandker, S., and Rosenzweig, MR, 1993; How Infiastructure and financial institutions affect agricultural output and investments in India; Journal of Development Economics 41: 337-366. Bravo-Ureta, BE. and Evenson, RE, 1994; Efficiency in agricultural production: the case of the peasant farmers in eastern Paraguay; Agricultural Economics 10: 27 - 38. Byerlee, Derek, 1990; ‘Technical Changes, Productivity, and Sustainability in Irrigated Cropping Systems of South Asia: Emerging Issues in the Post-Green Revolution Era’; CW T Working Paper 90/06; Mexico, D.F.: CIMMYT. ---, 1992;’Technica1 Change, Productivity, and Sustainability in irrigated cropping systems of South Asia: Emerging issues in the post-green revolution era’; Journal of International Development, Vo. 1(4), No.5, 477-496. Cadwell, J.C., 1979; Education as a Factor in Mortality Decline: An Examination of Nigerian Data; Population Studies (33). Comwell, C., Schmidt, P., Sickles, RC, 1990; Production Frontiers with Cross-Sectional and Time-Series Variation in Efficiency Levies; Journal of Econometrics, Vol(46), 185- 200. Cotlear, D., 1986; Farmer Education and farm efficiency in Peru : the role of schooling, extension services and migration. Discussion Paper EDT49; Education and Training Department, World Bank, Washington, DC. Chaudhury, M.K., and L.W. Harrington, "The Rice-Wheat System in Haryana: Input- Output Trends and Sources of Future Productivity Growth", Mexico, D.F.: C.C.S. Haryana Agricultural University Regional Station (Kamal) and CIMMYT, 1993. Chaudhuri, DP, 1979; Education, Innovation and Agricultural Development. Croom Helm; London. Cassman, K.G., and Pingali, PL, 1995; Extrapolating Trends fi'om Long-Term Experiments to Farmers’ Fields: The Case of Irrigated Rice Systems in Asia; In: Agricultural Sustainability: Economic, Environmental and Statistical Considerations. Edited by Vic Barnett, Roger Payne and Roy Steiner; John Wiley & Sons Ltd., England. pp. 63-84. David C. Cristian, and Otsuka, K., 1994; Modern Rice Technology and Income Distribution in Asia. Lynne Rienner Publishers, Inc. USA. CGIAR, 1989; ‘Sustainable agricultural production: imlications for international agricultural research; FAO Res. Technol. Paper 4. 43 Deolalikar, A., 1981; The Inverse Relationship between Productivity and Farm Size: A test using regional data from India; American Journal of Agricultural Economics 63: 275- 279. . Dhawan, B.D., 1977; Tubewell Irrigation in the Gangetic Plains; Economic and Political Weekly 12(39) : A91-A104. Evenson, R., and Rosegrant, M., "Determinants of Productiviy Growth in Asian Agriculuture Past and Future", Paper presented at the 1993 AAEA International Pre- Conference on "Post-Green Revolution Agricultural Development Strategies in the Thirld World: What Next?", 1993. Economic Policies for Sustainable Development, 1992; Asian Development Bank. Philippines. Ehui, SK, and Spencer, D.S.C, 1992; Measuring the sustainability and economic viability of tropical farming systems: a model from sub-Saharan Afiica; Agricultural Economics 9(2): 279-296. Evenson, Robert E., and Rosegrant, Mark W., 1993; ‘Determinants of productivity grth in Asian agriculture past and future’; Paper presented at the 1993 AAEA International Pre-Conference on “Post-Green Revolution Agricultural Development Strategies in the Third World: What Next? Faeth, P., "Evaluating Agricultural Policy And the Sustainabiltiy of Production Systems: An Economic Framework", Journal of Soil and Water Conservation, March-April: 94-99, 1993. The Measurement of Productive Efficiency : Techniques and Applications’ ; edited by: Fried, O.H., Lovell, Knox CA, and Schmidt, Shelton S. ; Oxford University Press. Foster, AD, and Rosenzweig, R., 1996; Technical Change and Human Capital Returns and Investments : Evidence from the Green Revolution; American Economic Review 86(4): 931-953. Fujisaka, S., Harrington, L., and Hobbs, P., 1994; "Rice-Wheat in South Asia: Systems and Long-Tenn Priorities Established Through Diagnostic Research", Agricultural ' Systems, Vol(46), 169-187. Ghose, AK, 1979; Farm Size and Land Productivity in Indian Agriculture: A Reappraisal; Journal of Development Studies 16(1): 27-49. Green, W.H., 1993 ; in ‘The Measurement of Productive Efficiency : Techniques and Applications’ ; edited by: Fried, O.H., Lovell, Knox CA, and Schmidt, Shelton S. ; Oxford University Press. 44 Griffin, K., 1974; The political economy of agrarian change: an essay on the Green Revolution. Cambridge: Harvard University Press. Harrington, L.W., Fujisaka S., Hobbs P.R., Adhikary C., Giri 6.8., and Cassaday K., 1993; ‘Rice-Wheat Cropping Systems in Rupandehi District of the Nepal Terai: Diagnostic Surveys of Farmers’ Practices and Problems, and Needs for Further Research; Mexico, D.F.: CM/IYT, NARC and IRRI. ---, "Indicators and Adoption: economic issues in research on the sustainability of agriculture", Invited Symposim Full Paper, Symposium on Soil Productivity and Nutrient Cycling in Relation to low input Sustainable Agriculture, 15th World Congress of Soil Science, Acapulco, Mexico, 1994 Harwood, RR, 1987; Low Input technologies for sustainable agricultural system. In: V.W. Ruttan and CE. Pray (Eds). Sustainable Agricultural Systems. Westview Press, Boulder, CO/London. Hazel], Y., and Ramasamy, C., 1991. Green Revolution reconsidered: The impact of high yielding rice varieties in South India. Baltimore and London: John Hopkins University Press. Hobbs, P., and Morris, M., 1995; Meeting South Asia’s Future Food Requirements from Rice-Wheat Cropping Systems: Priority Issues Facing Researchers in the Post-Green Revolution era. CIMMYT. Hossain, Mahabub., 1994; ‘Rice-Wheat Production System in Eastern India and Bangladesh: Recent Development and Economic Constraints’; In Sustainability of the Rice-Wheat Production Systems in Asia; Food and Agriculture Organization of the United Nations. ' Hsieh, SC, and Ruttan, V.W., 1967; Environmental, Technological, and Institutional Factors in the Growth of Rice Production: Philipinnes, Thailand, and Taiwan; Food Research Institute Studies 7(3): 307-341. Ishikawa, S., 1967. Economic Development in Asian Perspective. Tokoyo: Kinokuniya. Jamison, D.T., and L]. Lau , 1982; Farmer Education and Farm Efliciency; Johns Hopkins Press, Baltimore. Jondrow, J., Lovell, C.A.K., Materov, 1.8. and Schmidt, P., 1982; On the estimation of technical inefficiency in the stocastic frontier production function model; Journal of Econometrics 19: 233-238. Kalirajan, KR, 1990; On Measuring Economic Efficiency; Journal of Applied Econometrics 5: 75-85. 45 Lockheed, M., D. Jamison and L. Lau, 1981; Farmer education and farm efficiency : a survey; Economic Development and Cultural Change; (29) : 37-76. Lynam, John K. and Herdt, Robert W., 1989; Sense and Sustainability: Sustainability as an objective in International Agricultural Reserach; Agricultural Economics, (3), 381-398. Meeusen, W. And J. Van den Broeck, 1977; Efficiency estimation from Cobb-Douglas production functions with composed error; International Economic Review 18: 43 5-444. Nelson, CC, 1987; Agricultural Price Policy in Nepal; Economic Staff Paper No.35; Asian Development Bank. Nepal: Economic Policies For Sustainable Development, 1992; Asian Development Bank; Philippines. Ostrom, E., 1995; In: Annual World Bank Conference on Development Economics; (Eds) Bruno, M., and Pleskovic, B.; The World Bank; Washington, DC. Pingali, PL, and Binswanger, HP, 1988. Population Density and Farming Systems: The Changing Locus of Innovations and Technical Change. World Population Trends and their Impact on Economic Development pp. 165-186. ----., and Rosegrant, Mark W., 1993; ‘Confronting the environmental consequences of the Green-Revolution in Asia’; Paper presented at the 1993 AAEA International Pre- Conference on “Post-Green Revolution Agricultural Development Strategies in the Third World: What Next? Pudasini, S., 1984; ‘Production and Price Responsiveness of Crops in Nepal’; WGN/ADC Project Research Paper Series No.25, Agricultural Projects Services Center, Nepal. Rice-Wheat Atlas of Nepal; Edited by Huke R., Huke E., and Woodhead T., 1993;1RRI, CIA/HWY T, NARC. Rao, C.H.H., 1975; Technological change and distribution in Indian agriculture. New Delhi: MacMillan Company. Rosenzweig, M., and Wolpin, KL, 1993; Credit Market Constraints, Consumption Smoothing and the Accumulation of Durable Production Assets in Low-Income Countries; Journal of Political Economy; Vol(101). Ruttan, V.W., 1977; The Green Revolution: Seven Generalizations; International Development Review 19(1): 16-23. Roy, R, 1980; Farm Size and Labour Use: A Comment; Economic and Political Weekly 15(39): 1631-1632. 46 ---, 1981; Transitions in Agriculture: Empirical Indicators and Results (evidence from Punjub, India); Journal of Peasant Studies; 8(2): 212-241. Rudra, Ashok, and Sen, AK, 1980; Farm Size and Labor Use : Analysis and Policy; Economic and Political Weekly; Vol(XV), No. 5, 6, 7. Sadoulet, E., and de Janvry, A., 1995. Quantitative Development Policy Analysis. The Johns Hopkins University Press. Baltimore. Schultz, T.P, 1988; Education Investments and Returns; in Chenery and Srinivasan. Schultz, T.W., 1975; Value of the Ability to deal with Disequilibria; Journal of Economic Literature; (13) 827-846. Singh, 1., Squire, L., and Strauss, J., 1986. Agricultural household models: extensions, applications and policy. Baltimore: John Hopkins University Press. ---, 1990; The Great Ascent : The Rural Poor in South Asia; Johns Hopkins Press, Baltimore. Strauss, J., 1990; Households, Communities, and Preschool Children’s Nutritional Outcomes : Evidence from Rural Cote d’Ivoire; Economic Development and Cultural Change; (38). ---, and Thomas, D., 1995; Human Resources : Empirical Modeling of Household and Family Decisions; In: Handbook of Development Economics, vol. 3A; (Eds) Behrman, J ., and Srinivasan, T.N.; North Holland Press, Amsterdam. Timmer, CR, 1988; The Agricultural Transformation; In: Handbook of Development Economics, vol. 1; (Eds) Chenery, H., and Srinivasan, T.N.; North Holland Press, Amsterdam. Upadhyaya, H.K., and Thapa, GB, 1994; Modern Variety Adoption, Wage Differentials, and Income Distribution in Nepal; In: Modern Rice Technology and Income Distribution in Asia. (Eds) Cristina, CD, and Otsuka, K.; Lynne Rienner Publishers, Inc. Van Zyle, Johan, Binswanger, H., and Colin,T., 1995; The Relationship bewtween Farm Size and Efficiency in South African Agriculture; Policy Research Working Paper 1548; The World Bank. 47 Whitaker, M. and S. Lalitha. 1993. Quantifying the relative productivity and sustainability of alternative cropping systems; Resource Management Program Economics Group Progress Report 115, ICRISAT. 48 Chapter 2 PRODUCTIVITY GROWTH OF NEPALESE AGRICULTURE I. Introduction The neoclassical grth models pioneered by Abramovitz (1956), Swan (1956), Solow (1957), Fabricant (1959), and Kendrick (1961), highlighted the role of (exogenous) technological change in driving macro economic growth. The “Solow residuals” - the residual grth in output not accounted for by the grth in factor inputs, were supposed to measure the contribution of technological progress (also often referred to as “Total Factor Productivity” growth). However, long before the emergence of “new grth theory” in macro economies which began to emphasize the role of investments in human capital and research-and-development (R&D) as endogenous drivers behind technological change (e. g., Romer 1986, 1987, 1990; Grossman and Helpman 1991; Aghion and Howitt 1992), Griliches’ seminal empirical analysis on the measurement and explanation of productivity grth in United States agriculture, highlighted the role of education and public expenditures on agricultural research and extension (R&E), as the principle drivers of grth in the agricultural sector (e.g., Griliches 1963; 1964;]967). Building upon Griliches’ work, various researchers have explored the determinants of productivity grth in the context of international agricultural development (e.g., Hayami and Ruttan 197], 1985; Evenson and Kislev 1975, Boyce and Evenson 1975, Evenson and McKinsey 1991; Binswanger and Ruttan 1978; Mundlak and Hellinghausen 1982; Lau and Yotopoulos 1989). Discourse on how to measure productivity and exploration of the determinants of productivity growth, continues to be an important agenda in international agricultural 49 research. Particularly within a developing country context, productivity increasing technological change in agriculture has been recognized as one of the principal catalysts of growth. Ideally, the positive impacts of increasing productivity comes about through an interplay of boosting output, increasing demand for agricultural labor, lowering food prices, improving rural incomes, stimulating rural non-farm employment, and increasing purchasing power of poor consumers. Thus, the linkages between increasing agricultural productivity and its multipliers, helps to initiate the economic transformation fi'om a predominantly agrarian to a primarily industrial and service-oriented economy (Tirnmer 1988;Me11or 1995). The agenda of this study is to examine the productivity of Nepalese agriculture at the aggregate district (agro-ecological) level. Nation level analysis is useful in the sense that it provides a general picture of overall agricultural performance. However, given that in this study, I am relying upon estimates based upon primal representation of the underlying production technology, it is often difficult to estimate “individual country production firnctions from individual country data The first difficulty is insufficient variation of the quantities of inputs, due to multicollinearity ..., or due to restricted range of variations ..., or due to approximate constancy of factor ratios resulting fiom approximate constancy of relative factor prices Insufficient variation in the data due to any one of the above-mentioned reasons results in imprecision, unreliability, and possible under identification of the estimated parameters of the production function .. The second difficulty is the general inability of separate identification of the level of technological change of the production function of an individual country and its biases or the degree of returns of scale from time-series data on output and inputs of that country alone (Lau and 50 Yotopoulous 1989 , p.242). Thus, not only can district level analysis differentiated by agro-ecological zones provide a sharper picture of agricultural performance, it also avoids some of the pitfalls mentioned above. Currently there is a dearth of empirical studies on the productivity of Nepalese agriculture at either the national, regional or commodity specific level. For example, an unpublished M.S. thesis in 1973 was the first and subsequently for 26 years, has been the only study in which someone attempted to estimate the Total Factor Productivity (TFP) grth of Nepalese agriculture (Shah 1973). The Nepalese economy is predominantly agrarian with more than 90% of the population living in rural areas (and about 80% of the active labor force employed in agriculture). Unfortunately the performance of the agricultural sector over the last few decades has been dismal, and “can generally be summarized as stagnant, with increasing population pressure leading towards fragmentation of land, lower labor productivity and further poverty” (Pokharel 1993, p.43). Nepal, which used to be a food-grain surplus country in the 1970's, has changed to a food grain-deficit country in the 1990's (Banskota 1992). Domestic cereal production and food availability per capita is on a decline in Nepal (Ali, Hobbs and Velasco 1993). Export earnings from both the agricultural and non-agricultural sectors are insufficient to allow Nepal to pursue a food security policy which primarily depends upon cereal imports (ADB 1992). Labor absorbing industrial development has yet to emerge as a significant factor in the Nepalese economy. However, currently only the agricultural sector has the size and the multipliers necessary to stimulate broad based economic growth. Thus, Nepal cannot afford to spend its reserves of hard currency on procurement of cereals from 51 the international market. Nepal must rather rely upon strategies which enhance domestic cereal production in an arable land-constrained environment. Thus, it is imperative that we analyze prospects for productivity grth in Nepalese agriculture. 1 am aware of the apprehensions Griliches expressed more than three decades ago regarding ‘mere’ estimation of technical change - “Identification of measured grth in total factor productivity .. provides methods for measuring technical change, but provides no genuine explanation of the underlying changes in real output and input. Simply relabeling these changes as Technical Progress or Advances of Knowledge leaves the problem of explaining growth in total output unsolved.” (Griliches 1967, p.309). However, given the paucity of sound empirical diagnosis on the state of Nepalese agriculture, this study provides a necessary starting point from which to launch a systematic investigation of the productivity of Nepalese agriculture. 1 Changes in productivity grth reflect changes in scale, technology, human capital, quantity and quality of the natural resource base, and efficiency. Economic efliciency in production is determined by the technique of applying inputs and levels of application of inputs. Technical efficiency (TE) reflects the ability to obtain the maximum possible output from a given set of inputs. This is the most widely used measure of the efliciency of a production unit. Allocative efficiency (AE) reflects the ability to maximize profits, by equating the marginal revenue product with the marginal costs of inputs. While TE measures can be estimated from (primal) input-output data, estimation of AE measures requires (dual) cost/price information. It is not surprising then that TB is the most widely used measure of efficiency in the developing country literature (Bravo-Ureta and Evenson 1994), reflecting the fact that cost of production data is relatively more scarce compared 52 to physical input-output data. Analytically, estimation of AB is further complicated by a host of market failures which plagues the agricultural sector of many developing countries (e. g., AB in production will fail to hold if farmers faces either a credit/liquidity constraint or an input supply constraint). Thus, while estimation of TE does not (explicitly) require assumptions of market efficiency, most AE measures are obtained under the restrictive (and probably unrealistic) assumption of a perfectly competitive market environment. Most estimates of technical change or TFP are based upon non-parametric growth accounting methods embedded in the neoclassical framework, characterized by competitive equilibrium and constant return to scales (which imply that payments to . factors should exhaust total product). The grth accounting approach is as follows: (a) detail accounts of all pertinent outputs and inputs of the production process are compiled; (b) these outputs and inputs are aggregated using various types of indexing procedures, and these indexes are used to calculate a TFP index. The various indexing procedures reflect economic assumptions of the underlying production technology and production environment. The basic idea is that if ‘technological’ change occurs, then payments to factors would not exhaust total product, and there would remain a residual output not accounted for by increases in total factor input (Capalbo and Antle 1988). This has been by far the most common representation of TFP. However, the principal drawback of the grth accounting method is that it is relatively data-intensive requiring extensive factor price information. As Block (1993) points out, the data-intensity of grth accounting methods makes it an impractical tool for examining the productivity in the agricultural sector of most Afiican countries. Similarly most productivity studies of South Asian agriculture have been carried out using Indian and Pakistani data - countries like Nepal 53 lack the institutional capacity to collect pertinent detailed data on a systematic basis in order to carry out most growth accounting exercises. Thus, in such data-constrained cases, parametric approaches which primarily draw upon physical input-output data, are more appropriate. While the growth accounting procedure makes strong assumptions about the underlying production technology (e.g., constant returns to scale) and production environment (e. g., perfect competition), the econometric approach makes an equally strong assumption - that the nature of technological change can be represented as a function of time'. Specifically, in this study, I will: (a) estimate the district level rates of technical change in Nepalese agriculture based upon parametric estimation of the underlying production technology within the “meta-production function” framework; (b) derive point estimates of district level technical efficiency from econometric estimation of the production technology within the ‘stochastic production frontier framework’; and (c) given that I am interested in comparing efficiency levels across districts, I also construct confidence intervals around the time varying technical efficiency estimates, using non- parametric bootstrap methods. This study, is thus, both an effort to fill the gap in the productivity literature on Nepalese agriculture, and to add to the growing literature on the efficiency of South Asian agriculture. Section II of this paper lays the analytical framework and empirical procedures used to estimate district level technical change and efficiency; Section 1H briefly discusses the district level data sources; Section IV presents the empirical findings from the analysis; '° Technological change is synonymous to productivity change under the assumption that production is efficient or that the degree of inefficiency is constant. 54 and Section V highlights the main conclusions (and shortcomings) of this study, suggests direction of further research, and discusses relevant policy implications. II. Analytical Framework To estimate district level rates of technical change (RTC), I employ a “Meta- Production Function” approach as originally forwarded by Hayami (1969) and Hayami and Ruttan (1970, 1985), and extended by Lau and Yotopoulos (1989) and Lau et al. (1993). Under a meta-production function framework, it is assumed that all production units have access to the same underlying technology. As I will show, there is ‘convergence’ between the stochastic production frontier approach (Aigner, Lovell and Schmidt 1977; Meeusen and Van de Broeck 1977; Jondrow et al. 1982) and the resulting estimation framework of our production technology. District level time-varying TE estimates will be estimated following the approach of Schmidt and Sickles (1984) and Comwell, Schmidt and Sickles (1990); bootstrap confidence intervals for the district level TE estimates will be constructed along the lines of Schmidt and Kim (1999). Following Lau et al. (1993), I assume that all districts within a given agro- ecological region have access to the same technology, i.e., an underlying aggregate production function F(.), a meta-production function. However, different districts operate may operate on different parts of the meta-production filnction. These differences arise fi'om possible differences in efliciencies of production, differences in quality of inputs (man-made and natural resources), or due to various measurement errors. Despite these differences, the measured outputs and inputs of the different states may be converted into standardized “efficiency-equivalent” units of outputs and inputs: w, = F(X* ii“ 13,) v j=1,...,J;i=1,...,N;t=1,..T (1) 55 where, Y is output; Xs are “conventional” inputs indexed by j (J inputs); E is education; district index i (N districts); and time index t (T time periods). The implicit assumption is that the meta-production function itself does not depend on i but may depend on t. The “efficiency-equivalent” quantities of outputs and inputs are off course are not directly observable. They are however, assumed to be linked to the measured quantities of outputs and inputs, through possibly time-varying and district-and-commodity-specific augmentation factors: Y2: = Ad(t)Ya (2) X2“ = A J-,,(t)X,-,, V j = 1,...,J (3) B‘a. = E... + AN) (4) There are many reasons why these commodity augmenting factors are not likely to be identical across districts. Examples include differences in climate, topography, natural resources and infi'astructure; differences in definitions and measurements; and differences in the efficiencies of production. For empirical implementation, the commodity augmentation factors for output and all inputs besides education are assumed to have a constant exponential form with respect to time. The augmentation factor for education is assumed to have the linear form with respect to time. Thus, Y2: = Aoi(t)Yit = Ana 3X13 (Coi’ 0 Yr: (5) X1}, = A J.,,(t)x,, = Ai exp (Cl; 0 x,, v j = 1,..,J (6) Eli = Am“) '1' E11 = An. '1' cm 1% +151: (7) where, A’s are the augmentation level parameters and C’s are the augmentation rate parameters (assumed to be constants). 56 For this study, I assume that the meta-production function (1), takes on a Cobb- Douglas functional form”: J lnY.lr= lnYo+ZajlnX',-n+a£.u (8) 2-1 By substituting equations (5) through (7) into the Cobb-Douglas form, and rearranging terms, we get: J J J 1n Y. = 1n Y0+ Z arm/13 +aEEn + {- ln A.+ 2 ajlnAj} + {—C..- + Z 0.} *r (9) 121 j: l j: 1 We can then rewrite (9) as: J 1111,11: 1nY0+Zaj1anit+aEEit+A.i+C.i*t (10) i=1 In order to estimate equation (10) within a statistical framework, I add an independently and identically distributed (lid) two sided N(0,o,’) stochastic disturbance term 85,, having identical variance and assume that it is uncorrelated across districts: J llerr= ll‘lYo-l' Z a/lanil+ aEEit‘l' A.l+ C.i*l+ 6‘11 (11) i=1 " Given the limits of the panel data and the number of inputs I include in the estimation, I cannot use a more flexible functional form such as a transcendental logarithmic function (Christensen et a1. 1973). 1 also do not use a Cobb-Douglas plus (log) interactions of selected inputs due to computational limitations and generally weak results. I shall bring up this issue again in section V. 57 Thus, using the meta production function framework with a Cobb-Douglas specification, district level time-invariant heterogeneity, A,- ,and district level time-varying heterogeneity, Ci , enter the estimation in a linearly separable fashion. District level rate of technical progress/RTC, is captured by the district-specific heterogeneity term interacted with the time trend, Ci . The specification of equation (11) does not allow us to estimate separate commodity-specific rates of technical change (Cji V j = 1,..,J). However, given that in this study I am primarily interested in estimating overall rates of technical change at the district level, the specification of equation (11) will suffice. The specification of equation (11) is similar to the Fixed-Effects Panel data framework regarding the estimation of technical (in)efflciency of production. A Cobb- Douglas specification within a stochastic frontier fiamework is as follows: J lnYl. = 1n Y.+ Z a,lnX,-.. + aeEn . e. - TIE” (12) I" where, TIE, (20) represents time-varying inefficiency (i.e., firm-district technical inefficiency is allowed to change over time). We can rewrite equation (12) as: J - 1n I," = an '1' Z a; In int '1' aEErr + 8t! (13) j=1 where, 0,, = (lnYo - TIE“); We then represent the time-varying firm-district technical inefficiency effect as an explicit firnction of time: 0,, = 0li + 02ft ; we can then rewrite equation (13) as: 58 J In Yr: = z a; 1n X311 + aEErr + 9,, + 62, * l + 8a (14) i=1 The core idea behind the stochastic frontier framework is the same, regardless of cross-section or panel data applications Let us look at the last three terms of equation (14). The last term, 8,, is the “familiar” iid two sided N(0,o,’) random variable representing model this-specification, and random shocks (taking on values which can either be, negative, zero, or positive), while the TIE parameters, 0,, and 02,. represent firm- district specific factors which influence whether firm-district i attains maximum efficiency of production (taking on values which can either be positive or zero). At any given time period, a value of 0 for TIE indicates that the firm-district is operating on its fiontier, and any value greater than 0 indicates that the firm-district is below the frontier (under the assumption that all districts are bounded by the same frontier - if that assumption does not hold, then we cannot separate differences across districts from TIE within a district). By construction of the model, the TIE parameters, 0,, and 02,. are correlated with the X5, thus, suggesting a Fixed-Effects (FE) specification as advanced by Schmidt and Sickles (1984), and extended by Comwell, Schmidt and Sickles (1990), henceforth referred to as C38 1990. Unlike the Random-Effects characterization of this problem which ofien requires strong distributional assumptions about the nature of the TIE parameters, the only further assumption I need to make is that of ‘Strict Exogeneity’(Wooldridge 1996): E(8II|91I , 92i , lnXlil,.e.,lnX1iT,eee, lnXJil,.ee,lnx1iT’ Eil,...,EiT) : O (15) 59 When the strict exogeneity condition holds, X,,, V t = 1,..,T (and V j = 1,..,J) are strictly exogenous conditional upon the two unobserved (or latent) effects. This follows from the conditional mean specification: E(1nY,,|01, , 02,, lnX,,,,...,lnX,,,,..., lnXm,...,lnX,,T, E,,,...,E,r ) = qunxi+01,+02,*t (15.1) Given the assumption of strict exogeneity”, ignoring issues of efficiency for the moment, the parameter estimates of the production function (a, V j = 1,..,J) in equation (1 1)/(14) can be obtained through a number of econometric techniques (Green 1990; Wooldridge 1996). The specification of equation (1])/(14) is no more than that of the standard unobserved fixed-effects model augmented by a district-specific trend as an additional source of heterogeneity - a ‘random grth model’ (Heckman and Hotz 1988). Whenever the dependent variable is expressed in natural logs, the 02, parameter can be viewed as the average growth rate over a period (holding the explanatory variables fixed). Possible estimation strategies include: simple least squares including district dummies and district dummies interacted with a time trend; Second-Differencing and then applying least squares; First-Differencing and then standard ‘within’ FE estimation (for the nuances pertaining to the consistency of the estimates and asymptotic properties implied by these different techniques, please see Wooldridge 1996). '2 If the strict exogeneity assumption fails to hold, then this problem can still be estimated using non- linear instrumental variable techniques, under the assumption of ‘Weak Exogeneity’or ‘Sequential Moment Restrictions’: E(e,,|01, , 02, , lnX,,,,lnX,,T,,'...,1nX,,1 ,..., 1nX,,,,lnX,,T_,,...,1nX,,,, E,T,E,T_,,...,E,, ) = 0 , t = 1,..,T For this study I will use the efficient instrumental variables approach advanced by C88 1990 as a comprehensive approach towards estimating panel data models with heterogeneity in slopes as well as in intercepts. C88 1990 specifies a systematic fiamework in which to obtain consistent estimates of both the production function parameters, and the time-varying district level productivity/(in)efficiency". Following CCS 1990, I rewrite the data-intensive representation of equation (1 l) in matrix notation as follows: Y = lnYo + X13 + Qu + a, (16) where: Y is the (NT x 1) output vector of stacked 1n Yit (stacked by each N which is observed T times); lnY0 is (NT x 1) vector of Is; X is the corresponding (NT x K) input matrix following the stacking order of Y - now including E,,; B is a (K x 1) vector of parameters to be estimated; Q is the (NT x NL) block-diagonal matrix (with e on the off- diagonals) representing district level time-invariant and time-varying heterogeneity”; and, u is the (N *L x 1) parameter vector of 05 (L = 2 in our setting) - for example, the first 2 rows of u would be 011 and 02,, and the last two rows would be 0m and 021., , respectively. Given that I will be dealing with the case in which L sT, Q will have full column rank, and thus, 0 will be identified. Let PQ = Q(Q’Q)"Q’ be the projection onto the column space of Q (NT x NT). Let MQ = ( IN.T - PQ ) be the projection onto the null space of Q (NT x NT). The consistent “within” estimator is given by: ,0», = (X’MQxy' X’MQY (17) '3 While instead of specifying the firm-district level effect as 01,, = 01i + 022,t + 03,t2 as in CSS 1990, in this study we end up with only a linear time effect. "' For example, the “first block” would be (there would be N such blocks): T rows of Is in the first column; T rows of the time-trend (1 to T) in the second column. 61 The within estimator is an instrumental variable (IV) estimator, with instruments MQ; note, that since ManYo = 0, the constant intercept term of the production firnction cannot be consistently estimated. Similar to the standard FE within model (i.e., when 02, = 0), equation (16) can be transformed by MQ and the parameter estimates of the production firnction can be obtained via least square regression of MQY on MQX. I can then estimate district level technical (in)efficiency measures using the within residuals (éw = Y - Xflw) following CSS 1990; Schmidt and Sickles (1984). For each district, we regress the T district residuals on a constant and a time-trend (i.e., a least square regression with T-L degrees of freedom), to get 0 1:62: (which are consistent V i and t, as T - co). Once the @1552: estimates have been obtained (e.g., either through ‘two-step’ CSS 1990 method, or through ‘one-step’ OLS regression of output on inputs and district level dummies and district level dummies interacted with time), for each time period, we can evaluate (HAL-z + 632:: * t) V i = 1,..,N. Then we can define: éit = max,=, ..... N(élir+é2ir*l) (18) For each time period, we can obtain the technical inefficiency estimates for each district as follows: I‘ll-l = 0.. - (91,, 02.117) (19) For any given time period, the district with the lowest value of T11: can be thought of as the best district in the sample (with a value of 0 indicating that the 62 production in the district is occurring on it’s frontier). Thus, T10 is an estimate of relative rather than absolute inefficiency. Given that the production technology follows a logarithmic specification, the technical efficiency estimate, TE,” for each time period (and for each district) can be expressed as: TE" = exp‘ T1”) . (20) Thus, technical efficiency estimates are also expressed “relative”to the most efficient (best) district (with a value of 1 indicating that the production in the district is occurring on it’s frontier). With N fixed, as T - co, 91,62 , are consistent estimates of 01 and 02 (V i and t), and similarly I7" is a consistent estimate of 0., (V i and t). However, given that in this study 1 am using a sample with a relatively small T(=]1), flu may be biased upwards - the “max” operator in equation (18) induces upward bias, since the largest (6111+ 02n*l)is more likely to contain positive estimation error than negative error. This bias is large when N is large (relative to T), and when (510+ éZit*t)IS measured imprecisely. Upward bias in (9111+ éer*l)induces an upward bias in T70 , and thus a downward bias in TE: - thus, efficiency would be underestimated given that the level of the fiontier has been overestimated. For a rigorous exposition of the asymptotic properties of these type of models, please see Park and Simar (1994) 63 Given that I have not made any distributional assumptions regarding the nature of the time-invariant and time-varying heterogeneity (or technical inefficiency), at this juncture I only have ‘point estimates’ of flit and T Err . I cannot rank (in)efficiency levels across firms-districts with statistical precision. The overwhelming majority of past empirical studies of efficiency have tended to overlook this issue. We can use (non- parametric) bootstrapping to construct confidence intervals both I72: and TE". (Simar 1992; Hall, Hardle and Simar 1993, 1995; Kim and Schmidt 1999). The bootstrap method was introduced in 1979 as a simulation-based method for estimating the standard error of A any given estimator, 6 , regardless of the mathematic complication of the estimator (the following section closely follows Efron and Tibshirani 1993). The core of this technique rests upon the notion of a bootstrap sample. For example, let X = (Xl,...,xn) be an observed random sample from an unknown probability distribution F, with a corresponding estimator 19 = S (X ) , and unknown standard error 56r(é). Letfi be the empirical distribution, which places a probability of 1/ n on each of the observed values . A bootstrap sample, X . , is defined to be a random sample of size n drawn from F . Thus, while X represents the actual data set, X I , represents a resampled version of X - the bootstrap data points(x‘l,...,x‘n) are a random sample of size n drawn with replacement from the population of n objects (Xl,...,xn) . Therefore, the bootstrap data ‘ . . . set (x 1,...,xtn)C0n51SlS of the same members of the onglnal data set (xl,...,xn) , some (,4 appearing zero times, some appearing once, and some appearing more than once. The corresponding bootstrap replication of the estimator is, 9. = S (X t). The bootstrap estimate of the standard error of the estimator/statistic ’ 9 , is a plug-in estimate that uses the empirical distribution function}? instead of the unknown distribution F . The following is the algorithm for estimating non-parametric (since the estimate is based on the non-parametric estimate of the population) standard errors of any estimator from an observed random sample X : (1) Select B independent bootstrap samples X ”,...,X .8 , each of size n with values drawn with replacement from X . (2) Evaluate the bootstrap replication corresponding to each bootstrap sample, é'(b)= S(X"’)Vb =1,...,B (3) Approximate ser(9) by the sample standard deviation of the B replications: B M = 1): Iran). é(.)]2/(B- 1) , B where, 9(.) = Z 9.(b)/ B ; and asymptotically, lim 33' = sci . b=1 B-) 00 65 Now turning to the specifics of this study, I will outline the bootstrap procedure on how to simulate the standard errors and construct confidence intervals for the estimate13 for which I am primarily interested in, T E: . Given that the within estimation described above is for all practical purposes analogous to doing least squares with district dummies and district dummies interacted with time - “the elaborate matrix results in their (CSS 1990) paper notwithstanding, for a moderately sized data set, the most expeditious way to handle this model is brute force, OLS” (Green 1990, p. 113), I will follow Green’s advice when running the bootstrap simulation. Thus, 911,921, is estimated in a ‘one-step’ procedure from the least square regression of output on inputs plus district dummies and district dummies interacted with time, i.e., OLS regression of equation (14). The bootstrap samples will then be drawn by resampling the OLS residuals. For the first iteration: (1) I resample the original OLS residuals; (2) generate a corresponding pseudo data set Y (I) (or a resampled Y) using the parameter estimates of the inputs and 911,921, Y(1)=X,90LS +91i+92i*t+é(1)0LS ; (3) redo the OLS estimation using original X and resampled Y (I), to get 9(1)0Ls,91r(1) ,921“) ;(4) use 91r(l),921(1) to estimate TI“’..,TE“’.-.(Vi,r), I repeat this procedure B(=2000 in this study) times to obtain '5 Confidence intervals for 01 and 02 can of course be constructed via standard parametric techniques given that we already have the standard errors for these estimates, however, in this study I will also use bootstrapping methods to construct confidence intervals for these estimates. 66 bootstrap flammfllr‘wflzw),TIu‘b),TEu‘b). Proof of the validity of applying bootstrapping techniques for this problem is given by Hall, Hardle and Simar (1995). The percentile bootstrap is the simplest bootstrap technique for constructing confidence intervals. Let G be the cumulative distribution firnction (cdf) of the B bootstrap replicates, 9”). The 1-2a percentile interval is defined by the a and 1-0. A percentiles of G , with the lower and upper bound of the estimator given by: [9%ro,9°/.up] = [G'l(a),G—l(l - (1)]. Since by definition: G"(a) = 9"“), which represents the 100rrth percentile of the bootstrap distribution, we can write the percentile interval as: [é%10,é%up] = [é‘(a)’é*(l-a)] For example, for a 90% confidence interval (CI), with B = 2000 and o. = 0.05, the percentile interval is the interval ranging from the 100'" to the 1900* ordered values of the 2000 bootstrap replicates. While the percentile technique is relatively simple, it might be an inaccurate method for relatively small time periods. The bias-corrected and accelerated (BCA) technique, is considered to be a substantial improvement over the percentile method in both theory and practice (for details please see Efron and Tibshirani 1993). The plug-in estimator tends to introduce downward bias in the bootstrap replicator. The BCA method automatically corrects for this bias. The BCA 1-2a CI is given by: 67 [9%10, 9%up] = [9am I) ,9‘(a2)], where: 20 + 2‘“) 20 + 20'“) 1— am 299)} i “2 = ‘1’ {2” 1- 0(2.+ Iva-9)} a]: ¢{20+ where, <1>(.) Is the standard normal cdf and 2‘“) is the 100ath percentile point of <1>(.). For example, 2‘09”: 1.645, and d>(l.645) = 0.95. Note that if 9 = 20 = O , then a] = a , and 0.2 = (l-a), thus, I revert back to the percentile CI specification. The value of the bias correction 20 is obtained fiom evaluating inverse standard normal cdf at the proportion of A bootstrap replications which are less than the original point estimate 9: 20 =