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Xerox University Microfilms 300 North Zeeb Road Ann Arbor, Michigan 4B10G 73-20,399 SETTHAWONG, Phisit , 1941)AN ECONOMETRIC ANALYSIS Or ENGEL CURVES: ON M.S.U. CONSUMER PANEL DATA. BASED Michigan State University, Ph.D., 1973 Economics, general University Microfilms, A XEROX Company , A nn Arbor, M ichigan AN ECONOMETRIC ANALYSIS B A S E D ON M.S.U. OF CONSUMER ENGEL CURVES: PANEL DATA By Phisit Sotthawong A THESIS S u b m i t t e d to M i c hi gan State U n i v e r s i t y in p a r t i a l f u l f i l l m e n t o f t h e r e q u i r e m e n t s f or the d e g r e e of DOCTOR OF Department PHILOSOPHY of 1973 Economics ABSTRACT AN ECONOMETRIC ANALYSIS BASED ON M.S.U. OF ENGEL CURVES: CONSUMER PANEL DATA By Phisit In the p r e s e n t M.S .U . C o n s u m e r Pan el curves, (2) utility functions modities fruit s ; modify under curves, and the Enge l dairy se t out forms the E n g e l double-log studies showed "goodness food, highest the income for we r e (3) the selected forms. The that n o functional fit" to semi-log elasticity the Engel com­ a n d o i ls ; on th e f o od s. tr u e func­ linear, thirteen cross- form un iformly the o b s e r v a t i o n s . form d i d the and eggs. studies They w e r e the The fats f i sh , for of approximate five c o m p o s i t e curves. of use curves. products; sectional sectional the analyze cro ss and give (1) thirteen semi-log, composite to poultry, mathematical each made meat, Three a better author and were gave the 1958 Engel studies were curves form of d a t a of by m e a n s of Engel tional stud y , the vegetables; First, Setthawong For consistently estimates which were Phisit widely log different forms. for e a c h log Surprisingly, composite forms were cross from those very sectional estimates As double-log forms were the income based the on .7052, .2989, .1885, and estimates were forms, of the log, linear, and forms w e r e c o n s u m p t i o n was the The of .0938, the i n c o m e semi-log, and respec­ linear, .2209, estimates The and respectively. for f r u i t s forms figures were .4768, based on the semi-log, As forms were Generally, predominantly the c r o s s modified for estimates the on linear, etc., b a s e d on the .22 59 , and the semi­ and income elasticity b a s e d on e i t h e r inelastic: the and Engel's negative nonlinear forms func­ law of income were infrequent. sectional Engel meat, .5428, foods Elastic relatively pooled. and linear, income elasticity found, were semi-log, the confirmed. Secondly, the of five c o m p o s i t e were on mean based they income e l a s t i c i t y and d o u b l e - l o g elasticity estimates but the respectively. double-log for t h e of .2091, elasticity respectively. estimates the respectively. income the t h i r t e e n the m e a n linear, .3388, all .1009, elasticity for v e g e t a b l e s mean tional and .1988 double-log .2353, .5217, semi-log, over based on double­ l i n e a r and d o u b l e ­ the .2604, based linear a n d on a nd o i l s , estimates the elasticity estimates The m ean forms were fat s on income equal products elasticity of based st u d i e s . for The m e a n the nearly for d a i r y and d o u b l e - l o g tively. food based Setthawong and curves time s e r i e s d a t a were formulated for Phisit estimating composite order foods. Engel panel actual the income reported food p r i c e first order were for m e a t , the income and oils; .0928, price mates, etc. After the sistency of by the highly signs of of the p a n e l the dairy meat, data was the to but for were As -1.4543, fats and products; et c . the food s close .6966 on Based on autoregressive etc., these combined based composite products; and the to r e p r e s e n t respectively. th e first for v e g e t a b l e s ; income they c o n f i r m e d the form o f positive, they were and th e fiv e a n d meat, for as disturbances, for d a i r y .1472, -.3580 of products; .6629 estimates, and the five households. scheme for the indices, used panel estimates and price were f or selected functional eliminating vegetables; .5031 effects, fats .0170, f o r the -1.5712, fats and respectively. price elasticity studies were demand theorem. probably the ma in esti­ highly The con­ reason f or success. Lastly, evidence tions prices, vegetables; results as M.S.U. fruits; .0533, -.7424, the The for d a i r y elasticity successful this .8284 fruits; Regarding true They were for frui t s; the coefficients elasticity oils; food .7100 .1808, -.8158, fo r elasticities form was autoregressive t h a n one: oils; linear faced estimated. less and price curves. autoregressive and The approximation modified the both Setthawong on based on Wald's theorem, the a p p r o x i m a t e d e t e r m i n a t i o n by means of Engel curves was some p r el im i n a r y of presented. utility Using func­ the Phisit results Engel of the curves illustrations indicated utility thirteen and the M.S.U. were that, cross given. under functions price These certain could be sectional studies indices, two on approximated. th e numerical illustrations, circumstances, Setthawong the at least, empiriral ACKNOWLEDGMENTS The author to Dr. Anthony support Y. C. throughout Special wishes Koo who this thanks who approved the Agricultural Economics, this Special study. Stephenson, she id , and made m a n y are Robert valuable for for thi s making to Dr. grant Michigan due appreciation encouragement a nd from is supervisor, to Drs. Gustafson Lester M a n d e r s h e i d State appreciation Jan the D e p a r t m e n t of University, given and her to J u d i t h staff. K m e n t a , Lester who read for Mander­ the e a r l y d r a f t s and comments. The Agricu l t u r a l credit has g i v e n due programming are his d e e p s t u dy . programming Thanks to e x p r e s s Economics the M . S . a . Department deserved Consumer Panel data available study. Thanks patience. are also due to my w i f e , P e n s e e , for her TABLE OF CONTENTS Page ACKNOWLEDGMENTS .............................................. ii LIST O F T A B L E S .................................................. v LIST O F F I G U R E S .................................................. vii LIST O F A P P E N D I C E S ............................................. v i i i INTRODUCTION .................................................. 1 Chapter I. REVIEW OF LITERATURE 1. 2. 3. II. III. E n g e l C u r v e s ....................................... 1.1. H i s t o r i c a l R e v i e w ........................ 1.2. Cross Section ........................... 1 .3. T i m e S e r i e s ............................... 1.4. C o n s u m e r P a n e l ........................... 1.5. C o n c e p t s of V a r i a b l e s .................... P r i c e s and N o n - E c o n o m i c F a c t o r s . . . . 2.1. P r i c e s ....................................... 2.2. N o n - E c o n o m i c F a c t o r s .................... F un ct i o n a l Forms of Engel Curves . . . . REVIEW OF M.S.U. 1. 2. 3. CONSUMERPANEL SURVEY . . . G e n e r a l R e m a r k s .................................. M e t h o d s of S e l e c t i o n ........................... C o l l e c t i n g th e I n f o r m a t i o n ................... CROSS 1. 2. ............................... SECTIONAL S T U D I E S .............................. O b j e c t i v e s a nd S o m e G e n e r a l R e m a r k s . . . Statistical Cross Sectional Models . . . 2.1. Estimation Procedure . . . . . . 2.2. R e s u l t s of C r o s s S e c t i o n a l S t u d i e s . 2.3. Income Elasticity Estim at es . . . . 2.3.1. Dairy Products ................ 2.3.2. F a t s and O i l s .................... 2.3.3. F r u i t s ........................... 2.3.4. V e g e t a b l e s ........................ 2.3.5. M e a t , e t c ......................... 4 4 4 7 11' 12 14 16 16 17 21 28 28 29 29 31 31 32 35 35 42 43 46 49 52 55 Page Chapter 2.4. 2.5. D i s t r i b u t i o n s of I n c o m e E l a s t i c i t i e s ........................... A C o m p a r i s o n o f " G o o d n e s s o f Fi t " . . 2.5.1. D i s t r i b u t i o n s of C o r r e c t C o e f f i c i e n t of D e t e r m i n a ­ t i o n ....................... 63 A p p e n d i x A: A p p e n d i x B: A p p e n d i x C: A p p e n d i x D: A p p e n d i x E: A p p e n d i x F: IV. C O M B I N E D S T U D I E S ....................................... 1. 2. G: Values of q k , p k , m, m / q k , • SOME P R EL IM IN A R Y E V I D E N C E ON A P P R O X I M A T I N G E M P I R I C A L U T I L I T Y F U N C T I O N S ......................... 1. 2. 3. O b j e c t i v e s ................................ 94 Utility Functions and Eng el Curves . . . A r e a s for F u t u r e R e s e a r c h .................109 BIBLIOGRAPHY .................................................... iv 64 65 66 68 70 73 76 Objec t i v e s a n d Some Ge ne ralRemarks . . . 79 S t a t i s t i c a l C o m b i n e d M o d e l s ............ 2.1. E s t i m a t i o n P r o c e d u r e ................... 2.2. R e s u l t s of C o m b i n e d S t u d i e s . . . . 2.2.1. I n c o m e and P r i c e E l a s t i c i t i e s ................... Appendix V. C o m p o s i t i o n of D a i r y P r o d u c t s . . C o m p o s i t i o n of F a t s and O i l s . . C o m p o s i t i o n of F r u i t s ................. C o m p o s i t i o n of V e g e t a b l e s . . . C o m p o s i t i o n of_Me at, ^2.. . . V a l u e s of Y k , M, a n d M / Y k . . . 59 60 76 82 86 89 93 94 94 112 LIST OF TABLES E s t i m a t e s o f R e g r e s s i o n C o e f f i c i e n t s for D a i r y P r o d u c t s Based o n A l t e r n a t i v e F u n c ­ t i o n a l F o r m s .......................................... 37 E s t i m a t e s of R e g r e s s i o n C o e f f i c i e n t s for F a t s and Oils Based on A l t e r n a t i v e Functio nal Forms .................................................. 38 E s t i m a t e s of Fruits Based 39 R e g r e s s i o n C o e f f i c i e n t s for on Alt e r n a t i v e Functional Forms E s t i m a t e s of R e g r e s s i o n C o e f f i c i e n t s for V egetables Based on Alternative Functional Forms .................................................. 40 E s t i m a t e s o f R e g r e s s i o n C o e f f i c i e n t s f or M e a t , etc. B a s e d o n A l t e r n a t i v e F u n c t i o n a l Forms .................................................. 41 I n c o m e E l a s t i c i t y E s t i m a t e s for D a i r y Products Based on A l t e r n a t i v e Functional Forms .................................................. 44 I n c o m e E l a s t i c i t y E s t i m a t e s for F a t s O ils Based on Al ternative Functional 47 and Forms . I n c o m e E l a s t i c i t y E s t i m a t e s for F r u i t s B a s e d o n A l t e r n a t i v e F u n c t i o n a l F o r m s ................... 50 I n c o m e E l a s t i c i t y E s t i m a t e s for V e g e t a b l e s Bas ed on A l t e r n a t i v e Fu nc t i o n a l Forms. 53 I n c o m e E l a s t i c i t y E s t i m a t e s for M e a t , et c. B ase d on A l t e r n a t i v e F u n c t i o n a l Forms. 56 T h e A c t u a l D a y s a n d H o l i d a y s I n c l u d e d in the F o u r W e e k s o f E a c h P e r i o d f o r the Y e a r o f 1 9 5 8 ...................................................... 58 D i s t r i b u t i o n s of I n c o m e E l a s t i c i t y E s t i m a t e s for F o o ds B a se d on A l t e r n a t i v e F u n c t i o n a l Forms .................................................. 59 v Ta ble Page 13. Values 14. D i s t r i b u t i o n s of C o r r e c t e d C o e f f i c i e n t of D e t e r m i n a t i o n Based on Al te rn a t i v e Fu nc ti on al F o r m s .................................................. 63 P r i c e I n d i c e s of F i v e C o m p o s i t e F o o d s B a s e d o n M . S . U . C o n s u m e r P a n e l D a t a o f 195 8 ( 1 9 5 5 - 5 7 = 1 0 0 ) ...................................... 80 E s t i m a t e s of A u t o c o r r e l a t e d C o e f f i c i e n t s for F i v e C o m p o s i t e F o o d s ............................... 87 E s t i m a t e s of R e g r e s s i o n C o e f f i c i e n t s for F i v e C o m p o s i t e F o o d s a f t e r E l i m i n a t i n g the A u t o r e g r e s s i v e E f f e c t s ............................... 88 I n c o m e an d P r i c e E l a s t i c i t y E s t i m a t e s for F i v e C o m p o s i t e F o o d s a f t e r E l i m i n a t i n g the A u t o r e g r e s s i v e E f f e c t s ............................... 90 15. 16. 17. 18. of an d n (Numb e r vi ofOb se rv at i o n s ) . . 61 LIST OF F I G U R E S Figure 1. 2. 3. 4. 5. 6. Page A G r a p h i c P r e s e n t a t i o n of I n c o m e E l a s t i c i t y E s t i m a t e s for D a i r y P r o d u c t s B a s e d on A l t e r n a t i v e F u n c t i o n a l F o r m s ....................... 45 A G r a p h i c P r e s e n t a t i o n of I n c o m e E l a s t i c i t y E s t i m a t e s for F a t s a n d O i l s B a s e d on A l t e r n a ­ t i v e F u n c t i o n a l F o r m s ............................... 48 A G r a p h i c P r e s e n t a t i o n of I n c o m e E l a s t i c i t y E s t i m a t e s for F r u i t s B a s e d o n A l t e r n a t i v e F u n c t i o n a l F o r m s ...................................... 51 A G r a p h i c P r e s e n t a t i o n of I n c o m e E l a s t i c i t y E s t i m a t e s for V e g e t a b l e s B a s e d o n A l t e r n a ­ t i v e F u n c t i o n a l F o r m s ............................... 54 A G r a p h i c P r e s e n t a t i o n of I n c o m e E l a s t i c i t y E s t i m a t e s for M e a t , etc. B a s e d o n A l t e r n a ­ t i v e F u n c t i o n a l F o r m s ............................... 57 A Diagram Showing Wald' s Method, with ThreeD i m e n s i o n a l C o m m o d i t y Space and Two C o n s u m p t i o n E x p a n s i o n P a t h s ....................... 99 LIST OF APPENDICES Page Appendix A. Composition of B. C o m p o s i t i o n of Fats C Composition Fruits D C o m p o s i t i o n of E C o m p o s i t i o n of M e a t , F Values of Y G Values o£ qk of k Dairy Products and Oils. . Vegetables. M, M/Yfc p k , m, etc.. . m/c7k , p k / q k viii 64 65 66 68 70 73 93 INTRODUCTION The functional to e x p e n d i t u r e good the on (or q u a n t i t y is g e n e r a l l y functional from t he budget vided loci of functional is the with fix ed normally circumstances, the Engel between and the Fitting utility Theoretically, curve the is d e r i v a b l e income, But, utility the search curve Engel and variable a direct Engel income a particular indifference is k n o w n . of of) curve. the unknown, relationship inevitable. Engel prices function from disposable purchased ol tangcncies utility function being data termed relationship surfaces the relationship from curve, f u n c t i o n m i g h t be on pro­ the the o b s e r v e d in c e r t a i n approximately determined. Most ically time lar used previous cross to e s t i m a t e functional the M . S . U . E nge l mate sectional Engel the utility on Panel (2) m o d i f y Engel curves of a p a r t i c u l a r income elasticities. selected Engel functions the data for the class­ period of A particu­ functional curves. p re s e n t study, Consumer curves, or form w a s r e l a t i o n s h i p of In the studies the a u t h o r data the of Engel by means 1 of 1958 will make to (1) curves, Engel and use analyze (3) curves. of the approxi­ 2 In a n a l y z i n g the Engel curves, the Engel cu rv es are sectional studies on composite foods . Three the functional way, one based can on relationship investigate three fer en t . of if alternative In a d d i t i o n , functional functional one are fo r In income e l a s t i c i t y forms a better five selected curves. investigate gives cross set o u t Engel functional can form uni fo rmly forms the the thirteen are for this estimates widely dif­ if a p a r t i c u l a r "goodness of fit" to the o b s e r v a t i o n s . In m o d i f y i n g time series dat a ticities for are five Statistically, reliable tha n studies, since tion of limited on is p o s s i b l e lowing is are sectional and p r i c e elas­ estimated. e l a s t i c i t y e s t i m a t e s ar e from individual are used in cross of the more sectional th e e s t i m a ­ the e s t i m a t i o n o f because and price continuous collec­ data. the p r e s e n t sectional on of the utility the o u t l i n e s the o r d e r study studies the e s t i m a t i o n for cross income foods In a d d i t i o n , to a p p r o x i m a t e As Dot h income certain circumstances, used curves, more observations the p a n e l cross pooled. those ob ta in ed Lastly, the Engel composite these tion p r o c ed ur e. elasticities the attempts the Engel income fitted to s h o w curves are elasticities. Engel curves that not In might be functions. of the p r e s e n t of discussion. study, the fol­ 3 In C h a p t e r studies sumer are III, curves set out combined out the Panel Chapter Engel on for Engel Survey some curves is is b r i e f l y survey of s e t out. reviewed sectional based three alternative for on five of composite composite areas f oo d s . utility for future Engel Some functions research, The empirical M.S.U. studies foods . th e m o d i f i e d th e in C h a p t e r cross on a p p r o x i m a t i n g and a general thirteen analyses five I, on by means of given In the In C h a p t e r are preliminary are II. functional curves Con­ forms IV, set findings Engel curves, in C h a p t e r V. CHAPTER REVIEW OF 1. 1.1. Historical household has a lon g and Engel.^ Engel Curves history, relationships study was based which had been and the was The early at l e n g t h in C. C. L i v i n g (New Y or k : dating made data into three public relationships expenditure back by E r n s t Ducpetiax's upon functional first and mo s t classified dependent the household certainly Perhaps on s t u d y of income these families LITERATURE Review The empirical between I as famous Engel for far 153 in as LePlay s t u d y of 1857. Belgian socio-economic assistance; on goods families 2 The families, groups: just s t u d i e s of f a m i l y b u d g e t s a r e c o n s i d e r e d Zimmerman, C o n s u m p t i o n and S t a n d a r d of D. V a n N e s t r a n d , 1 93 6 ) . ^ E r n s t E n g e l ( 1 8 2 1 - 9 6 ) , D i r e c t o r of t h e P r u s s i a n B u r e a u of S t a t i s t i c s , w a s an a d m i n i s t r a t o r w h o p u b l i s h e d many prominent articles. F o r a l i s t o f h is w o r k s , se e J. A. S c h u m p e t e r , H i s t o r y of E c o n o m i c A n a l y s i s (New Y o r k : O x f o r d U n i v e r s i t y P r e s s , 1954 ) , f o o t n o t e 14] p. 961. It is i n t e r e s t i n g to not e t h a t E n g e l ’s w o r k w a s m a i n l y i n f l u e n c e d b y two o f h i s c o n t e m p o r a r i e s . O n e w a s the F r e n c h e n g i n e e r F. L e P l a y , w h o h a d c o l l e c t e d b u d g e t s fro m h o u s e h o l d s a l l o v e r E u r o p e m o s t l y , it s e e m s , f r o m h u m a n i t a r i a n interest. The o ther was the B e l g i a n S t a t i s t i ­ c i a n y u e ' t e l e t , w h o w a s a f i r m p r o p o n e n t of the i d e a t h a t h u m a n c h a r a c t e r i s t i c s , at l e a s t o n th e a v e r a g e , w e r e g o v ­ e r n e d by laws as d e f i n i t e as t h o s e w h i c h g o v e r n p h y s i c a l p h e n o m e n a ; see H. S. H o u t h a k k e r , "An I n t e r n a t i o n a l C o m p a r i ­ son o f E x p e n d i t u r e P a t t e r n , C o m m e m o r a t i n g the C e n t e n a r y o f E n g e l ' s L a w , " E c o n o m e t r i c a (October, 1957), p. 532. 4 5 able to live comfortable Eng el the to a the states to increases. originally in from as himself, of this of in study, a family, expenditure food." 3 living that In o t h e r expenditure though from the viewpoint Eng el's works, by total standard anyone economists. results its nor sional economists of of "The p o o r e r p r o p o r t i o n of the Engel budgets revived consumption: families of words, devoted the h o u s e - 4 family was the and the b a s i s 1857, importance Aside On the p r o v i s i o n that Neither its l a w of fo o d d e c r e a s e s hold assistance; proportion be d e v o t e d la w such circumstances. proposed the g r e a t e r must without did obtained from of A l l e n and to u n d e r s t a n d the 1935 analysis that Bowley.^ the of among law realized theory. analysis attention not until his to h a v e economic the q u a n t i t a t i v e It w a s begun published seemed of not a t t r a c t m u c h the w o r k have else, he 5 of profes­ interest Since significance then, of the b u d g e t data. 3 G. J. S t i g l e r , " T h e H i s t o r y o f E m p i r i c a l S t u d i e s of C o n s u m e r B e h a v i o r , " J o u r n a l of P o l i t i c a l E c o n o m y , V o l . 42 {April, 1954 ), p. 98. E n g e l a l s o a s s e r t e d tha t the w e a l t h i e r a n a t i o n , the s m a l l e r the p r o p o r t i o n of fo o d to t o t a l e x p e n d i t u r e . I b i d ., f o o t n o t e 9. Family ^ S . J. Budgets P r a i s a n d H. (Cambridge: ^Schumpeter, S. H o u t h a k k e r , T h e A n a l y s i s U n i v e r s i t y P r e s s , 1971), p. o p . c i t . , p. 961. ^ T h e s t u d y w a s d o n e by R. G. B o w l e y , F a m i l y E x p e n d i t u r e (London: D. A l l e n an d A. S t a p l e , 1935), L. of 79. 6 As time it is o f t e n on the passed, stated average expenditure rate, i.e., that "percentage on income"; with income, is inelastic demand slightly. expenditure f u n c t i o n of increases food law changed but at with Now food 7 is or: a lesser respect to „8 In the devoted as: a decreasing "food income. Engel's to last 35 y e a r s , the m e a s u r e m e n t Q Engel's by numbers law of The Wharton cated the U. S . , 7 the elasticity income in Schumpeter, op. h as been studies.^ ^ few exam pl es . that, effort has been of fo o d 1 A consumption. confirmed of tremendous school The food and repeatedly following survey, household c i t . , p. tested in 1950, arc a indi­ expenditures to o k 961. 0 North J. S. Holland, Cramer, Empirical 1 9 6 9 ) , p~ 135. Econometrics (Amsterdam: 9 Factors p . 7 0. M. C. B u r k , I n f l u e n c e s of E c o n o m i c a n d S o c i a l o n U.S. Food~Consumption (Minn. : B u r g e s s , F $ 6 1) , K e c c n t s t u d i e s a l s o s h o w i n t e r e s t in o t h e r h o u s e ­ h o l d ite ms , s u c h as h o u s i n g , c l o t h i n g , h o u s e f u r n i s h i n g s , and services. For a p a r t i a l l i s t of s t u d i e s of t h e s e s u b ­ ject s , see R. F e r b e r , " R e s e a r c h o n H o u s e h o l d B e h a v i o r , " in S u r v e y s of E c o n o m i c T h e o r y , Vol . Ill, S u r v e y X I I (New Yo r k : St. M a r t i n 's P r e s s , 196 6 ), f o o t n o t e 3, p. 138. These s t u d i o s y i e l d l o w i n c o m e e l a s t i c i t i e s for h o u s i n g , e l a s t i c i ­ tie s c l o s e to u n i t y for c l o t h i n g , a n d h i g h e r e l a s t i c i t i e s for v a r i o u s t y p e s of r e c r e a t i o n , p e r s o n a l c a r e , h o m e o p e r a ­ tion, a n d o t h e r s e r v i c e s ; se e F e r b e r , I b i d . , p. 139. ^ S i m i l a r l a w s h a v e a l s o b e e n f o r m u l a t e d for o t h e r i t e m s of e x p e n d i t u r e . For e x a m pl e : S c h w a b e ' s law s t a t e s t h a t the p e r c e n t o f i n c o m e s p e n t for h o u s i n g d e c l i n e s as i nc om e rises; see F e r be r, I b i d . ^ F o r a l i s t o f s t u d i e s , s e e the b i b l i o g r a p h y by J. N. M o r g a n , "A R e v i e w o f R e c e n t R e s e a r c h o n C o n s u m e r B e h a v i o r , " in C o n s u m e r B e h a v i o r : Research on Consumer R e a c t i o n s , e d . b y L. H. C l a r k (New Yor k: Harper & Bros., 1 9 5 8 ), pp. 9 3 - 2 1 9 . 7 up a b o u t income was $10,000. about 30% of income $5,000, 12 40 household surveys le s s equal; the h i g h e s t lowest 0.344 for Food ing e s t i m a t e s in v a r i o u s in years 1960; for based on 30 c o u n t r i e s , food in 0.731 report for in 1962, 0.30 0.23 of countries were all but not similar, Poland 17 and the expenditure 1955; 1965; t he Recently, published in in analyses the for e l a s t i c i t y of income was that were 1965 household found ( m id d le c l a s s ) . in B r i t a i n : 0.27 these figure was income household regression They Britain income when when t h a n one . Survey of 21% from a bout elasticities National only Houthakker, significantly 0.25 but disposable 0.28 and the follow­ on fo o d in 1958; 0.23 in 1 9 6 6 . 14 In o r d e r Engel curves, and d at a 1.2. that Cross The sectional it to u n d e r s t a n d is n e c e s s a r y have been widely the empirical to r e v i e w some results of techniques used. Section s t u d y of data Engel obtained curves frequently from a sample of uses cross households for a 12 T h e U.S. B u r e a u of L a b o r S t a t i s t i c s f o r the W h a r t o n S c h o o l of F i n a n c e , U n i v e r s i t y of P e n n s y l v a n i a : S t u d y of C o n s u m e r E x p e n d i t u r e s , I n c o m e s a n d S a v i n g s , Vol. 1-2 (Uni versTi ty of P e n n s y l v a n i a P r e s s , 19 5 67 ■ 13 'H. S. H o u t h a k k e r , "An I n t e r n a t i o n a l C o m p a r i s o n of E x p e n d i t u r e P a t t e r s , C o m m e m o r a t i n g the C e n t e n a r y of E n g e l ' s L a w , " E c o n o m e t r i c a , Vol . 25 (October, 1 9 5 7 ) , pp. 5 3 0 - 5 1 . ^ 4T h e N a t i o n a l F o o d S u r v e y C o m m i t t e e , D o m e s tic F o o d C o n s u m p t i o n a n d E x p e n d i t u r e (London: H.M.S.O., 1965), p. 136. 8 particular w ee k , The period a month, techniques tion, and th i s arc food less $6,000. any other may be convenient single a day, interval. regression system of equ a t i o n s a have 16 equa­ been used is the o l d e s t obtained Lansing $4,000; -0.20 the 0.10 for technique. following area: for 0.26 those households 17 West, income for with elas­ households incomes receiving of more 1R Single technique The period elasticity, in th e than and or 15 elasticities. technique, $4,000-56,000; cross of elasticity for receiving than a ye a r , income Arc ticities time. simultaneous to e s t i m a t e using of regression to i n v e s t i g a t e sectional stu dy , equation is income-food the Engel the most popular relationships. curve is g e n e r a l l y In a stated 15 T h e r e ar e a t l e a s t t h r e e p o s s i b l e m e t h o d s o f c o l ­ l e c t i n g the d a t a : pe rso nal interview, mail, and telephone. F o r a d i s c u s s i o n of r e l a t i v e m e r i t s of t h e s e m e t h o d s , s e e R. F e r b e r a n d P. J. V e r d o o r n , R e s e a r c h M e t h o d s in E c o n o m i c s a n d B u s i n e s s (New York: M a c m i 1 lan , 1962) , p"! 2 0 9 - 1 3. 16 York: . K. A. Fox, I n t e r m e d i a t e E c o n o m i c J o h n W i l e y & Sons , 1 9 6 8 ) , p. 72. Statistics ^ F o r a d i s c u s s i o n of t h i s t e c h n i q u e , s e e W. W a i t e a n d H. C. T r e l o g a n , A g r i c u l t u r a l M a r k e t P r i c e s e d .; N e w York: J o h n W i l e y - & S o n s , 19 51) , p^ 41. (N^w C. (2nd 18 J. G. W es t , " E s t i m a t e s of I n c o m e E l a s t i c i t y of C o n s u m e r P a n e l D a t a " ( u n p u b l i s h e d P h .D . d i s s e r t a t i o n , D e p a r t ­ m e n t of A g r i c u l t u r a l E c o n o m i c s , M i c h i g a n S t a t e U n i v e r s i t y , 1958 ) . In a c r o s s s e c t i o n a l s t u d y , p r i c e s a r e h e l d reasonably constant. E x p e n d i t u r e o n a p a r t i c u l a r g o o d is p r o p o r t i o n a l to th e p h y s i c a l q u a n t i t y . E i t h e r q u a n t i t y or 9 Y Xk = + U ik whore Y., lk j M^ is U . is J- /C s the ihousehold oxDenditure the i^?- h o u s e h o l d income, the stochastic the effects introduced int o the e q u a t i o n in the function the a s s u m p t i o n that except differences the for t he stochastic implies that much the the on same It B's. is estimates of mainly the in obtained good 0.56 it are in household of and Engel curve. the homogeneous and assumption average, B does on the e q u a t i o n homogeneity on explicitly errors the both is a p p r o p r i a t e households The not variable, f o r m of f^, A would, as an d in v a r i a b l e s term. household k— as different error are the d e p e n d e n t functional the k^il g o o d , representing vnriable s that is a s p e c i f i c Regarding term of measurements f^ error on if A ' s spend as income were 20 interesting income elasticity neighborhood for to p o i n t o u t the of United for 0.50. States food that cross in m o s t sectional studies For example: in 1941; Stone, fall Tobin et. a l ., e x p e n d i t u r e m a y bo use d a s the d e p e n d e n t v a r i a b l e . This is the t e c h n i q u e of s c a l i n g of v a r i a b l e s . The r e g r e s s i o n c o e f f i c i e n t s and t h e i r s t a n d a r d e r r o r s a r e d i f f e r e n t by m e r e c h a n g e s of u n i t s . F o r a full d i s c u s s i o n o f t h i s t e c h ­ n i q u e , see A. S. G o 1d b e r g e r , E c o n o m e t r i c T h e o r y (New Y o r k : J o h n W i l e y & Sons, 1964), pp. 1 8 5- 8 6. 20 wood L. Cliffs: R. K l e i n , Prentice I n t r o d u c t i o n to E c o n o m e t r i c s Hal 1, 196 2) , pT 54. (Engle­ 10 estimated Jureen 0.53 obtained estimated 0.58 for average over for 0.40 the ior States at d i f f e r e n t The upon purely exogenous. more tice, thus the the however, far, 21 only and Clark, United States in 1948; Burk cross in 1950; for Snyder fo o d of section 0.54 family 1880-1950 (of e t al . , obtained obtained an calculated budgets from studies individual in cities, 21 structural regression equation If h o u s e h o l d simultaneous been used household income income simultaneous rarely that system to e s t i m a t e the Wold 1933; presupposition appropriate 1938; in during single in Sweden States dates). priate exogenous, the Kingdom for elasticity hundred the U n i t e d United 0.51-0.53 United income three the is not is a p p r o ­ income purely of e q u a t i o n s would elasticities. system of in analysis the is equations of be In p r a c ­ has, Ungel J. T o b i n , "A S t a t i s t i c a l D e m a n d F u n c t i o n for F o o d in t h e U . S . A . , " J o u r n a l of the R o y a 1 S t a t i s t i c a l S o c i e t y , S e r i e s A (1 p . 119; iT! S t o n e , c t at. , T h e M e a s u r e m e n t of C o n s u m e r E x p e n d i t u r e a n d B e h a v i o r in the United Kingdom, 1920-38 ( C a m b r i d g e : U n i v e r s i t y P r e s s , 1954) , p~! 3 27 ; FH W o l d a n d L. J u r e e n , D e m a n d A n a l y s i s (New Y o r k : J o h n W i l e y & S o ns , 1953 ), p^ 30 3 ; F . C l a r k , et al., " F o o d C o n s u m p t i o n o f U r b a n F a m i l i e s in t he U n i t e d S t a t e s , " A g r i c u l t u r a l I n f o r m a t i o n B u l l e t i n No. 132 ( W a s h i n g t o n ^ D . C . : U.S. D e p a r t m e n t of A g r i c u l t u r e , 1 9 54 ) , p. 39; M. C. Burk, " I n c o m e - F o o d R e l a t i o n s h i p s f r o m C r o s s S e c t i o n a n d T i m e S e r i e s S u r v e y s , " P r o c e e d i n g s of the A m e r i c a n S t a t i s t i c a l A s s o c i a t i o n ( B . E . S . S . , 1 9 57 ) , p. 103; a n d LA W. S n y d e r , ''Long-term c h a n g e s a n d F a m i l y E x p e n d i ­ t u r e , " in C o n s u m e r B e h a v i o r : R e sea rc h on C o n s u m e r R e a c t i o n s , e d . by ET FT! C l a r k (New Y o r k : H a r p e r T B r os . , 1958), pp. 3 6 1 - 6 2 . 1] curves mainly because specification 1.3 . Time of data curves. gating of household of of behavior sectional data, also been used in this type are expenditure time. observations vkt complexity structural cross have Da t a periods the estimation equations. and £ Series besides series the of Th e Engel is g e n e r a l l y the the analysis normally and aggregate obtained household c m ve stated of based on time Engel by income ti m e aggre­ over scries as: = £k ' " t > + u k t where is the aggregate expenditure on the k ^ - good at - u the Mt is t— the period of aggregate time, income at the t^- period of t imc , Uj, is the f^ is a specific The that in function different differences the in the stochastic should 22 be error functional f^ periods Strictly ture stochastic term, form. is a p p r o p r i a t e of time explicit error on the homogeneous variables and for assumption except for differences term. speaking, converted are and in a time to q u a n t i t y series since study, price expendi­ varies H. S. H o u t h a k k e r a n d L. D. T a y l o r , C o n s u m e r in th e U n i t e d S t a t e s : A n a l y s e s a n d P r o j e c t i o n s (2nd e d .; Harvard: U n i v e r s i t y P r e s s , 1 9 7 0 ) , p. ?. Deman 12 over periods s u c h as food, deflator. time. the That following price of food is, i n d e x of are d e f l a t e d l ow e r values sectional for for 23 section time the rather series, food of 0.27 of and 0.23 Sweden; period 1.4. than Tobin for 0.28 Burk Consumer panel 23 footnote For 17, food is computed where as a in P y t is relationships, for seem got the the 0.21 the the and cross estimates of using elasticity Jureen, covered) (depending on States. law, cross example: and period vari­ Engel's terms income Wold 0.2 3 United series For of States; on foot! t h a n in data. where substantially to c o n f i r m an e s t i m a t e United give time stated series (depending for values fo r the 24 Panel Recently, consumer index elasticity time for used ( Y ^ ^ / P ^ t ) *100; initially obtained covered) be price movements, for the commodity may Nevertheless, law wa s a composite food. income studies. of index income-food income elasticity although p. k-— series ables case the q u a n t i t y - the the price manner: Time of In a number data. 25 of This an e x p l a n a t i o n studies type of of this have data made use of is o b t a i n e d phenomenon, see from p. 90, Tobin, o p . c i t ., p. 134; W o l d a n d J u r e e n , o p . c i t ., 303 ; Burk, " I n c o m e - F o o d R e l a t i o n s h i p s , " o p . c i t . , p . 10 3. A c o n s u m e r p a n e l is e s s e n t i a l l y a s a m p l e of p e o p l e w h o a r e i n t e r v i e w e d r e p e a t e d l y o v e r a p e r i o d of time. S t r i c t l y s p e a k i n g , a s a m p l e b e c o m e s a p a n e l o p e r a t i o n if its m e m b e r s a r e i n t e r v i e w e d in at l e a s t t w o d i f f e r e n t p o i n t s in t i m e o n the s a m e g e n e r a l s u b j e c t . If o n l y t w o o r t h r e e 13 the same provide group both of households cross Ferber over sectional appraises and periods time the p a n e l of series data by time. The data information. stating that Time series aggre g at e s have serious disadvan t a ge s b e c a u s e of the f r e q u e n t l y u n s t a b l e e s t i m a t e s of i n c o m e e l a s t i c i t i e s . . . . On th e o t h e r h a n d , c r o s s s e c ti o na l d a t a are e s s e n t i a l l y s t a t i c . . . Hence, a c o m b i n a t i o n o f the t w o t y p e s o f d a t a w o u l d s e e m to o f f e r a m u c h m o r e p o w e r f u l t e c h n i q u e for u n d e r s t a n d ­ ing c o n s u m e r b e h a v i o r . By k e e p i n g ture c a n be household's which obtained, not purchasing decisions data Tg parameters.*' notes records, only of behavior, arc made. Marschuk sectional continuous However, but factors a lso of pic­ influencing the m a n n e r a in 27 that increases the a comprehensive the the combining accuracy combined time of series and cross the e s t i m a t e d studies face some " w a v e s " of i n t e r v i e w s a r e i n v o l v e d , t h e r e is a t e n d e n c y to u s e the t e r m " r e i n t e r v i e w s a m p l e " r a t h e r t h a n " p a n e l . " Then a g a i n , if the s a m e p e o p l e a r e i n t e r v i e w e d s e v e r a l t i m e s o n d i f f e r e n t a s p e c t s of the s a m e s u b j e c t , n e i t h e r " p a n e l " nor " r e i n t e r v i e w s a m p l e " m a y be u s e d to d e s c r i b e the o p e r a t i o n . For m o r e d i s c u s s i o n of the c o n s u m e r p a n e l , s e e F e r b e r a n d V e r d o o r n , op. c i t . , pp. 2 6 7 - 7 6 ; G. G. Q u a c k e n b u s h a n d J. D. Shaffer, " C o l l e c t i n g F oo d P u r c h a s e Data by C o n s u m e r Panel, 1951-58," T e c hnical Bulle ti n 2 7 9 , M.S.U. A g r i c u l t u r a l E x p o r i m o n t S ta t"ion ( A u g u s t , 1 9 6 0 ) . *■ F e r b e r , o p . ci t . , p. 2 7 l b i d . , p. 28 141. 145. J. M a r s c h a k , " R e v i e w of S c h u l t z , T h e o r y a n d M e a s u r e m e n t of D e m a n d ," E c o n o m i c J o u r n a l , Voir. 3*9 (19 39) , p . 4 87. 14 difficulty function in f, and k With Consumer interpretation the Data income e l a s t i c i t y Crockett, Research using Concepts regression dependent of usinq of variable, f ou n d panel America for expenditure. independent different variables Some others variable, Nevertheless, Sparks, was about consumer analysis. independent the the food the that of M.S.U. the e s t i m a t e 0.25.^® data for using Similarly, the M a r k e t 1 9 5 1 - 5 3, o b t a i n e d food of of an 0.23.-*^ of V a r i a b l e s ferent c o n ce pts as for 1955-58, of 29 analysis, income elasticity Besides total of Corporation estimated 1.5. disturbance. the c o m b i n e d Panel and s p e c i f i c a t i o n some The use variable several other are techniques also studies used use use of o b s e r v e d 32 of the As income, or has b e e n w i d e l y concepts in data, dif­ single expenditure use q ua ntity. studies and for as the others current the use income accepted. income have been 29 F o r a full d i s c u s s i o n of t h i s p r o b l e m , s e e E. K u h , Capital Stock Growth: A Micro-Econometric Approach ( Am s te r d a m : N o r t h H o l l a n d , 1 9 6 3 ) , p p . 1 1 6 - 4 0 a n d p p . 15 86 3; Also, J. K m e n t a , E l e m e n t s of E c o n o m e t r i c s (New Y o rk : M a c m i l l a n , 1971), p p . 5 0 8 - 1 7 . 30 W. 11. S p a r k s , " E s t i m a t e s of th e D e m a n d f o r F o o d f r o m C o n s u m e r P a n e l D a t a " ( u n p u b l i s h e d Ph.D. d i s s e r t a t i o n , Depart men t of A g r i cu lt u r a l Economics, M i c h i g a n St ate U n i ­ v e r s i t y , 1961). 31 J. C r o c k e t t , "A N e w T y p e of E s t i m a t e of t h e I n c o m e E l a s t i c i t y of the D e m a n d f o r F o o d , " P r o c e e d i n g s o f the A m e r i c a n S t a t i s t i c a l A s s o c a t i o n (B .E. S .S . , 5T9 5 7 ) , p p . 1 1 7 - 2 2 . 32 P . 11. For a discussion of this problem, s ee p. 8 and 15 proposed. relative Among income them, have Briefly, the i— t— period b u t on of the on household of the time ratio the would The variable income use can are be for income income income. of hypothesis on k— the not on income on the not o n equals at its o b s e r v e d and and that the income, the m e a n income income hypothesis, k^- commodity its th e states commodity income permanent and permanent income observed the of known. depend expenditure observed transitory well relative between ii-ii h o u s e h o l d its p e r m a n e n t been concepts expenditure the g r o u p . A s where the the the transitory permanent depends income, income plus 34 tota l expenditure justified unavailable, or on as the g r o u n d s that th e the independent that available the d a t a data on of 33 ' T h e r e l a t i v e i n c o m e h y p o t h e s i s s e e m s to h a v e b e e n f i r s t p r o p o u n d e d by P. B r a d y and R . F r i e d m a n . Much a d d i ­ tional t h e o r e t i c a l a n d e m p i r i c a l s u p p o r t of t h i s h y p o t h e s i s w a s p r o v i d e d b y the w o r k o f M o d i g l i a n i and o f D u e s e n b u r r y . See D, S. B r a d y a n d K. F r i e d m a n , " S a v i n g s a n d the I n c o m e D i s t r i b u t i o n , " N . B . E . R . , S t u d i e s in I n c o m e a n d W e a l t h , Vol. 10 (New York , 1947), pp. 2 4 7 - 6 5 ; F. M o d i g l i a n i , " F l u c ­ t u a t i o n s in th e S a v i n g - I n c o m e R a t i o : A P r o b l e m in E c o n o m i c Forecasting," N . B . E . R . , S t u d i e s in I n c o m e a n d W e a l t h , Vol. 11 (New Y o r k , 1949) , pp. 3 7 1 - 4 4 3 ; a n d J . D u e s e n b u r r y , I n c o m e , S a v i n g a n d the T h e o r y of C o n s u m e r B e h a v i o r ( C a m b r i d g e : H a r v a r d U n i v e r s i t y P r e s s , 1952). a M. F r i e d m a n h a s g r e a t l y e l a b o r a t e d a n d t e s t e d th e pe r m a n e n t income hypothes is . M. D u n s i n g a n d M. G. R e i d , a n d M. N e r l o v e h a v e e x p l o r e d the a p p l i c a t i o n s of t h i s h y p o t h e s i s to f o o d s . See M. F r i e d m a n , A T h e o r y of t h e C o n ­ sumption F u n c t i o n (Princeton: N a t i o n a l B u r e a u of E c o n o m i c R e s e a r c h , 195 7); M. D u n s i n g and M. G. R ei d , " E f f e c t of V a r y ­ ing D e g r e e of T r a n s i t o r y I n c o m e o n I n c o m e E l a s t i c i t y o f E x p e n d i t u r e s , " J o u r n a l of A m e r i c a n S t a t i s t i c A s s o c i a t i o n , Vol. 53 (June, 1958) , p p . 3 5 7-59; m T N e r l o v e , rnfEe I m p l i c a t i o n s o f F r i e d m a n ' s P e r m a n e n t I n c o m e H y p o t h e s i s for D e m a n d A n a l y s i s , " A g r i c u l t u r a l E c o n o m i c R e s e a r c h ( J a n u a r y , 1 9 58 ). 16 income it are total highly unreliable expenditure the e l a s t i c i t y is u s e d refers, elasticity, not income between two is Stone, the et ticities income al., of be slight. For that reduced and influences the by total The total variable, expenditure difference empirical example. expenditure 10?, in o r d e r Prices household income-, and elas­ to a p p r o x i m a t e factors on expenditure household Non-Kconomic other non-economic might factors have such Factors as significant behavior. Prices Prices Enge l the Nevertheless, independent to an 35 e l a s t i c i t i e s .^ Besides 2.1. the course, 2. prices as distorted. elasticity."*6 realized should and curves, variable in vary prices the over tim e . should regression be In a t i m e introduced analysis. series as an In a c r o s s study on explicit sectional 3^ T h e use of i n c o m e o b s e r v e d w i t h e r r o r a s the i n d e p e n d e n t v a r i a b l e w i l l lead to s y s t e m a t i c u n d e r e s t i m a ­ ti o n of i n c o m e c o e f f i c i e n t by l e a s t s q u a r e s e s t i m a t e s . For a full d i s c u s s i o n o f th i s p r o b l e m , see C r a m e r , o p . c i t . , p . 139. 36 T h e use of t o t a l e x p e n d i t u r e as the i n d e p e n d e n t v a r i a b l e m a y l e a d to i n c o n s i s t e n t e s t i m a t e s . F o r a full d i s c u s s i o n of t h i s p r o b l e m , see N. L i v i a t a n , " E r r o r s in V a r i a b l e s an d E n g e l C u r v e A n a l y s i s , " E c o n o m e t r i c a , Vol. 29 (1961), pp. 336- 62 ; C r a m e r , o p . ci t . , p . TTiTJ a n d R. S u m m e r s , "A N o t e o n L e a s t S q u a r e B i a s in H o u s e h o l d E x p e n d i t u r e A n a l y s i s , " E c o n o m e t r i c a , 27 ( J a n u a r y , 1959), p. 121. 37 Stone, et a 1 . , o p . c i t . , p. 312. study, prices households are are reasonably likely to presumed face the to b e same constant since s e t of market: p r i c e s except, o e r h a p s , for r e g i o n a l d i f f e r e n t i a l s o r p r i c e *3Q discrimination. Principally, cross sectional studies concentrate Amonq not the price may first, from and much of the the to q u a l i t y that size composition" household. bers the the m o s t and there analysis apparent is of price price differences. 39 is m e a n t religion the m e m b e r s of t he re a r e m a n y household consumption. obvious age there conditions also prices, household household. occupation may as affect Second, external of inconif? a n d probably reflect ol since elasticities. in a s u r v e y , to p e r m i t attributed .actors is h o u s e h o l d we l l income n --E c o n o m ic F a c t n r s economic the of participating variation be Apart hold estimation particularly variation 2 ..1. the households enouah effects, on influence and va ri o u s of composition. and are and And, cause s e x of regional social third, household the h o u s e h o l d . I3y " h o u s e ­ of factors, w h i c h of the class and expenditure, psychological The variations the m e m b e r s habits social non­ mem­ as characteristics 40 38 L. R. Kle i n, A T e x t b o o k of E c o n o m e t r i c s ( E v a n s t o n : Row, P e t e r s o n L Co., 195 3) , p . 213; S t o n e , e t al . , o p . ci t . , p. 312; P r a i s a n d H o u t h a k k e r , o p . c i t . , p. 110. 39 40 Houthakker and Taylor, o p . c i t . , p. 254 . T h e r e h a v e b e e n n u m b e r s of s t u d i e s o f n o n - e c o n o m i c factors. In o r d e r to l i m i t the s u r v e y , t h i s s t u d y w i l l c o n c e n t r a t e on h ou s e h o l d size and h o u s e h o l d co m p o s i ti on . For 18 Of household all the composition Household usually measured or unit each say, by r e q a r d i n q s ome by where used the consumed by an adult by a c h i l d less and an includes ho u s e h o l d are scales, values, and man some "standard" the scale female as the v a l u e 3.5. is year constructed equivalent In fac t, labelled than one sectional size composition 41 a p r o p o r t i o n of who adult male intensively. expendi­ male.^ as and food adult Engel size the T h u s, an detined In a c r o s s stated as household most scale expresses que t was 3.1 q u e t s , studied household male. Ernst factors, equivalent ty p e a child or t r a c t i o n of already This adult been and adult aqe-sex the have size consumers. ture of type, non-economic this scale was the u n i t of food ol d , to a " q u e t" ; that was an a d u l t female 43 stu d y, the household Engel curve that compos!tion may be as: more1 s u r v e y s a n d d i s c u s s i o n s of o t h e r n o n - e c o n o m i c f a c t o r s , see R. O. H e r m a n n , " H o u s e h o l d S o c i o - E c o n o m i c a n d D e m o g r a p h i c C h a r a c t e r i s t i c s as D e t e r m i n a n t s of F o o d E x p e n d i t u r e B e h a v i o r " ( u n p u b l i s h e d Ph.D. d i s s e r t a t i o n , D e p a r t m e n t of A g r i c u l t u r a l E c o n o m i c s , M i c h i g a n S t a t e U n i v e r s i t y , 1 9 6 4 ); Burk, U.S. F o o d C o n s u m p t i o n , o p . ci t . , pp. 5 3-64 ; a n d F e r b e r , o p . c i t . , pp. 1 2 6 - 3 4 . ^ I t s h o u l d be p o i n t e d ou t t h a t h o u s e h o l d s i z e and c o m p o s i t i o n v a r y f r o m h o u s e h o l d to h o u s e h o l d , y e t t h e y v a r y v e r y l i t t l e f r o m y e a r to yea r. Thus, t h es e f a c to rs m i g h t be o m i t t e d in a ti me s e r i e s s t u d y . See H o u t h a k k e r a n d T a y l o r , o p . ci t . , p. 2 7 5 . 42 43 Economy Prais and Houthakker, op. c i t . , p. 126. C . S . B e 1 1 , Consumer Choice m the A m e r i c a n (New Y o r k : R a n d o m H o u s e , 1 9 6 7 ) , p~! 1 0 4 . 19 Y,, = ] 1, f. v (M. , lc N. .) + U iv i , ik : n 1K where N. . is 11 the number in the i— c.-j, is is persons of the of the j— age-sex type household , the e x p e n d i t u r e type Y. of person scale for summation of the th j— age-sex t hi k— good , and the over value -j . J J n t his lent adult scale lor seale . is d i s t i n g u i s h e d of a Ji i.f.oror.i for each th tlic k~ c e m m o d i ty may be scale of commodity, and th k— t c-rim:-i the equiva­ the specific 44 The (the formuiatlon, scale varying s e t of that aye values is b a s e d and sex), may be the nutritional on the nutritional or the actual scale requirements expenditure scale A [* that is c o n s t r u c t e d practice, person and a s e t of for each from the actual nutritional commodity observed scales is for data. each type In of chosen. 44 S o m e r e s e a r c h e r s e x p e c t tha t t h e s c a l e s o f e q u i v a l e n t a d u l t s w i l l be s i m i l a r for all c o m m o d i t i e s , so t h a t it w i l l n o t be n e c e s s a r y in p r a c t i c e to d i s t i n g u i s h a s c a l e for e a c h c o m m o d i t y . 45 F o r a full d i s c u s s i o n o f c o m p u t a t i o n a n d a p p l i c a ­ t i o n of a g e - s e x e q u i v a l e n t s c a l e s , see D. W. P r i c e , " A g e - S e x E q u i v a l e n t S c a l e s tor U n i t e d S t a t e s F o o d E x p e n d i t u r e s — Their C o m p u t a t i o n and Application" (unpublished Ph.D. d i s s e r t a t i o n , D e p a r t m e n t o f A g r i c u l t u r a l E c o n o m i c s , M i c h i g a n S t a t e U n i v e r s i t y , 1965). 20 Traditionally, i, k . *1 income In m o s t are high l y hypothesis household depends Eng el survey only on curve may is to the be for studies data, positive allowing size most effects suppose stated household correlated. the level assume of The per and fo r al l household simplest variations that consumption income = 1 ik siz e 47 of c in per p e r s o n person. The as: 46 T h u a s s u m p t i o n i m p l i e s th a t t h e r e is no d i f f e r ­ e n c e in t h e a m o u n t s p e n t for a n y c o m m o d i t i e s c o n s u m e d by p e r s o n s o f d i f f e r i n g a g e a n d sex. In g e n e r a l , m a n y d i f f e r e n c e s e x i s t in the a m o u n t s p e n t for c o m m o d i t i e s consuiru J by i n d i v i d u a l s of d i l t e r e n t a g e - s e x c o m p o s i t i o n . H o w e v e r , t .is a s s u m p t i o n is a c c e p t a b l e w h e n i n f o r m a t i o n r e g a r d i n g a g o - s o x c o m p o s i ti tin of i n d i v i d u a l h o u s e h o l d s is u i u v d i lab l o . 47 It s h o u l d be n o t e d t h a t the p o s i t i v e c o r r e l a t i o n is not d u e to a d i r e c t c a u s a l lin k b e t w e e n the two v a r i ­ a b l e s b u t to f o r t u i t o u s c h a r a c t e r i s t i c s of the e x i s t i n g s o c i a l s t r u c t u r e , as m a y be i l l u s t r a t e d by the two e x t r e m e i n s t a n c e s w h i c h l a r g e l y d e t e r m i n e the o b s e r v e d c o r r e l a ­ tion. A t o n e e n d of the s c a l e we h a v e h o u s e h o l d s of one or t w o p e r s o n s , w h i c h u s u a l l y r e p r e s e n t the v e r y y o u n g - - b a c h e l o r s a n d y o u n g c o u p l e s - - o r the old; b o t h c a t e g o r i e s t e n d to h a v e s u b s t a n t i a l l y l o w e r i n c o m e s t h a n the a c t i v e a d u l t p o p u l a t i o n . A t the o t h e r e n d of the scale, v e r y l a r g e f a m i l i e s of e i g h t o r m o r e p e r s o n s often include m o r e than on e wag e earner, either b e c a u s e the y a re in f a c t c o m p o s i t e h o u s e h o l d s , or b e c a u s e o f the n a t u r a l a g e s t r u c t u r e of f a m i l i e s w i t h six o r m o r e children. S e e C r a m e r , o p . c i t . , p. 162. 2] This t ion hypothesis of c o n s t a n t returns obviously to scale corresponds often made to in the a s s u m p ­ the theory of p r o d u c t i o n . ^ r u n ci;iona I F o r m s Perhaps ii’.u'i the most of difficult '-nr f>s ■;r. to (-■'[ cess the En gc i C u r v e s part function of the analysis in an of appropriate 48 , . ilio a s s u m p t i o n <«! cni.stunt r e t u r n s to s c a l e is l i k e l y i m p r o p e r s i n c e a l a r g e h o u s e h o l d m a y be a b l e to a t t a i n a h i g h e r l e v e l of p e r c a p i t a c o n s u m p t i o n t h a n a smaller household. P a r t i c u l a r l y w i t h fo o d , e c o n o m i e s m a y ii i.u ■ in p u r c h a s i n g , s t o r a g e , a n t i p r e p a r a t i o n of food. S e v e r a l e m p i r i c a l s t u d i o s h a v e a t t e m p t e d to i n v e s t i g a t e the d e g r e e of e c o n o m i c s ot sca le . For a c l a s s i c e x a m p l e , P r u i s set up the f o l l o w i n g m o d e l : where f^ and g^ are undefined functional forms. In P r u i s ' s m o d e l , if the r e w e r e n o e c o n o m i e s of scale, g^ is zero. N e v e r t h e l e s s , the m o d e l f a c e s t wo d i f ­ ficulties. T h e y are : if f^ is n o t s p e c i f i e d c o r r e c t l y , then p a r t of the v a r i a n c e p r o p e r l y a s c r i b a b l e to M y / N y is i sc r i b e d to 1^ , a n d v a l u e s of My a n d Ny t e n d to b e c o r r e l a t e d so t h a t the c o e f f i c i e n t s of th e r e g r e s s i o n are i m p r e c i s e b e c a u s e the s t a n d a r d e r r o r s of the r e g r e s s i o n c o e f f i c i e n t s b e c o m e large. P r a i s u s e d t h e s e m i - l o g form; w i t h the B r i t i s h d a t a of 19 38, he f o u n d t h a t the e c o n o m i e s of s c a l e a p p e a r e d , b u t w e r e v e r y s m a l l . With a belief that the d i s a d v a n t a g e s of s m a l l h o u s e h o l d s m a y t o d a y bo not so g r e a t , the a s s u m p t i o n of c o n s t a n t r e t u r n s to s c a l e may b e t a k e n as s u b s t a n t i a l l y c o r r e c t in the f o r m u l a t i o n of E n g e l c u r v e s . F o r a f u l l e r d i s c u s s i o n of t h i s p r o b l e m , see S. J. P r a i s , " W o n - L i n e a r E s t i m a t e s of the E n g e l C u r v e , " R e v i e w of E c o n o m i c S t u d i e s , Vol. 20 ( 1 9 5 2 - 5 3 ) . 22 algebraic functional households all were households tion a n d were to d e r i v e regarded a9 as Theoretically the approximately faced by functional particular form. f o r m of the forms the fundamental had the speaking, consumer same p r e f e r e n c e same p ric es , it w o u l d of curves all preference Engel function were be if units, func­ possible provided given. a 50 4n '1ho !>i>.blem of 1 : n 1 inu t h e m o s t ■:o p ropr i a te fo rm of E ng e l c u r v e s is an o l d o n e in e c o n o m e t r i c s . As yet, n o s o l u t i o n appeal s to h-ive f o u n d g e n e r a l a c c e p t a n c e . Gener­ al ly s p e a k i n g , it is p r o b a b l y true t h a t the i n v e s t i g a t i o n of the f o r m of E n g e l c u r v e s has a t t r a c t e d l e s s a t t e n t i o n tha n h a v e m e t h o d s of e s t i m a t i n g p a r a m e t e r s f o r s p e c i f i e d cqii'il ion.cj. Sec C. E. V, L o n e r , " f o r m s of E n g e l F u n c t i o n s , " E c o n o m e t r i c a , 11 ( October, 1963 ) , p. 694. 50 1 u D e n o t e q , ..., q* be a s e t of n g o o d s p u r c h a s e d by the r o p r c s c n t « t i v e consuim i d a p e r i o d o f time; p , p n be the c o r r e s p o n d i n g s e t of p r i c e s ; m is t h e d i s p o s a b l e income; u ( q , ..., q n ) the u t i l i t y i n d i c a t o r . G i v e n p's and m at a p e r i o d of time, t h e fir s t c o n d i t i o n for m a x i m i z ­ ing the u t i l i t y s u b j e c t e d to the b u d g e t c o n s t r a i n t is f u l f i l l e d if the c o n s u m e r p u r c h a s e d the q u a n t i t i e s s u c h as rtU iiq , l T p = n y. p k q k k=l jU , 2 ... rd1, n " .................. ' aq aq - m. S o l v i n g the a b o v e e q u a t i o n s , o n e g e t s th e q u a n t i ­ ties p u r c h a s e d a s f u n c t i o n s of p r i c e s a n d i n c o m e s . In a cross s e c t i o n w i t h c o n s t a n t prices, q u a n t i t i e s p u r c h a s e d w i l l d e p e n d o n l y o n the i n c o m e ; th a t is, q 1 - f 1 (m) , or qk - . fk (m) for These Engel yk By curves - fk (m) , q n = fn (m) , k = 1, are, the can in 2, ..., fact , n. the E n g e l technique of scaling b e r e w r i t t e n as: of curves. variables, th e 23 Unfortunately, function ence ilonc could m a t i ca l is not lation. As and Enqnl Needless curves. functional among Some say, Both economic "The the theory, prefer­ economic of and of theory the m a t h e ­ statistical alqebraic choice in p r a c t i c e , . . . economic the knowledge t h e c h o i c e of form, f o r m of to appropriate influence s i m p l i c i t y ." element functional Goldberqor mentions, appropriate comoromiso unknown. provide f o r m of considerations the formu­ an involves goodness a of fits, b1 researchers from e c o n o m i c believe theory that that can there be is taken at least one over for c2 lovmulating where the yk = pk * alnebraie for k = functional 1, 2, ..., f o r m of Engel curves. n. F o r a lul l diGcustiinn of thi s p r o b l e m , s e e A. W a l d , "The A p p r o x im.it e D e t e r m i n a t i o n o f I n d i f f e r e n c e S u r f a c e s b y M e a n s of E n g e l C u r v e s , " K c o n o m o t r i c a , Vol. 8 (1940), p p . 14 4-46. It is i n t e r e s t i n g to p o i n t o u t that, k n o w i n g th e s h a p e s of E n g e l c u r v e s , the f u n c t i o n a l form o f i n d i f f e r e n c e s u r f a c e s m i g h t be a p p r o x i m.j te J y d e t e r m i n e d . See W ol d and J u r e e n , o p . ci t . , pp. 1 3 0 - 3 1 ; W a l d , o p . c i t . , pp. 14 4-7 5 ; and M. T. D a v i s , T h e T h e o r y of E c o n o m e t r i c s ( B l o o m i n g t o n , Ind.: P r i n c i p i a P r e s s T 1941), p p ” 5 -68™. 51 52 Goldberger, o p . c l t . , p. 217. Tf p o s s i b l e , t h e r e is a n o t h e r e l e m e n t : the s a t u r a t i o n p o i n t o r the p o i n t of z e r o m a r g i n a l u t i l i t y . T h e o r e t i c a l l y , th e s a t u r a t i o n p o i n t is v e r y u n l i k e l y to b e reached. In p r a c t i c e , h o w e v e r , m o s t r e s e a r c h e r s b e l i e v e that if a c o m m o d i t y is a s p e c i f i c item, for an i n d i v i d u a l h o u s e h o l d , the s a t u r a t i o n p o i n t is l i k e l y to o c c u r at a h i g h l e v e l of i n c o m e . O n t h e o t h e r h a n d , if a n u m b e r of c o m m o d i t i e s are a g g r e g a t e d as a c o m p o s i t e c o m m o d i t y , o r if a g r o u p of h o u s e h o l d s r a t h e r t h a n an i n d i v i d u a l h o u s e ­ h o l d is i n v e s t i g a t e d , the .satiety lev el is n o t l i k e l y to be r e a d i e d . See P r a i s .and H o u t h a k k e r , op, cit. , pp. 1 6 - 1 7 ; and C r a m e r , o p . c i t . , p. 149. 24 Assuminq or no saving, t he . o . i i i i j f't .1 that ti.q i ■: element is . Y, > , ’ *■ the budget whi ch restriction a Y ik implies /. whoro IK .jvcrayt' 4. i( n i /r»M -j^ ttin 1 the t fa k— commodity. 11 1 he number of restricted to to is b o u g h t , tha t cumiiioui ty additional the diminish the the steep as slope fit and for to m a k e Engel income As unity. commodities coirunod 1 1 l e s that is for tiro room, are the If are is very slope income bought, mrur* the of As as for increases. statistical some on the l u d g e f rcaf.ri.c- it w e r e , income with the low, only the Engel rises, then, rises, moste l e ­ one curve it is apparent gradually for n e w e n t r a n t s . r -j J it is all c o m m o d i t i e s for successively first commodity will substitutes, curves simplicity), starting income then 1 ; incur, e cc n sutipfiun is commodities. Thu s , situation when commodity that number enter. Fneel c inim- 1i L j e s in vdi y , at. low small new c o m m o d i t i e s mentary <^f the for -if l o w e d ■- = k dMi k ±k valid to become If suppose less 54 considerations researchers (goodness believe that of the 53 B u t t h e r e is no n e c e s s a r y r e a s o n f o r all c o m m o d i ­ t i e s to be s u b s ti L u t e s . Tire i n t r o d u c t i o n of a n e w c o m m o d i t y i n t o t h e b u d g e t r e s t r i c t i o n m i g h t c a u s e the s l o p e s of its c o m p l e m e n t s to ris e. If s e v e r e , t h e s u c c e s ­ s i v e n e w e n t r a n t s m i g h t r e p l a c e the a l r e a d y p r e s e n t c o m m o d i t i e s e n t i r e l y , so t h a t t h e s h a p e s of E n g e l c u r v e s m i g h t be k i n k e d o r d i s c o n t i n u o u s o v e r c e r t a i n r a n g e s of income. 54 Cramer, P r a i s a n d H o u t h a k k e r , o p . c i t . , pp. o p . c i t . , pp. 1 4 7 - 4 9 . 15-17; 25 functional data may and f o r m of reproduce possess. The transformation be applied tions. th at are of F.nqol curves any marked form can should curvature be m a d e the d a t a , broadly so linear that to the correspondingly There are dozens the the observations by linear fi t a simple regression transformed can obscrva- i>5 have some been proposed mathematical empirical studios semi-log, doublc-loq, The of o. lor forms this and iustificaticn a first order fined. Tho 35 J Cramer, of Engel that lunotional cuives. have suhicet. 5 r, been They forms The used ar c : lollowing in m o s t linear, log-normal. of approximation linearity algebraic the linearity to a n y Engel o p . c i t . , p. function curves 147; is tha t which it is u n d e ­ is a c c e p t a b l e Loser, is o p . c i t ., when p. 694 . Jblt m i g h t be t h o u g h t that the p r o b l e m of s e a r c h i n g for the a p p r o p r i a t e for m of E n g e l c u r v e s is t r i v i a l , s i n c e a p o l y n o m i a l o f s u f f i c i e n t l y h i g h d e g r e e c a n a s s u m e any required shape. H o w e v e r , the f l e x i b i l i t y of a p o l y n o m i a l is o n l y a n a d v a n t a g e if the d e g r e e of s c a t t e r of t he o b s e r v a t i o n s is s m a l l e n o u g h to a l l o w a p r e c i s e d e t e r m i n a ­ t i o n of the p a r a m e t e r s o f t h e p o l y n o m i a l . The data p r o v i d e d b y f a m i l y b u d g e t s do n o t .seem to h a v e s u f f i c i e n t r e g u l a r i t y to m a k e t n i s a d v a n t a g e p o s s i b l e . It is t h e r e ­ fore n e c e s s a r y to c h o o s e a f o r m w h i c h s u b s t a n t i a 1 ly r e p r e s e n t s the r e q u i r e d form. See P r a i s a n d H o u t h a k k e r , o p . c i t . , p . 86. F o r s o m e r e s e a r c h e r s , the c h o i c e of th e a p p r o ­ p r i a t e f o r m is i g n o r e d . G e n e r a l ly, t h e y b e l i e v e tha t it will be m o r e i m p o r t a n t to h a v e r e l a t i o n s h i p s w h i c h are c o n v e n i e n t for o n e o r the o t h e r p u r p o s e . S e e C. E . V. L o s e r , " F a m i l y B u d g e t d a t a a n d P r i c e E l a s t i c i t i e s of D e m a n d , " R e v i e w o f E c o n o m i c S t u d i e s , Vo l . 9 (1941), p. 47. 26 the o b s e r v a t i o n s narrow interval The of income where confined curvature curvature .since s u r v e y d a t a are of Engel generally to a r e l a t i v e l y matters curves cover little cannot or be not at neglected a considerable income I'Q ranqe. the Amonq British semi-loq fit" data, forms.^ form of to h i s used 57 found in m o s t Cramer, forms, out was Prais that curves household that in the studies o p . c i t ., and the prelorable Similarly, Engel Israeli Ferber curves found relationship functional semi-log several case of to o t h e r Liviatan gave Houthakker, the foods a alternative found best using that the "goodness of budgets. functional was pp. form of essentially 146-47; the Allen Engel same and as Bowley, o p . cit. S t u v o l and d a m e s , in t h e i r s t u d y of h o u s e h o l d e x p e n d i t u r e o n food in H o l l a n d , s h o w e d tha t n e i t h e r the lino ir n o r the e x p o n e n t i a l f o r m s g e n e r a l l y u s e d in e s t i m a ­ ting i n c o m e e l a s t i c i t i e s w e r e a p p r o p r i a t e f o r the w h o l e r a n g e of b u d g e t s in t h a t c o l l e c t i o n . See G. S t u v e l a n d S, F. J a m e s , " H o u s e h o l d E x p e n d i t u r e on F o o d in H o l l a n d , " J j—o u r n a l of R o y a l S t a t i s t i c S o c i e t y , S e r i e s A, 113 (1950), 69 Prais and Houthakker, o p . c i t . , p. 166. L i v i a t a n , C o n s u m p t i o n P a t t e r n s in I s r a e l (Jerusalem: F a l k , 1964) , p p . 29- 3 0. B e s i d e s its s i m p l i c i t y , the s e m i - l o g f u n c t i o n h a s the f o l l o w i n g p r o p e r t i e s : t h e s l o p e of the c u r v e a n d t h e i n c o m e e l a s t i c i t y d e c l i n e w i t h the r i s e of t h e i n c o m e l e v e l ; the c u r v e h a s no s a t i e t y l e v e l ; the c u r v e d o e s n o t p a s s t h r o u g h its o r i g i n b u t i n t e r c e p t s a p o s i t i v e l e v e l of income. Se e J. J o h n s t o n , E c o n o m e t r i c M e t h o d s (New Y o r k : M c G r a w - H i l l , 1 9 6 3) , p. 47; G o l d b e r g e r , o p . c i t . , p. 214. 27 used by Ernst main reason explained E n q e l , namely, tor by the d o u b l e - l o g t h e p o p u l a r i t y of Ezekiel and Fo x, is form.6 ^ the d o u b l e - l o g The form, as that T h o u g h the i n c o m e e l a s t i c i t y f o r a c o m m o d i t y m a y c h a n q o f r o m o n e i n c o m e level to a n o t h e r , it is o f t e n m o r e d e s i r a b l e to o b t a i n an a v e r a g e e l a s t i c i t y o v e r some s p eci fi ed range of incomes. In fact, t h i s is e q u i v a l e n t to a s s u m e t h a t the i n c o m e e l a s t i c i t y is m n s t i n t ov e r the r a n o o in q u e s t i o n . Another fhe i nt e g r a l proposed by asymptote log-normal Aitchison and Nevertheless, requires ently Danish classic at the this iterative possible, functional f o r m of Engel curve sigmoid response and same curve nr a Bro wn . time is methods, as J o r g e n s e n C3 This passes not e a s y and curve through to fit, in h i s has is curve an upper the o r i g i n . in nonconvergence found curves that it is a p p a r ­ analysis of budgets.^ F e r b e r , o p . c i t . , p. 138. The d o u b l e - l o g form p r o v i d e s for a c o n s t a n t income elasticity. It p a s s e s t h r o u g h the o r i g i n , a n d it h a s an u p w a r d r a t h e r t h a n a downward curvature when the e l a s t i c i t y is g r e a t e r t h a n one. See J o h n s t o n , op. c i t . , p. 48; G o l d b e r g e r , o p . c i t . , p. 215. rn M. E z e k i e l and K. A. Fox, M e t h o d s o f C o r r e l a t i o n and R e g r e s s i o n A n a l y s i s {3rd e d .; N e w Y o r k : J o h n W i l e y & Sons, 1 9 5 9) , p. 110. t ■> F o r a full d i s c u s s i o n of thi s c u r v e , see J. A i t c h i s o n a n d J. A. C. B r o w n , T h e L o g - N o r m a l D i s t r i b u t i o n (Cambridge: U n i v e r s i t y P r e s s , 1957) . 64 of Danish 1 9 6 5 ), p. E. J o r g e n s e n , I n c o m e - E x p e n d i t u r e R e l a t i o n s h i p s Wage and Salary Earner (Copenhagen: Kobenhaven, 55'. CHAPTER REVIEW OF M . S . U . 1_. Since Consumer bri ef data r ev ie w of this The p a n e l holds selected households The p a n e l through household in t h e for home expenditure or the 14 composite fourteen fru it s ; etc.; sugar, operation panel sweets, of ending in weekly item. There were and rep o rt . dairy food; bakery and nuts of 28 February, o n all a 300 house­ to 30,000 100,000 The food 50 0 fa t s and Each pur­ and food following items were a n d o i ls : and e g g s ; cereal and n u t 1951, 1958. price, about fish, and cooking ^For m o r e d i s c u s s i o n Shaffer, o p . cit about products,- poultry, and m i n e r a l s ; of quantity, meat; cand y ; 25,000 in D e c e m b e r , each baby curves, excluded. reported g r o up s : the M . S . U . be g i v e n . ^ a city started in e a c h Engel about th e foods use o f of a p p r o x i m a t e l y giving food prepared first use, vegetables; vitamins and for will was a period make in a n a l y z i n g Michigan, Lansing SURVEY Re m a r k s representative East continued 1958 was c o m p o s e d as PANEL s t u d y wi l l survey in L a n s i n g , inhabitants. chased of CONSUMER Ge n o r a j t.hc p r e s e n t Pane l ]I jam, products; products; beverages; aids. this survey, see Quackenbush 29 In a d d i t i o n , after federal income number of meals away home from censuses don e of m sample on street and was sample census. Size homemaker, car d sorting was d r a w n the the to selected those from refusing The the were 1,885 needed fo r families panel family dropping and survey to the p a n e l asked was the panel panel in were use of then each oriqinal panel sam­ the 1950 educa­ used by as punch N— family member. an d refusals characteristics similar out. Collecting questionnaires were the the Directory. homemaker, replacements with 3. The of households, in M.S.U. households age an City house­ Each of address serialized as were sampled sample original of of Lansing controls, listing or the income four Substitutes were of sample respectively. a random family, families on from of for m e a l s censuses number residential from an d periodic Sample 2,103, excluded. drawn composition, Selection The of section 323 w a s All and every p l e of income expenditure involved L956. composed using and Lansing. 1,775, address controls. of of and its basis. Methods 1954, reported in h o u s e h o l d quests, a weekly City East L a n s i n g w as tion o f to the 1,885, by change procedure census obtained tax, samplina 1950, holds wa s household served 2. The each carried out households. to r e p o r t each week the Information through All mailing households by m a i l i n g in in 30 a purchased food previous wouldn't a diary. panel and was for g et , no neqlect, An e v e n g r e a t e r households weekly visits were indicated in c o m e . had assurance current dispos abl e check These which been mailed to them the week. Ther e weekly diary were or the income high the data. annually aqainst well panel to e n t e r p r o b l e m was generally a reasonably refuse visited reports that annual m some items collection About half in o r d e r reports received. accuracy members the of in the the to v e r i f y of income. This rapport data on observed CHAPTER CROSS SECTIONAL 1. Most sectional Enqel or Enqel previous data of studies on a particular for the true and Enqel period e l a s t i c i t i e s .^ selected Snme G e n e r a 1 Remarks curves of used time A particular functional cross to e s t i m a t e functional f o r m of the curves. In tional STUDIES O b j e c t ivos income for m w a s III this studies composite selected chapter, on foods. the Engel Three for the true In t h i s w a y , the income composite f oo d s , forms, ar e income elasticity functional based obtained. forms thirteen successive curves are alternative functional on three Thus, estimates are w i d e l y one set o ut functional f o r m of elasticity the estimates alternative can based cross on different. five forms Engel for are curves. the five functional investigate three for sec­ if th e alternative In a d d i t i o n , one F o r p u r e e c o n o m i c t h e o r y , an i n c o m e e l a s t i c i t y h a s l ong b e e n u s e d to i n d i c a t e if a c e r t a i n c o m m o d i t y is a luxury, a n e c e s s i t y , or an i n f e r i o r g o o d . For business firms, an i n c o m e e l a s t i c i t y for a p a r t i c u l a r g o o d m a y be used as an i n d e x o f d e m a n d , or m a r k e t p o t e n t i a l sa l e . For e c o n o m i c p o l i c y , i n c o m e e l a s t i c i t i e s m i g h t b e u s e d for adopting various possible policies. See J. M. S l a t e r , "Regional Cons u m e r Exp e n d i t u r e Studies Using Nat io na l Food S u r v e y D a t a , " J o u r n a l of A g r i c u l t u r a l E c o n o m i c s (May, 1 9 6 9 ) , p. 197; G. T i n t n e r , E c o n o m e t r i c s fNew Y o rk : John Wiley & Sons, 1952 ), pp. 5 7 - 6 2. 31 32 can investigate gives a better if a p a r t i c u l a r "goodness 2. The P ane l d a t a data of tnirteen periods fats and and the of as to oils; taken the weekly in 1 9 5 8 , curves These fruits; are the Consumer grouped Since there thirteen cross sectional to be foods vegetables; are Models t i me . able composite Sectional M.S.U. reports of form uniformly given o b s e r v a t i o n s . Cross from a period time Engel f o o d s. are Four treated set o u t are: and meat, were for dairy five products; poultry, fi s h , e g g s .^ In e a c h ticular period assumed per used 1958. and composite fit " S t a t i s t ical together studies on of functional to be capita cross of sectional time, all homogeneous disposable study households except income, and belonging in for p e r to each the p a n e l capita par­ are expenditure, stochastic error.^ 2 T h e o r e t i c a l l y , d i f f e r e n t v a r i e t i e s of g o o d s c a n be g r o u p e d as a s i n g l e c o m p o s i t e g o o d if t h e r e l a t i v e p r i c e s r e m a i n fixed, or t h e y a r c c o n s u m e d in f i x e d p r o p o r t i o n s . For a full d i s c u s s i o n of t h i s p r o b l e m , s e e D. P a t i n k i n , M o n e y , I n t e r e s t , a n d P r i c e s (2nd e d .; N e w York: Harper & iiow, 1965) , p p . 4 1 1 - 1 6 . T h e e x a c t c o m p o s i t i o n of t h e s e g r o u p e d g o o d s is g i v e n in A p p e n d i c e s A, D, C, D, a n d E. 3 In a c r o s s s e c t i o n a l s t u d y , p r i c e s ar e h e l d c o n ­ stant. Th e y are o m i t t e d f r o m the f o r m u l a t i o n of E ng el curves. T h e p e r c a p i t a h y p o t h e s i s is a d o p t e d to c o p e w i t h the i n f l u e n c e of h o u s e h o l d s i z e o n h o u s e h o l d e x p e n d i t u r e behavior. T h e o m i s s i o n of h o u s e h o l d s i z e in t h e f o r m u l a t i o n of E n g e l c u r v e s w i l l r e s u l t in b i a s e d a n d i n c o n s i s t e n t estimates of income e l a s t i c i t y since hou s e h o l d incom e and h o u s e h o l d s i z e , in m o s t s u r v e y d a t a , a r e h i g h l y p o s i t i v e correlated. T h e p e r c a p i t a h y p o t h e s i s m a y be t a k e n as s u b ­ s t a n t i a l l y c o r r e c t in t h e f o r m u l a t i o n of E n g e l c u r v e s . See pp. 1 7 - 2 1 a n d f o o t n o t e 48, C h a p t e r I. 33 In o t h e r w o r d s , posite food, yi k /Ni ■ V where Y-, 1K in e a c h ' is Mj cross curve sectional for th e com­ s t u d y , c a n be s t a t e d as th i— household aggregate expenditure on the food , is th i— h o u s o h o ] d uyyi e y a te the federal lb Enqel * u ik W the k— the is the income taxes, average number of income persons in after the i^il household, lhk is the the stochastic effects besides is In the of c i t h e r household urement of f, k error the representing non-economic size, and reyressand, undefined this chapter, term functional the both factors e r r o r of m e a s ­ and form, the functional forms selected an d double-log f o tm s . for 4 f arc Engel linear, curve for semi-log, the th k— foo d is e x p r e s s e d ^ Linear: Semi-log: Double-log: Y i k / N i = a k2 log = a k 3 as Th u s , the follows: 4 Pk 2 (Mi/ N i ) + U ik + 3 k2 + ^ 3 lo9 + U ik lo9 (M ^ / N ^ ) + U ik 4 in T h e s e t h r e e f u n c t i o n a l for ms h a v e b e e n w i d e l y u s e d t h e a n a l y s i s of E n g e l c u r v e s ; see pp. 26-27 , C h a p t e r I. 34 where ot^ 1 s an d terms, and 6 ^ ' s ar e the income on a l t e r n a t i v e the coefficients functional Regarding t he and the assumptions (i) Normality: (ii) Zero mean: (iii) the v a l u e s is ^^ik^ Homoskedasticity: (iv) No (v) exogenous of are the the constant k-^- food, based distribution of the e x p l a n a t o r y the d i s ­ variable, assumed: normally distributed; “ 2 2 E(U.. ) = o ; I K interdependence: The fo r i.e., forms. probability turbance following parameters, K. E ^u i k U jk^ variable, K^/N^, = ® ^or ^ is m e a s u r e d without error. Considering (i), (ii), (iii) d oe s is since not not mates. and (iii) the a b o v e are a s s u m e d . fulfilled, affect th e panel the a s s u m p t i o n (iv) households property is likely were ( v ) , the p r e s e n t simplyass u m e s theme as ur ed BLUE. 5 study, the the assumptions assumption of heteroskedasticity of least to be randomly incomes the a b o v e a s s u m p t i o n s , t h e o r d i n a r y tors a r e Though the e x i s t e n c e unbiased The assumption the assumptions, esti­ satisfied, selected. like many areaccurate. least squares As for others, Based on squares estima- 5 T h e a s s u m p t i o n s (ii) t h r o u g h (v) s u f f i c e to e s t a b ­ lish t h a t the l e a s t s q u a r e s e s t i m a t e s a r e B L U E . The a s s u m p t i o n s (ii) a n d (v) a s s u r e the u n b i a s e d n e s s o f l e a s t squares estimators. T h e a s s u m p t i o n (i) s e r v e s to e s t a b l i s h 35 2 . i P'. * i ' i * i (Mi The mate the icoression Before computation zero v a l u e s of S inc e log of least analyzing over is all used the o n e to e s t i ­ hundred the m a i n results, one difficulty It household on a c o m p o s i t e expenditure this c r e a t e s those pairs outcome of part o f the s a m p l e . observations They qive and on no that should not composite be food. problem. for w h i c h information of In the fo o d regarding are the counted as and inco m e 7 Cross Th e e s t i m a t e s for of is the p r o b l e m a computational expenditure the e x p e r i m e n t R e s u l t s of alternative method s h o u l d be m e n t i o n e d . household coefficients squares coefficients zero a r c e x c l u d e d . ^ 2.2. r d i] i t regressions. 0 = this c h a p t e r , values < ordinary Linu n i n e t y - f i v e of 1 if the Sectional of five functional t he Studies constant composite f o r m s, over ter m s foods, thirteen th e based cross on t hr e e sectional an i d e n t i t y b e t w e e n l e a s t s q u a r e s a n d m a x i m u m l i k e l i h o o d e s t i m a t e s and to j u s t i f y s t r i c t l y the use of t, F, a n d z test p r o c e d u r e s . F o r a fu ll d i s c u s s i o n of t h i s p r o b l e m , see E. M a l i n v a u d , S t a t i s t i c a l M e t h o d s of E c o n o m e t r i c s (2nd e d .; N e w York: A m e r i c a n E l s e v i c e , 197 0) , pp. 8 4 -8 6 ; a l s o E. J. Kane, E c o n o m i c S t a t i s t i c s & E c o n o m e t r i c s (New Yor k: H a r p e r & Row, 1 9 6 8 ) , pp. 3 5 5- 5 7. ^Some studies assigned zero o b s e r v a t i o n s of h o u s e h o l d H o u t h a k k e r , op. c i t . , p. 50. 7 Kmenta, op. c i t . , p. an a r b i t r a r i l y low v a l u e for e x p e n d i t u r e ; s e e P r a i s and 337. 36 studies f igu r e ii*1 p r e s e n t e d in Table in p a r e n t h e s e s is t he income mated coefficient. corresponding ferent from economic zero sense, coefficient pensity based this 1 through {1) Mpe income is based level been the dairy the @ indicates is well not known form whereas form some Q 5. is the that is the products, form estimates is bas ed esti­ that the In an the income income mean pro­ coefficient elasticity. might of .0024; on th e the m a r g i n a l income the The significantly dif­ conclusions linear of of s i q n i f i c a n c e . linear (MPC); Table elasticity MPC For based on fats th e elasticity be drawn from the estimates the m e a n of the double-log the form and oils, linear form estimates the m e a n is of .0014; based on the estimates the m e a n of the doubl e - l o g the form .2209. (3) basedon For the elasticity based elasticity f r u it s , linear est imates (4) MPC on The mark error 5. .0038. income is on point, For (2) oj 5% it h a s based standard coefficient the d o u b l e - l o g At ol at to c o n s u m e on Table income Table 1 through For on the form the m e a n of is based .004 3; on vegetables, linear estimates is based the mean of the d o u b l e - l o g the m e a n .0026; on the e s t i m a t e s the of the form of M P C i n co m e is .3388. the e s t i m a t e s mean of the d o u b l e - l o g the form of income is .1988. Q It s h o u l d be n o t e d that t h e s e r e s u l t s , f r o m T a b l e 1 t h r o u g h T a b l e 5, p r o v i d e t h e i n f o r m a t i o n n e e d e d to a p p r o x i ­ mate u t i l i t y funct io ns b y Wald's me tho d. Some preliminary e v i d e n c e on t h i s s u b j e c t is g i v e n in C h a p t e r V. 37 TABLE 1 . — E s t i m a t e s of R e g r e s s i o n C o e f f i c i e n t s f o r D a i r y P r o d u c t s Based on A l t e r n a t i v e F u n c t i o n a l F o r ms Period of 1 "'^ii.nihcr. of Constant Terms T3nr<“,d on T.i ne,ir Ocmi-Log Eoublo-Log 3.878 1 .976 .4 07 1.710 2 .203 .373 3. 7r.Q .5 37 'i ■1 3. 28 0 .7^2 .194 5 3.443 1 .08 2 .257 6 3.114 - .541 .105 7 3.430 1 .575 . 35 6 8 3.125 .4 57 .199 n ?. 055 .684 .204 10 3.157 .729 .18 2 11 3. 365 1 .RB9 .34 9 12 3 . 350 3 .763 .522 11 3. 355 3.611 .506 Mean Remarks: Estimates of I.inea r Income Coefficients Pared nn Eerni- I.oq Dnublo-Loq .00110 {.0008) .00050 (.0005) .0025 {.000°) .003 3 (.0011) .0025 ( .0010) ,0048 ( .0012) .0015 O (.0011) .0034 (.0012) .0029 (.0011) .0030 £.0010) .0020 f.0010) .0026 (.0011) .0015 0 (.0009) .8887 (.4017) .7584 (.3769) .003°^ (.0059) 1.4550 (.4471) 1.3089 £.4167) 2.OR 5 0 (.4618) .9947 ( .4234) 1 .5176 (.4528) ) .34 56 ( . 3945) 1.3760 (.3R90) .8589 (.3448) -.00020 (.0044) .0024 9 (.0060) .06570 (.0423) .0 7940 ( .0420) .00070 (.0006) .1576 (.0542) .1 325 ( .0495) .2041 (.05 3 3) .06919 ( .0517) . 1451 {.0561) .1323 (.0569) .1538 (.0494) ,080 3« (.0422) -.00010 (.0005) .00010 (.0007) .0024 .9GR8 .0938 The mark 0 indicates that the income coefficient is not s i g ­ nificantly different from zero at 5% level of significance. T h e till p e r i o d of time i m p l i e s s tudy, s i n c e a c r o ss s e c t i o n a l p e r i o d of time. the t cross study belongs s e c t i on a l to a particular- 38 TABLE 2. Period of Time E s t i m a t e s of R e g r e s s i o n C o e f f i c i e n t s O r i s B a s e d on A l t e r n a t i v e F u n c t i o n a l Intimates of Constant Terms Based on Linear Pemi-Loq Doublc-Log 1 .901 -.210 -.545 *- ].020 -.09] -.097 T .°04 1.077 -.07? 4 .627 -1.034 -.79'. 5 .855 -.704 -.682 r, .712 -.706 -.057 7 .830 .004 -.49 7 8 .773 -.509 -.756 9 .719 -.305 -.051 10 .835 -.025 -.484 11 .750 -.028 -.690 12 .760 1.052 -.070 13 .852 1.037 -.00? Mean Remarks: for F a t s Forms and Estimates of Income Coefficients Bared on Li near .Semi-Log Double-Log .0009 f.0004) .0007 (.0002) .00079 f.0004) .0028 (.0005) .001 7 (.0004) .0020 (.0005) .0007 9 (.0004) .0017 (.0005) .0016 (.0004) .0011 (.0004) .00] 5 ( .0004) .0018 (.0004) .0010 {.0004) .5953 (.1997) .nr r,7 (. 1607) - .00209 (. T077) .ri970 (.1925) .868 3 (.1963) .81 74 (.2032) .4490 (.1854) .7334 (.1885) .6037 ( .1709) .4900 (.1 706) .57 28 (.1642) .0021? (.0020) -. 0 0 4 1 o (.0028) .2279 (.0592) . 216° (. 0 C8 V) -,000 9 0 f.0006) . 3486 (.0627) . 3039 (.0652) . 36 28 (.0734) .1739 (.0750) .3202 ( .0733) . 3441 (.0730) .1899 ( .0617) .28 12 (.0591) .0011? (.0007) -.0014 0 ( .0009) .0014 .5382 .2 209 The mark @ indicates that the income coefficient is not significantly different from zero at 5*. lu:vel of significance. Thu t— p e r i o d of tim<> i m p l i e s s tudy, s i n c e a c r o s s s e c t i o n a l p e r i o d o f time. the cross study belongs sectional to a p a r t i c u l a r 39 TABLE 3 . — E s t i m a t e s of R e g r e s s i o n C o e f f i c i e n t s for F r u i t s Bused on A l t e r n a t i v e F u n c t i o n a l Forms Period of Time Estimates of Constant Terms Based on Li near Semi-Ixjg Double-Log ) 1.459 -1.649 -, 616 2 1 .867 -2.117 -.533 3 1 .794 2.119 .229 4 1 .362 -1.800 -. 609 5 1 .517 -2.533 -.917 6 1 .593 -2.251 - .703 7 1 .958 -2.313 - .680 8 1.402 -3.776 - .896 9 1 .531 -2.420 -.817 CO V in -1.221 - .506 1 .389 -1.127 -.552 12 1 .752 2 .156 .230 13 1 .694 2. 279 .244 10 11 Mean Remarks; Estimates of Income Coefficients Based on Double-Log Semi-Log Linear .0029 (.0007) .0021 (.0005) .0020 (.0007) .0046 (.0008) .0051 (.0009) .0050 (.0010) .0054 {.0012) .0075 (.0011) .0058 (.0010) .0048 (.0009) .0049 (.0009) .0025 (.0009) .0034 (.0009) .0043 1.6923 {.3326) 2.0468 (.3724) .00570 (.0048) 1.8 399 (.3542) 2.2980 (.3611) 2.1390 (.396 2) 2.4292 {.4546) 2.9988 (.4403) 2.304 3 (.3863) 1.6702 (.35 20) 1 .5710 (.3218) .002 30 (.0037) -.00189 ( .0061) 1.6153 .3718 (.0737) .3605 (.0756) .00180 (.0010) .3887 ( .0753) .5518 (.0774) .4594 (.0779) .4775 (.0814) .5586 (.0807) .5058 (.0858) .3594 (.0737) .3675 (.0737) .001 7 (.0007) -.0006 {.0010) .3 388 The mark 0 indicates that the income coefficient is not sig­ nificantly different from zero at 5% level of significance. T h e t-^- p e r i o d of time impl ies the t ^ - c r o s s study, since a c r o s s s ec t io na l s t u d y b e l o n g s p e r i o d o f time. s ec tio na l to a p a r t i c u l a r 40 TABLE wmm I ml 4.— •m m m Period of Time E s t i m a t e s o f R e g r e s s i o n C o e f f i c i e n t s for V e g e t a b l e s Based o n A l t e r n a t i v e F u n c t i o n a l F o r m s - v Estimates of Constant Terms Based on Linear Semi-Log Double-Log 1 1. 779 -.392 - .211 2 1.980 -.506 -.227 3 1.864 2.164 .260 4 1. 599 -1. 243 -.313 5 2.069 -1.236 -.289 6 1.959 -.176 -.162 7 1.864 -.549 - .277 8 1. 579 -1.328 -.416 9 1.432 -.629 -.354 10 1 .548 -.049 -.232 11 1 .476 - .521 -.351 12 1 .628 2.023 .224 13 1.640 1.850 .180 Mean Remarks: Estimates of Income Coefficients Based on Linear Semi-Log Double-Log .0024 ( .0006) .0013 {.0004) .0019 (.0006) .004 2 (.0008) .0036 (.0009) .0028 (.0008) .0029 (.0010) .0039 {.0008) .0027 (.0007) .0021 (.0007) .0028 (.0007) .0024 (.0007) .0012 {.0006) .0026 1.2070 (.3058) 1.2793 (.3061) .00240 (.0045) 1.6580 (.3454) 1.8400 (.3594) 1.2149 (.3252) 1.3650 (.3545) 1.6651 (.3067) 1.1850 (.2615) .9197 ( .2667) 1.1742 ( .2289) .00420 (.0030) .00190 ( .0042) 1.0397 .2257 (.0562) .2371 (.0551) .00030 (.0009) .2805 (.0604) .3034 (.0578) .2277 (.0560) .2699 (.0603) .3213 (.063B) .2552 (.0651) .1982 (.0664) .2639 (.0569) .00120 (.0006) .00020 (.0009} .1988 The mark @ indicates that the income coefficient is not significantly different from zero at 5% level o f significance. th tli T h e t- "- period of time implies the t— cross sectional study, since a cross sectional study belongs to a p articular period of time. 41 TABLE 5 . - - E s t i m a t e s of R e g r e s s i o n C o e f f i c i e n t s for Based o n A l t e r n a t i v e F u n c t i o n a l F o r m s Period of Time Estimates of Constant Terms Based on Linear S e m i - L o g Double-Log 5.993 -5.586 .134 5 .984 -15.359 .133 3 A. 167 7 . 382 .806 4 5 .792 -4.034 .14R 5 5.621 -6.806 .050 6 6 .74B - .295 .308 7 5 .011 -7.032 .142 8 5. 371 -3.654 .070 9 5.447 -2.720 .149 10 6. 179 - .440 .330 11 5 .499 -2.293 .235 12 6. 79 3 8 .128 .845 13 6. 7B1 7 .799 .827 1 Mean Remarks: Meat, Etc. Estimates of Income Coefficients Based on Linear Semi-Log Double-Log .0112 (.0022) .0125 {.0036) .0077 {.0018) .0125 ( .0023) .0157 (.0026) .0075 (.0022) .01 73 {.0035) .0129 (.0023) .0109 (.0021) .0095 (.0023) .0138 (.0022) .0083 (.0024) .0060 {.0022) 6.3161 (1.0157) 11.0688 (2.5591) .00320 (.0124) 5.5704 (.9136) 7.0562 (1.0665) 3.6459 (.8532) 1.9938 (1.3370) 5.2173 (.8841) 4.6853 (.7671) 3.8448 (.8519) 4.7586 (.7477) .0213 {.0099) -.00090 (.0145) .3285 (.0503) . 3232 (.0566) - .00000 ( .0008) . 3202 (.0585) . 3723 {.0568) .2403 (.0563) .3127 (.0614) .3446 (.0628) .3021 {.0612) .2345 {.0531) .2783 ( .0490) .0019 (.0006) -.00020 (.0008) .0112 4.1678 .2353 The mark @ indicates that the income c oefficient is not significantly different f rom zero at 5% level of significance. T h e t— p e r i o d of time i m p l i e s study, s i n c e a c r o s s s e c t i o n a l p e r i o d o f t im e . the t— cross study belongs sectional to a p a r t i c u l a r 42 (5) MPC based on elasticity 2.3. For the linear estimates Income estimates for alternative ring to income based the five the estimates elasticity etc., mean of the m e a n on double-log th e of the the estimates income form is .2353. Estimates Table composite forms, of 5, the foods, income based can easily income estimates functional the .0112; 1 through functional alternative is Elasticity F r o m Table meat, be coefficients are computed three derived. at m e a n v a l u e s , form s , on elasticity Refer­ (S^'s) , the based as on th e s e follows: 9 L i n ea r: Semi-log: ^k2^Yk Double-log: whore M is the sample disposable Y^ is the mean of income sample expenditure at mean on the a period of the th k— the household of time, household food at per c a p i t a pe r a period capita of time, and 1s are j . the For Appendix The F. based income on a l t e r n a t i v e each composite at m e a n 9 of coefficients for the functional f o r ms . L. food, mates estimates values, values of based foo d, on _ „ Y. , M, the three income elasticity alternative _ _ a n d M/Y. are esti­ functional set out in of 43 forms, are widely d i f f e r e n t . ^ tently g i v e s the h i g h e s t The income elasticity double-log The income elasticity estimates form a r e fairly stable s e c t io n al signs of studies. the alternative To estimates income clarify at mean Figure also the values are graphically which an d based different cross studies, based on the three different. the income elasticity composite for m s, 10. over linear sectional for e a c h functional the estimates analysis, are These based separately income presented food, on set o u t elasticity esti­ in F i g u r e 1 through 5. 2.3.1. presentation p roducts, given cross forms through Table 6 mates a r e some elasticity functional three a l t e r n a t i v e in Table In on estimates from on the l i n e a r based form consis­ are v e r y d i f f e r e n t forms. those semi-log Dairy of based in T a b l e The on 6 three an d gives for e a c h p e r i o d The of the time values elasticity alternative Figure first point consistently periods. the i n c o m e P r o d u c t s .- - T h e to estimates functional and a graphical fo r d a i r y forms, are 1. notice highest except based values on is that income for the the the semi-log elasticity 3— semi-log , 12^-, form estimates and 13^- form widely ^ T h e d i f f e r e n c e s between the income e l a s t i c i t y e s t i m a t e s a r e g r e a t e r w h e n e s t i m a t e d at a n y p o i n t a w a y f r o m the mean, s i n c e e a c h f u n c t i o n a l f o r m m a k e s d i f f e r e n t a s s u m p t i o n s as to the w a y in w h i c h t h e e l a s t i c i t y v a r i e s . For a n u m e r i c a l i l l u s t r a t i o n of t h i s p r o b l e m , s e e P r a i s and H o u t h a k k e r , op. c i t ., p. 94. 44 TABLE 6 . - - I n c o m e E l a s t i c i t y E s t i m a t e s for D a i r y P r o d u c t s Based on A l t e r n a t i v e Functional F o r m s (at M e a n V a l u e s ) Period of Ti m e 1 2 3 4 5 6 7 8 9 10 Semi-Log . 0 4 59 0 . 0 2 15 0 . 1048 . 1 335 .0993 .2302 .1995 .0 0 1 0 ^ .38 28 .3417 .06570 .07940 .000 3 0 .1576 .1325 .1881 . 0 61 0 0 .1430 .1251 .1305 .54 15 .27 2 5 .4146 .38 44 .3822 .2041 .06910 .1451 .1323 . 15 3 8 .0793 .1097 . 07 0 2 0 11 12 13 . 1009 .0015 Mean S. D. Remarks : Linear .2353 - . 0 0 0 0 0 Double-Log .08030 - . 0 0 0 1 0 .0006 . 0 0 0 1 0 .26 0 4 .0265 .0938 .0035 The m a r k 0 i n d i c a t e s t ha t the in co me e l a s ­ t i c i t y (or the c o r r e s p o n d i n g i n c o m e c o e f f i c i e n t ) is n ot s i g n i f i c a n t l y d i f f e r e n t f r o m z e r o at 5% l eve l of s i g n i f i c a n c e . S.D. = Standard Deviation _. ^ th . . th cross The t— p e r i o d o f time i m p l i e s t h e t — s e c t i o n a l s tu d y , s i n c e a c r o s s s e c t i o n a l s t u d y b e l o n g s to a p a r t i c u l a r p e r i o d of t i m e . 45 In c o m o K *it i in.1 1 c s \ Semi-log ^ / / V ■Doublo-log V T T 0 2 1 4 5 ]>tir Figure i oil T T (> 7 o1 T im e 'T 9 9 10 11 12 1 3 1.--A G r a p h i c P r e s e n t a t i o n of Income E l a s t i c i t y E s t i ­ m a t e s for D a i r y P r o d u c t s B a s e d o n A l t e r n a t i v e F u n c t i o n a l F o r m s (at M e a n V a l u e s ) 46 fluctuate and other tw o forms. mates based deviation are on is very different The mean of the semi-log from the is those income .2604 and based on the elasticity e sti­ the standard .0265. Secondly, the e s t i m a t e s b a s e d on the s e m i - l o g a n d L the 1 2 — pe riod are negative, w h e r e a s i- double-log forms the e s t i m a t e at based Thirdly, the d o u b l e - l o g v er y nearly on the except and equal linear periods over l i n e ar f o r m arc of time. form is oils, based valu e s, are of on and based Fats income shown the different values based 3E l a n d based on 1 2 — the the same estimates over the e s t i m a t e s standard estimates functional forms noticed that , e x c e p t for elasticity those the periods linear semi-log f o r m are two double-log are n e ga ti ve , whereas positive. on is for the .0015. values and a graphical fats a n d at m e a n the The fluctuate the other on 2. estimates. and are based based 3El, form c o n s istently form w i d e l y based on that different deviation and O i l s . - - T h e semi-log periods, time. Figure the 13— estimates 7 and semi-log on of the , and in T a b l e income from , 12 — give elasticity alternative t ll on the — is p o s i t i v e . elasticity reasonably .1009 13c±L p e r i o d s , the h i g h e s t periods form 3 forms The mean of It w i l l be and the income 2.3.2. presentation for linear F o u r t h l y , the the linear The gives values and are very forms. forms the 12 — The at the estimates linear and , TABLE 7 . - - I n c o m e E l a s t i c i t y E s t i m a t e s for F a t s a n d O i l s B a s e d o n A l t e r n a t i v e F u n c t i o n a l F o r m s {at Mean Values) Period of Time Linear Semi-Log . 1365 .0 9 9 7 .1079G .403 3 .2311 . 5724 .7 6 6 9 -.0019(3 .944 7 .7 8 2 2 .2279 . 3169 -.00090 . 3485 . 3039 . 2936 .111313 . 2528 .2 5 0 2 .1725 .8 0 9 3 .4776 . 712 0 .6354 .4900 .3628 .1739 . 3202 .3441 . 1B 9 9 . 5844 .2812 . 0 0 2 0 0 . 0 0 1 1 0 13 .2223 . 27 3 3 . 1638 - .00390 -.00140 Mean S .D . . 2091 . 00 6 5 .521 7 .0997 . 2209 .0169 1 2 3 4 5 6 7 8 9 10 11 12 Remark s : Double-Log T h e m a r k 0 i n d i c a t e s t h a t the i n c o m e e l a s t i c i t y (or t h e c o r r e s p o n d i n g i n c o m e c o e f f i c i e n t ) is n o t s i g n i f i c a n t l y d i f f e r e n t f r o m z e r o a t 5% l e v e l of s i g n i f i c a n c e . S .D. = Standard De vi a t i o n The t— p e r i o d o f ti m e i m p l i e s the t — cross s e c t i o n a l study, s ince a c r os s s e c t i o n a l s t u d y b e l o n g s to a p a r t i c u l a r p e r i o d of time. 48 Tn come K 1 ,v: I 1 •' i t y r. s t i m a t o s r\ 9 I \ ^ s R ' / si'Dii-loq \ i A . / \ \ / \ / V x A V \ \ . D o u b l i* - 1 o y V-" Li near 1 Period Figure - • f. ■1 of ~T~ 7 1■- 1 b 9 ‘t JO 1 11 ‘n 12 1— 11 Tim e 2.--A Graphic P r e s e n t a t i o n of Income E l a s t i c i t y E s t i ­ m a t e s for F a t s and O i l s B a s e d o n A l t e r n a t i v e F u n c t i o n a l F o r m s (at M e a n V a l u e s ) 49 double-loa are v e r y nearly periods. linear, for m s and equal except for forms .0997, arc would c l a i m forms the and income form are income elasticity and 3. in T a b l e One 8 can time quite forms. Both th e double-log on semi-log the 3^-, the s e m i - l o g fr o m non-linear estimated linear for give the income forms form gives than at income unity. the based of a graphical fruit s , values, based are set form consistently 12^-, based and at e a c h 13— periods. fluctuate on the o t h e r two negative estimates at 3— , 12^^., very close and 13^- base d on to e a c h the other. i. y. 5-^- a n d elasticity The mean for elasticities are and estimates 4- higher One different form w i d e l y those forms Except In a d d i t i o n , log and d o u b l e - l o g values at m ean elasticity for different and the income period. periods, that except based and are Figure see highest The v a l u e s 13— .2209, income e l a s t i c i t y over estimates out the 1 3 - semi-log, and estimates same F r u i t s . --The forms of on the respectively. elasticity functional period linear, the , and .2091, of that time. of the based .5217, .016 9 , on a l t e r n a t i v e gives estimates 3— ., 12 — deviation almost 2.3 .3 . entation are semi-log, .0065, the the the e s t i m a t e s standard on tha t linear of of The based periods elasticity double-log estimates the inco m e The m e a n respectively. on give 8 — periods, estimates the income the that a r e elasticity semi­ pres­ 50 TABLE 0 . - - I n c o m e E l a s t i c i t y E s t i m a t e s for F r u i t s B a s e d on A l t e r n a t i v e F u n c t i o n a l F o r m s (at M e a n Values) Period of Time Linear 1 2 4 5 6 7 0 9 10 Semi-Log Double-Log . 2396 .1554 . 1499 . 3309 .3304 .8768 .9261 .0026(3 .8845 1.1003 .3718 .3605 .0018 .3887 .5518 . 3200 . 2899 .4526 . 3665 . 3287 .9063 .8801 1.1668 .9561 .7230 .4594 .4775 .5586 .5058 .3594 13 . 3301 . 1856 . 2525 -.00070 .3675 .0017 -.00060 Mean S.D. . 2889 .0041 .7052 .1753 .3388 .0376 11 12 Remarks: .7445 0 . 0 0 1 0 0 The m a r k @ i n d i c a t e s t h a t the i n c o m e e l a s t i c i t y (or the c o r r e s p o n d i n g i n c o m e c o e f f i c i e n t ) is n o t s i g n i f i c a n t l y d i f f e r e n t f r o m z e r o at 5% lev el of s i g n i f i c a n c e . S.D. = Standard Deviation th _ . th The t p e r i o d o f t i m e i m p l i e s the t— cross s e c t i o n a l study, s i n c e a c r o s s s e c t i o n a l s t u d y b e l o n g s to a p a r t i c u l a r p e r i o d of time. 51 1n c otno !" 1 n r 1' i r -1 ty 1 < * in.it r'; i 0 R 6 Doulili'-lcg - 4. 1 0 ] 3 I’ u r i o d Figure 7 6 of 3.— A Graphic Presentation mates for Fruits Based F o r m s (at M e a n V a l u e s ) 8 0 1 0 1 1 1? 13 T i me of Income Elasticity E s t i ­ on Alternative Functional 52 estimates based forms 0.7052, are standard on the the and semi-log, 0.2889, deviation semi-log, .0041, that on of income linear, .0376, and income elasticity form are fairly stable bles, based values, elasticity The periods on income elasticity alternative given in T a b l e 9 and The first point to notice form c o n s i s t e n t l y gives the of ti m e The e s t i m a t e s and a r e other except based considerably two for on except the d o u b l e - l o g t hat very nearly Thirdly, on 0.4768, the for and — , the values forms — linear and for a graphical vegeta­ at m e a n 4. that 12 from the semi-log , and at each 13— periods. form widely fluctuate those based on , 12 — , and 1 3 - the semi-log, forms Lastly, the standard on .0003, income linear, 0.1988, .1064, 3— give estimates equal. the m e a n o f based the linear and are 3 on estimates semi-log 0.1885, ity e s t i m a t e s forms the the is indicate time. Figure highest different periods, based .1753, are forms. Secondly, are forms estimates functional are period based based of The estimates V e g e t a b l e s .- - T h e of double-log results estimates over an d respectively. and d o u b l e - l o g the presentation 0.3388, respectively. 2 .3. 4 . linear, the and elasticity and d o u b l e - l o g estimates forms are respectively. deviation semi-log, .0118, of income linear, and respectively. elastic­ double-log One 53 TABLE 9 . - - I n c o m e E l a s t i c i t y E s t i m a t e s for Based on A l t e r n a t i v e F u n c t i o n a l {at M e a n V a l u e s ) Period of Time Linear Semi-Log Vegetables Forms Double-Log . 1765 . 09 6 8 .1391 . 2870 . 206 3 .5587 . 584) .0 0 1 1 ^ . 7368 .6996 .2257 . 23 7 1 .00030 .2 8 0 5 . 3034 . 1774 . 18 4 7 . 2753 . 2198 .1740 .5104 . 5934 . 7638 .6405 . 4866 .2277 .2699 .3213 .2 5 5 2 .1982 .6212 .2 6 3 9 . 0 0 2 0 0 . 0 0 1 2 0 13 . 214 5 .1885 . 10 8 7 . 0 0 1 0 0 . 0 0 0 2 0 Mean S.D. .1885 .0 0 0 3 . 476 8 .1064 .1988 .0118 1 2 3 4 5 6 7 8 9 10 11 12 Remarks: T h e m a r k 0 i n d i c a t e s t h a t the i n c o m e e l a s t i c i t y (or t h e c o r r e s p o n d i n g i n c o m e c o e f f i c i e n t ) is n o t s i g n i f i c a n t l y d i f f e r e n t f r o m z e r o at 5% lev el o f s i g n i f i c a n c e . S.D. = Standard Deviation T h e t— — p e r i o d of tim e i m p l i e s t h e t — cross s e c t i o n a l study, since a c ros s s e c t i o n a l s t u d y b e l o n g s to a p a r t i c u l a r p e r i o d of time. 54 I 11c;Oi»i; 1:1 a n L i c i I t . t: y i in a L e s \Somi-log 3 0 Double-log 1 3 A P e r i o d Figure G 7 o f T i m e H 9 1 0 1 1 4 . - - A G r a p h i c P r e s e n t a t i o n of I n c o m e E l a s t i c i t y ma te s for V e g e t a b l e s Based on A l t e r n a t i v e F u n c t i o n a l F o r m s (at M e a n V a l u e s ) 1 2 13 Esti­ 55 would on notice the that linear periods of forms and estimates forms highly F is h , presentation e t c . , based values, are would gives the highest 3^-^, 12 — , based are v e r y forms. estimates over based different and of E g g s . --The income elasticity on alt e r n a t i v e functional set out in T a b l e 10 At notice that the semi form c o nsis­ and 13— on 2— estimates periods. and from those are 3— and log form g i v e s estimates that the 3— , 12 — income t he greater At , and 13— on the double-log estimates based double-log forms .5428, The standard estimates based forms .1385, are results are indicate on and the th e the the o t h e r unity of an d linear, .0178, double­ for form gives th e to th o s e income linear, .2353, income form Except semi-log, .2259, income the close of two and negative, linear mean elasticity semi-log are ver y the semi-log, .0011, on except fluctuate negative. The deviation the that ar e that on income 1 3 ^ - periods, form. elasticity tively. based than periods, elasticity estimates The estimates form w i d e l y and 13— periods, that log elasticity th e s e m i - l o g different the income respectively. based stable Poultry, One the gives Meat, for meat, estimates and elasticity 5. tently for are a graphical at m e a n Fxgure income time. 2.3.5. values the and respec­ elasticity an d double-log respectively. elasticity The estimates 56 TABLE 10.— I n c o m e E l a s t i c i t y E s t i m a t e s for M e a t , B a s e d on A l t e r n a t i v e F u n c t i o n a l F o r m s (at M e a n V a l u e s ) Period of Time Linear Semi-Log Etc. Double-Log 1 2 3 4 5 .2299 .2526 .1647 .2478 .2 9 7 8 .8 0 9 7 1.3801 .0 004 0 .7224 .8 7 9 8 . 32B5 . 3232 -.00000 . 3203 . 3723 6 7 8 9 10 . 1532 . 3382 .2694 .2321 .1938 .4 9 4 0 .2 6 3 0 . 70 7 9 .6608 .5012 .2403 . 3127 . 3446 . 3021 .2345 11 12 13 .2663 .162 0 .1293 .6353 .0026 -.00010 . 27 8 3 .0019 - .0 0 0 2 0 Mean S.D. .2259 .0011 .5428 .1385 . 23 5 3 .0178 Remark s : The m a r k @ i n d i c a t e s that the income elu:' v i c i t y (or the c o r r e s p o n d i n g i n c o m e c. it r - ■oient) is n o t s i g n i f i c a n t l y d i f f e r e n t f r o m z e r o at 5% level o f s i g n i f i c a n c e . S.D. = Standard Deviation T h e t— p e r i o d of t i m e i m p l i e s the t— cross s e c t i o n a l study, since a cross s e cti on al s t u d y b e l o n g s to a p a r t i c u l a r p e r i o d o f time. 57 T n c ( i n't e■ Klasticity Estimates ■i 3 1 0 9 H 7 r> 4 D o u b le -lo g 1 0 1 3 1 T o r i oil Figure 9 G <3 f 10 11 12 1 3 T i me 5 . - - A G r a p h i c P r e s e n t a t i o n of I n c o m e E l a s t i c i t y E s t i ­ m a t e s for Meat, P o u l t r y , F i s h an d Eggs Based on A l t e r n a t i v e F u n c t i o n a l F o r m s (at M e a n V a l u e s ) 58 based on periods the of linear elasticity Perhaps on Table estimates lower are 11, periods proceeding, at equal the one one m i g h t the 3— can five , 12— answer influenced below, are f or the one p o s s i b l e foods nearly over different time. Before siderably form are by is composite , and that that the foods households' the income are con­ 132-21 p e r i o d s . the h o l i d a y s se e pre-Easter, ask w h y of 3^-, Thanksgiving, the expenditures year. 12^-21, a n d and From 13^21 Christmas holidays. TABLE Year 1958 1 1 . --The Ac t u a l Days and H o l id ay s W e e k s o f e a c h P e r i o d f o r the Period 1 2 3 4 5 6 7 8 9 10 11 12 13 Month and Date 1-1 to 1 - 2 9 1-3 0 to 2 - 2 6 2 - 2 7 to 3-2 6 3-27 to 4 - 2 3 4-24 to 5- 2 1 5 - 2 2 to 6 - 1 9 to 7 - 1 7 to 8-14 to 9 - 1 1 to 6-18 7-16 8-13 9-10 10-8 1 0 - 9 t o 11 - 5 1 1 - 6 to 1 2 - 3 12-4 to 1 2 - 3 1 I n c l u d e d in t h e Ye ar of 1958 Four Holidays New Years Easter M e m o r i a l Day F o u r t h of July Labor Day Thanksgiving Christmas 59 2.4. D i s t r i b u t i o n a of I n c o m e Elasticity" Estimate's From quency foo ds Table 6 distributions as a whole, through of income based Such d i s t r i b u t i o n s ar c Table 10, o n e elasticity on a l t e r n a t i v e set out can derive estimates functional in T a b l e fre­ fo r f o r ms . 12. TABLE 12 .- - D i s t r i b u t i o n s of I n c o m e E l a s t i c i t y E s t i m a t e s Foods Based on A l t e r n a t i v e F u nctional Forms Range of ...... ,., Elasticities -1 0 . 10 . 20 . 30 to to to to to 0 .10 . 20 . 30 . 40 .40 .50 .60 . 70 . B0 to to to to to . 50 .60 . 70 .80 .90 . 90 1 .00 to to 1.00 2.00 Income Linear Elasticity Semi-Log 8 27 21 7 2 income are Of based lie elasticity greater the would on notice and income the d o u b l e - l o g in the range 5 10 1 4 4 6 13 8 13 20 5 8 6 10 5 2 3 0 to the that the semi-log are rest form, six All form gives negative, in elasticity 0.60. 65 65 that estimates t h a n one, sixty-five Estimates Double-Log 4 3 65 One for the range estimates are negative income three 0 to for and elasticity five that 1.00, foods the rest estimates 60 based on the the range 0 to In foo ds linear form arc on the either inelastic: Engel's Elastic and negative the a nd concentrate in 0.50. summary, based positive nonlinear income functional l a w of are form but for predominantly is c o n f i r m e d . elasticity f o un d , estimates are consumption income forms elasticity estimates they are based on comparatively infrequent. 2.5. A Comparison of F i t " Up tigate gives if to the of R 2 an semi-log the d o u b l e - l o g 3— 11 atte mpt will fit" 13 the coefficient functional Table to that all and c l o s e to zero. values , and a better forms 13— differ periods, "goodness of only used the K 2 slightly where fi t " of the to t h e inves­ uniformly The of d e t e r m i n a t i o n , values noticeable to observations. the be functional form are shows The be m a d e forms It w i l l , 12 — gives of , the c o r r e c t e d determination. tive or "goodness based on a l t e r n a t i v e small "Goodness this point, a better values of of for such —o R . values of — 2 R are based on a l t e r n a ­ except linear for the form o b v i o u s l y observations. T h e c o r r e c t e d c o e f f i c i e n t of d e t e r m i n a t i o n R is used to d e s c r i b e h o w w e l l the s a m p l e r e g r e s s i o n li ne fits the o b s e r v e d d a t a . T hi s m e a s u r e takes into a c c o u n t the n u m ­ ber o f e x p l a n a t o r y v a r i a b l e s in r e l a t i o n to t he n u m b e r o f observations. N e e d l e s s to say, the p u r p o s e o f R is to f a c i l i t a t e c o m p a r i s o n s o f the " g o o d n e s s o f f i t " o f s e v e r a l r e g r e s s i o n e q u a t i o n s t h a t v a r y w i t h r e s p e c t to the n u m b e r of e x p l a n a t o r y v a r i a b l e s a n d t h e n u m b e r o f o b s e r v a t i o n s . For a full d i s c u s s i o n of thi s p r o b l e m , s e e K m e n t a , op. c i t . , pp. 2 2 9 - 3 5 a n d p. 365. 61 TABl.t’ . 13. ■ -V.iluer, of mination) Period of Time R (the C o r r e c t e d a n d n (the N u m b e r Composite Food Linear 1 D a i r y P ro d . Fats & Oils Frui ts Veqetab]es Meat, etc. .002 .011 .051 .03 9 .078 2 D a i r y Prod . Fats & Oils Fruits Vege tables M e a t , etc . 3 C o e f f i c i e n t of D e t e r ­ of O b s e r v a t i o n s ) Based Semi-Log on Double-Log n .014 .028 .084 .050 .120 .005 .048 .083 .052 .131 275 269 270 27 3 275 .000 .0 2 4 .052 .030 .04 0 .01 3 .076 .097 .057 .061 .009 .096 .074 .060 . 105 272 267 270 2 71 270 D a i r y Prod. Fats & Oils Fruits Vegetables Meat, etc. .026 .008 .025 .024 .056 .000 .0 00 .001 .000 .000 .000 .000 .008 .000 .000 2 68 2 63 265 268 265 4 D a i r y Prod. Fats & Oils Fruits Vegetables M e a t , et c. .028 . 103 .093 .079 .095 .034 .08 7 .088 .075 .119 .026 .100 .087 .070 .097 272 267 268 272 268 5 D a i r y Prod. Fats & Oils Fruits Vegetables Meat, etc. .018 .041 . 103 . 054 . 112 .032 .066 . 129 .085 .139 .022 .073 . 157 .09 0 . 136 26 9 26 3 267 269 266 6 D a i r y P ro d . Fats & Oils Fruits Vegetables M e a t , et c . .052 .044 .076 .034 .036 .067 .054 .095 .045 . 060 .048 .081 .112 .054 .060 271 264 268 271 268 7 D a i r y Prod. Fats & Oils F r u i ts Vegetables Meat, etc. .003 .005 .066 .029 .080 .016 .019 .096 .050 .092 .003 .017 . 113 .068 .087 264 248 261 26 0 259 62 '''o]i t. i nued ) Composite Food Linear ^ Based on Semi-Log Double-Log D a i r y Prod. F a t s & Oils Fruits V e g o tables Men t , e t c . .027 .041 . 1 35 .077 . 1 00 .037 .052 . 149 .097 . 114 .021 .066 .15 3 .084 .1 0 0 265 255 259 2C5 262 D a i r y Prod. F a t s & Oils Fruits Vegetables Moat , e t c . .023 .036 .098 .048 .0 B 4 .039 . 043 . 119 .069 .123 .016 .076 .116 .05 2 .0 8 3 262 256 257 261 259 D a i r y Prod. F a t s & OiIs Fruits Vegetables M e a t , etc. .026 .017 .090 .030 .058 .042 .027 .078 . 040 . 070 .032 .032 .082 .029 .0 6 7 259 256 25 3 259 256 D a i r y Prod. F a t s S. O i l s Fruits V e g e t a b l es Meat, etc. .010 .042 .092 .059 . 125 .019 .050 .083 .090 .135 .010 .080 . 114 .074 . 109 257 247 25 1 25 5 254 D a i r y Prod. Fa t s & Oils Fruits Vegetables M e a t , etc. .017 .046 .024 .037 .038 . 000 .000 . 000 .003 .014 .0 0 0 .0 0 6 .017 .008 .035 26 1 258 25 5 261 25 7 D a i r y Prod. F a t s & Oi l s F r u i ts V e g e t a b l es M e a t , etc. .006 .019 . 047 .010 . 024 .000 .004 .000 .000 .000 .000 .0 0 4 .0 0 0 .0 0 0 .0 0 0 26 0 25 0 25 5 25 8 256 The t— p e r i o d o f time i m p l i e s the t — cross s ec tional study, since a cross sec tio na l study b e l o n g s to a p a r t i c u l a r p e r i o d of time . n 63 2 ._5. 1 . Distributions D e t e r m i n a t i o n ■— B e f o r e " g o o d n e s s of alternative Such fit," From T able R based .20. form uniformly These of fit" the that the tc to to to to to of „2 R .02 .04 .06 .08 . 10 .20 would be about R of a , based from on Table 13. 14. notice that forms indicate nonlinear of derived highest values form , to the conclusions in T a b l e functional 14.- - D i s t ributions m i n a t i o n {R^) Forms Range 0 .02 . 04 .06 . OR . 10 one will distributions the d o u b l e - l o g "goodness TABLE forms, 14, any Coefficient distributions are g i v e n gives cannot c l a i m log o r frequency on al t e r n a t i v e 0 to one drawing functional distributions o f Corrected the values of lie in the that no functional _2 R . of form, either uniformly gives range Obviously, the semi­ a better observations. of Co r r e c t e d C o e f f i c i e n t of D e t e r ­ B as ed on A l t e r n a t i v e F u n c t i o n a l Linear V a l u e s of R^_______ ______ Semi-Log Double-Log 13 19 15 5 7 6 20 7 10 8 11 9 20 7 7 8 12 11 65 65 65 APPENDIX DAIRY Fresh A PRODUCTS Milk H o m o q e n i z e d - - V i t . D. Multiple Vitamin Milk H o m o g e n i z e d - - P i n in Regular Pasteurized J er se y or G u e r n s e y Buttermilk Chocolate Skim Milk Sour M il k Egg Nog, etc . Other Milk Cream Canned Cofee C r e a m Whipping Cream Sour C r e a m (Liquid) Evaporated--Unsweetened C ondensed— Sweetoned Canned--Baby Formulas Dried Powdered--Skim Milk Powdered--Whole Milk P o w d e r e d — Baby Formulas Ice C r e a m M i x Sher be t Mix Malted Milk Powder Ice C r e a m H a n d P a c k e d Ice C r e a m P r e - P a c k a g e d Ice C r e a m O t h e r Ice C r e a m S h e r b e t s a n d Ices D a i r y Q u e e n , F r o s t i e , etc. Cheese Natural A m e r i c a n (Cheddar, etc.) P r o c e s s e d A m e r i c a n ( V e l v e e t a , etc.) Swiss C he e s e Cheese Spread C r e a m C h e e s e ( P h i l a d e l p h i a , etc.) Cottage Cheese Other C h e es e 64 APPENDIX FATS B AND OILS Butter Oleomargarine Lard Swiltninq Vegetable Shortening O the r Fats (Cnsco, Oi 1 s C o o k i n g Oils Mayonnaise Salad Dressing Roquefort Dressing S a l a d Oils, et c. F r e n c h D r e s s i n g , et c . Sandwich Spread, Tartar Whips O ther Oils 65 Sauce Spry, e tc . ) APPENDIX C FRUITS Merr i os B l u o b e r r i os C v a n b n r r i os Cu r rants D e w b e r r i e s anc3 B 1 a * k bcr r io ^ Raspberries Strawberries Berry Juice Other Berrios Ci t r u s Other Grapefruit Lemons Lemonade Lemon Juice Gr apef ruit Juice Limes Lime Juice Limeade Oranges Orange Juice O r a n g e D r i n k (Hi-C, etc.) Tangerines Ta n g e r i n e Juice Mixed Citrus Fruits Mix ed Citrus Juice Other Citrus O th er Ci t r u s Juice Fruits Apples A p p l e s a u c e and Apple Butter Apple Cider Apple Juice Apricots Apricot Nectar Avocados Bananas Cherries--Maraschino Cherries--Sour Cherries--Sweet Da tes Figs 66 67 other Fruits ( C ontinued) Grape Juice C a n t a l o u p e a nd M u s k m e l o n Watermelon Nectarines 01 iv e s Persimmons Peaches Pears Pineapple Iineapple Juice Plums Prunes Prune Juice Raisins Rhubarb H a w a i i a n P u n c h Base Mixed Fruits Fruit Cocktail F r u i t Pie M i x Mixed Fruit Juice Fruit Gelatin Salad--Prepared Powdered Juice Candied Fruit Fruit Pickles Other Fruits Other Fruit Juice APPENDIX D VEGETABLES Green I,eafy V e g e t a b l e s Brussel Sprouts Cabbage Cabbage Salad Sauerkraut Celery Cabbage Endive, Chicory, Escaro le G r e e n s - - B e e t , M u s t a r d , etc. Lettuce--Head L e t t u c e — Leaf Lettuce--Bib Parsley, Swiss Chard, Water Cress Spi n a c h Mixed Leafy Vegetables Other Leafy Vegetables Green and Y e l l o w V e g e t a b l e s Artichokes Asparagus Beans--Lima Beans--Snap Bean Sprouts Broccoli Carrots Corn--Sweet Peas Peppers Pumpkin S g u a sh Soy Steak and C h o pl ets M i x e d G r e e n an d Y e l l o w V e g e t a b l e s Others All O t h e r V e g e t a b l e s Beans --N av y, Baked, White Pork and B eans Beans--Kidney Beets Cauliflower Cucumbers Cucumber Pickles Relish Egg Plant G a r 1 ic 68 69 Horseradish Mushrooms Onions--Mature On i o n s - - G r e e n Parsnips Pimentoes Michigan Potatoes Maine Potatoes Idaho Potatoes California Potatoes Other Potatoes P o t a t o e s — F r e n c h Fries Potato Chips Potato Sticks Potato Salad M a s h e d P o t a t oe s or Patties S w e e t P o t a t o e s a n d Yams Rad i s h e s Tomatoes Tomato Catsup To mato Juice T u r n i p s an d R u t a b a g a s Prepared Vegetable Gelatin Salad Mixed Vegetables C h o p Suey, C h o w M e i n , w i t h o u t M e a t Mixed V e g e t a b l e Juice Other Vegetables APPENDIX MEAT, POULTRY, E F I S H , AND EGGS Beef C a n n e d Beef C o r n e d Beef C h i p p e d Beef G r o u n d Beef, H a m b u r q e r G r o u n d R o u n d Steak, L e a n G r o u n d Beef Beef Liver and Baby Beef Liver Heart, Tongue, other O rgan Parts C h u c k R o a s t (Pot R o as t ) Rib Roast Other Roast Round and S w i s s Steak Sirloin Steak P or t e r h o u s e and T- Bone Steak O t h e r Steak S t e w i n g B e e f ( B on e l e s s ) Boiling Beef or Short Ribs All Other Beef Pork Bacon Canadian Bacon C a n n e d Pork Chops Steaks Ham--Center Slice H a m - - W h o l e o r Half Ham--Canned Ham--Other P i c n i c Ham, C u r e d B u t t s Pork Liver Heart, Tongue, other O r g a n Roast--Fresh Sausage--Link Sausage Spax~eribs S i d e or S a l t P o r k O t h e r Pork Lamb-Mutton Chops, Steaks R o a s t (Leg, e t c . ) Other Lamb— Mutton 70 Parts 71 Veal C u t J e t s , Chops, steaks Ground Veal Calf Liver City Chicken Roast Stewing, Soup Veal Other Veal O t h e r Meat and Meat M i x t u r e s W i e n e r s a n d F r a n k s , etc. B o l o g n a — R i n g or L a r g e R o u n d Other Cold Cuts Prem, S p a m , T r e e t , etc. Rabbit, Domestic V e n i s o n and O t h e r Game A n i m a l s Chop Suey Meat and Kabobs Bouillon Cubes Beef Stew Chile Con Carne Hash Mincemeat M e a t B a l l s and S p a g h e t t i Ravioli and Tamales C h o p Sue y , C h o w M e i n w i t h M e a t Potted Meat Meat Spreads Por k a n d B e a n s Others Chicken B r o i l e r s or F r y e r s Roas ters Stewing Barbecued Chicken Turkey Duck Other Poultry Game Birds Mixtures--Chiefly Chicken Chicken Noodle Dinner C h i c k e n a la K i n g C h i c k e n C h o p S u e y , etc. Others F is h and Sea F o od Tuna Salmon Fish Sticks Other Fish 72 Fish Eggs and S e a F o o d ( C o n t i n u e d ) Lobster, Lobstertail Oysters Oys t e r Stew Seallops Shrimps T u n a Pi e or C a s s e r o l e S a r d i n e s in O i l S a r d i n e s in S a u c e APPENDIX VALUES Period oi Tinie Parry Y k , M, y AND M/Yk m k M/Y, K P i cjcU j c ts 1 2 3 4 5 3.86 3.80 3.77 3.8 0 3.83 1 b i .09 163.74 158.17 153.79 152.24 41.73 43.08 41.95 40.47 39.74 6 9 10 3.8 5 3.65 3.6 6 3.5 0 3.60 150.89 148.63 153.95 151.10 156.63 39.19 40.72 42.06 43.17 43.50 11 12 13 3.66 3. 7 6 3.61 144.8 0 158.70 168.99 39.67 42.20 46.81 1 2 3 4 5 1.04 1.13 1. 0 2 1.05 1.11 157 . 81 161.06 157.31 151.25 150.95 151.74 142.53 154.22 144.04 135.99 6 9 10 1.01 .94 1.0 3 .95 1. 0 0 148.29 149.50 153.23 148.59 156.82 146.82 159.04 148.76 156.41 156.82 11 12 13 .98 1.05 1.03 145.30 159.47 168.81 148.26 151.87 163.89 7 8 Fats OF F and O iIs 7 8 73 74 P e r iocf Y, M M/Y. ________ of T i m e _______________ h_____________________________________ lL Frui ts 1 2 3 4 1.93 2.21 2.12 2.08 2.29 159.49 16 3.63 158.9 4 153.29 151.52 82.63 74.04 74.97 73.69 66.16 2.36 2.76 2.57 2. 4 1 2.31 151.44 148.19 155.11 152.33 158.20 64.16 53.69 60.35 63.20 68.48 12 13 2.11 2.15 2.27 145.65 159.64 168.64 69.02 74.25 74.29 1 2 3 4 5 2.16 2.19 2.16 2.25 2.63 158.94 163.24 158.17 153.79 152.24 73.58 74.52 73.22 68.35 57.88 6 9 10 2.38 2.30 2.18 1.85 1.89 150.89 146.53 153.95 15 0.61 156.63 63.39 63.70 70.61 8 1. 4 1 82.87 11 12 13 1.89 2.02 1.85 144.83 158.70 167.62 76.62 78.56 90.60 5 6 7 8 9 10 11 Vege tables 7 8 75 Period of T i m e Meat, y , k M M/Y. 1 etc. 1 2 3 4 5 6 7 8 9 10 H oma rk : 7 . 80 .0 2 7 . 38 7.71 8 . 0 2 16 1.09 162.12 158.00 152.96 152.16 7 . 38 7 . 58 7 . 37 7. 09 7 . 67 150.80 148.23 154.00 151.03 156.59 20.43 19 . 5 5 20 .89 21. 30 20 .41 144.56 158.62 167.90 19 . 30 19.53 21.55 8 11 7.49 12 8 .12 13 7.79 The t — p e r i o d of t i m e i m p l i e s s e c t i o n a l study, since a c r o s s b e l o n g s to a p a r t i c u l a r p e r i o d 20 .53 20 .21 21.40 19 . 8 3 18.97 the t — cross sectional study of time. CHAPTER COMBINED I. combining earlier cross used are cross income sectional in model ferent many the with the regression, several of elast.ici t i c s . As and Prais time since and Engel series used than more cross be General any R e m a rks curves dat a. regression will procedure.* may Some studying estimates successive prices, and ior combined elasticity estimation sets reasons sectional mentioned, reliable STUDIES Objectives There by IV As give more individual observations are Moreover, the sections, or w i t h to e s t i m a t e price Houthakker combined dif­ mention: T h e d e r i v a t i o n of p r i c e e l a s t i c i t i e s . . . h a s b e c o m e p o s s i b l e f o l l o w i n g the c o l l e c t i o n of f a m i l y b u d g e t s o n a c o n t i n u o u s b a s i s for a l e n g t h p e r i o d . The analysis . . . is n o t d i f f e r e n t f r o m t h a t c l a s s i c a l l y a p p l i e d to t i m e s e r i e s , b u t the r e s u l t s r e c ent ly a c h i e v e d using family bu d g e t records appear more successful. T h e c o n s i s t e n c y of the d a t a is p r o b a b l y the m a i n r e a s o n for g r e a t e r s u c ­ c e s s , in t h a t b o t h p r i c e s a n d q u a n t i t i e s are c o l l e c t e d s i m u l t a n e o u s l y , u s i n g p r e c i s e l y the s a m e e o m m o d i t y - d e f i n i t i o n s and m eth od s of o b s e r v a t i o n , and over a lengthy period. *See p. 13, Chapter I. ■^Prais a n d H o u t h a k k e r , o p . ci t . , p. x x v i . The deri­ v a t i o n of p r i c e e l a s t i c i t y e s t i m a t e s F r o m t h e f a m i l y b u d g e t r e c o r d s is a l s o m e n t i o n e d in K l e i n , I n t r o d u c t i o n to E c o n o ­ m e t r i c s , op. c i t . , p. 62, f o o t n o t e 2^~. 76 77 T h o o r e t i c a 1 ly , the is e s s e n t i a l behavior lar for e x p l a i n i n g changes commodity. When commodity is n e i t h e r price unity, the esting for regardless estimate price elasticity to e c o n o m i s t s the good. who engage the U.S. price*?. This may be d o n e of p r i c e inelastic, estimates that estimates on expenditures. instance, lood lower the d e m a n d the same t he than price, When it the the is lower the 3 also be inter­ in e c o n o m i c p o l i c y . are amount When greater government decides parameters a value, and may by p ri ce of a particu­ changes. the is to t a l price and expenditures the is, price for is n u m e r i c a l l y is e l a s t i c , the d e m a n d in the estimate That of elasticities expenditure in a b s o l u t e spent smaller The unity inelastic. tot al unity, to nor elasticity the than price, elasticity the d e m a n d greater less the price price how household to v a r i a t i o n s is e q u a l be of according elastic of m o n e y w i l l the estimation fixing. reliable, the to Assume, raise If the quantity T h e a b o v e s t a t e m e n t c a n be p r o v e d as f o l l o w s : the t o t a l a m o u n t s p e n t for a c o m m o d i t y is g i v e n b y PQ; w h e r e P is the p r i c e , a n d 0 is the q u a n t i t y p u r c h a s e d of the g o o d . T h u s , where dP n is the = Q(1 + n) ; price elasticity = ^ . T h i s e x p r e s s i o n is n e g a t i v e f o r v a l u e s of n b e t w e e n - i" a n d - 1 , z e r o f o r n e q u a l to - 1 , a n d p o s i t i v e for v a l u e s of b e t w e e n -1 a n d zero. T h a t is, t h e t o t a l a m o u n t s p e n t increases, re m a in s constant, or d e c r e a s e s wh en pr ic e d e c r e a s e s ; a c c o r d i n g l y , t h e p r i c e e l a s t i c i t y o f d e m a n d is n u m e r i c a l l y g r e a t e r than, e q u a l to, o r less t h a n , u n i t y . See J. M. H e n d e r s o n a n d R. E. Q u a n d t , M i c r o e c o n o m i c T h e o r y (2nd od. ; N e w Y o r k : M c G r a w - H i l l , 1 9 7 l T ^ p~. 2*7. 78 of the p r o d u c t s be c o n s i d e r e d which are stances, desirable pursued in the d e c l i n e negligible, from demanded the compared increase in e c o n o m i c in can b e or not expected. depending The on economic policy.Under in c o n s u m p t i o n o f with the b e n e f i t prices. policy may be Various results may the social ends certain c i r c u m ­ f o o d s t u f f s is accruing social in c o n f l i c t . to p r o d u c e r s ends pursued Yet, Tintner men- tions: E c o n o m e t r i c s c a n c o n t r i b u t e n o t h i n g as f a r as the c h o i c e of a c o n c r e t e p o l i c y b a s e d u p o n t h e s o c i a l e n d s is c o n c e r n e d . But e c o n o m e t r i c s c a n p e r h a p s c o n t r i b u t e s o m e t h i n g in g i v i n g e c o n o m i s t s n u m e r i c a l e s t i m a t e s of the r e s u l t s of t h e a d o p t i o n of v a r i ­ ous p o s s i b l e p o li c i e s . For sectional curves price us e d As in and will reasons time are taken the and stayed from and T h er e are 212* the th e as returned are 13 = Tintner, be five c o m p o s i t e M.S.U. Consumer fo u r w e e k l y a period of the p a n e l selected 2756 will for e s t i m a t i n g chapter, treated p e r i o d s of t i m e A for previous m e n t i o n e d , ' ’ in se ri es data be m o d i f i e d parameters together that the this chapter, pooled. both The income foods. Panel reports for t he s a m p l e an d d a t a of are Those all of Engel The d a t a reports time. cross 195 8 . grouped households thirteen observations. o b s e r v a t i o n s for e a c h c o m p o s i t e food.*’ o p . c i t . , p. 12. T o e s t i m a t e p r i c e e l a s t i c i t i e s a n d to o b t a i n m o r e r e l i a b l e e s t i m a t e s o f i n c o m e e l a s t i c i t i e s f o r the five c o m p o s i t e foods. that teen ^ T w o h u n d r e d t w e l v e is t h e n u m b e r o f h o u s e h o l d s s t a y e d a n d r e p o r t e d their e x p e n d i t u r e s o v e r all t h i r ­ p e r i o d s of t i m e in ]958. 79 2. by the p r i c e able pooling of the cross foo d in d e t e r m i n i n g Different prices. by Statistical cross Th e Wang sectional concerned household sections M.S.U. will be used loccc by the p a n e l an expenditure series to data, vari­ behavior. sets indices chapter Models important to d i f f e r e n t food p r i c e in t h i s time becomes belong retail and Combined of constructed represent the food 7 prices of tJie fi v e composite In a c r o s s reasonably analysis. quantity ture food °itv. = the price out in where the proper The i^- household quantity tn e t— — periou time indices lb. prices are is usually used regression analyses, to q u a n t i t y computed price Table sectional combined simply These expenditure in a c r o s s for is set study, be c o n v e r t e d purchased by at must are household variable However, expenditure foods sectional constant, as a d e p e n d e n t households. prices vary; purchased. by d e f l a t i n g The expendi­ index. cf purchased is c o m p u t e d as on the k— follows: (yit.k * 1 0 0 ) / P tk th t ^ie i— household where the P ^ is k^ii f o o d the p r i c e period 7 of at the index aggregate t^l period of the expenditure of k^Jl f o o d time, at on and the t— time . H. F . Wang, "Retail F oo d P r i c e I ndex Based M . S . U . C o n s u m e r P a n e l " ( u n p u b l i s h e d Ph.D. d i s s e r t a t i o n , M i c h i g a n S t a t e U n i v e r s i t y , 1960). on 80 'I’M-; f ■Price I n d i c e s of Five M.S.U. C o n s u m e r Panel (1955-57 = 100) Period of Time 1 -> ■1 Da iry Prod . Fats & Oi Is 100 .9 98 . 8 1 0 0 .2 98 .8 98 . 1 101.3 98 . 3 95 .9 97.4 97.9 97 .6 99 .2 98 . 2 6 7 8 o 1 0 98 .2 97 . 7 96.1 1 1 12 13 Source: on Fruits Vege­ tables Hea t, etc. 93.4 105 . 8 1 00. 5 115.4 112.5 115.9 117.5 1 29 . 1 1 36 . 6 1 30. 4 105 .0 107 .4 106 .4 1 1 0 .2 1 1 1 .4 119.6 .8 .4 .3 .4 119.8 11 4 . 5 91 .1 82.5 76.1 113. 7 114 .7 113. 2 Ill .7 I l l .e 97 .6 95.0 96 . 4 85. 2 83.1 82 . 3 1 0 0 .0 100.7 1 0 0 . 1 98 97 97 96 1 1 2 . 2 92.2 3 .5 71.2 7 79 .5 93.8 1 0 1 . 0 109 .6 Ill .6 1 1 0 .0 H . F. W a n g , "R e t a i 1 F o c d Pr i c e Index B a s e d on M . S . U. C o n s u m e r P a n e l " ( u n p u b l i s h e d Ph.D. dissert.i tion, M i c h i g a n S t a t e U n i v c r s i ty , 1960), T a b l e 1 0 , p p . 146-47. Tii this m a n n e r , o n e price multiplied Based Fngel C o m p o s i t e For Is B a s e d D a t a of 1958 curve on for by q u a n t i t y the c e t e r i s ,i the k _ fo od c an notice equaling paribus that the identity expenditure assumption, of is p r e s e r v e d the m o d i f i e d 8 ca n be stated as: O T h i s m o d i f i e d E n g e l c u r v e is s i m i l a r to the th M a r s h a l l i a n d e m a n d f u n c t i o n w h e r e o n l y the p r i c e of the k.bii f o o d a n d per c a p i t a d i s p o s a b l e i n c o m e are a l l o w e d to v a r y a n d all o t h e r p r i c e s are h e l d fixed. Under certain assumptions, M a r s h a l l d e d u c e d the s o - c a l l e d " l a w of d e m a n d , " in w h i c h he s t a t e d t h a t the s l o p e of h i s d e m a n d c u r v e w i t h r e s p e c t to p r i c e is a l w a y s n e g a t i v e . F o r a full d i s c u s s i o n o f M a r s h a l l ' s law of d e m a n d , s e e D. W. K a t z n e r , S t a t i c D e m a n d T h e o r y (New York: M a c m i l l a n , 1970), pp. 58-59, 81 °itv M it “ it w it whore 4 V itV ''tv.' '*'S t ^° household on the k 1^22. f o o d at is the i±£L h o u s e h o l d per the capita t-— consumption period of time, I- L at Engel u .j is the disturbance, t, is the undefined prices Engel curve are defined held gives in the constant, of disposable time, and f u n c t i o n a l form. curve is c o n s i s t e n t w i t h previous chapter. the m o d i f i e d As Engel lon g curve is the as the c u r v e. Regarding curve, the Engel capita th t-— p e r i o d income This m o d i f i e d per since neither a better the thirteen the- Linear the the "goodness cross form functional f o r m of semi-log of fit" sectional is a d o p t e d in nor to this the the studies the in modified double-log En g e l form observations based the chapter, chapter previous as the first on order • « • approxlina t ion . 9 u T h e a d o p t i o n of l i n e a r r e l a t i o n s h i p s is a p r o p e r procedure. As a p p l i e d to th e m e a s u r e m e n t o f d e m a n d o f f o o d in t er n s of p r i c e p^ a n d i n c o m e m, t h i s i n v o l v e s the T a y l o r ' s series a p p r o x i m a t i o n ar ound any g i v e n point 0 o 0 . - q ]:, ni^) or n qk " q k + 3qk 0 o (^ F P ) (m“m 1 + 3qk 0 o (3p“ J (pk " p ' + r e m a i n d e r * As l o n g as t h e p r i c e an d i n c o m e c h a n g e s w e r e s m a l l , the r e m a i n d e r e r r o r t e r m c a n be n e g l e c t e d . S ee P. A. S a m u e l s o n , " S o m e I m p l i c a t i o n s of ' L i n e a r i t y , ' " T h e R e v i e w of E c o n o m i c S t u d i e s , 1 9 4 7 - 4 8 , r e p r i n t e d in T h e C o l l e c t e d S c i ­ e n tific Papers of P. A. S a m u e l s o n ,e d . by J . EL S t i g l i t z T m . 1 .T . P r e s s , 1^6 6 ) , p"! 6 1 . 82 T h u s r the m o d i f i e d expressed as — rr-— + = Ni where Cl■, k R — k U ifc jm a t i o n pooled, of when of periods of relics as s u m m a r y of factors which effect par t, Kmenta that ar e of P, , ar e and + tk the k - ^ food is 1 price i.e. , constant coefficient, fo r probability distribution various time. a on large enter successive obviously that into The the the factors to the cross the term, k^- the disturbance with other common of the sections ca n a r i s e . ^ food. Th e dis­ are existence occurring at disturbances at belief in the a u t o c o r r e l a ­ interpretation of the d i s t u r b a n c e number of no t m e a s u r a b l e . ^ carry over tk is c o r r e l a t e d largely thes e U. , , parameters, implies time tion a k autocorrelation period other Y the autoregression one for Procedure Regarding turbance- + y. coefficient, 2.1. curve follows: uv , R , and income Enael random and relationship Then independent under one w o u l d operating in one following periods. study, suspect period As but that would, in Professor mentions: A u t o r e g r e s s i o n o f the d i s t u r b a n c e s c a n be c o m p a r e d w i t h the s o u n d e f f e c t of t a p p i n g a m u s i c a l s t r i n g : w h i l e the s o u n d is l o u d e s t a t the t i m e o f i m p a c t , it *°Kuh, o p . c i t . , p. 98. ^ F o r a full d i s c u s s i o n J o h n s t o n , o p . c i t . , pp. 177-99. of autocorrelation, see the 83 d o e s not s t o p i m m e d i a t e l y but l i n q e r s o n for a t i m e u*:tii :t f i n a l l y Hi e s off. T h i s m a y a l s o he the c h a r a c t e r i s t i c of the d i s t u r b a n c e , s i n c e its e f f e c t m a y lin g er for some t i m e a f t e r its o c c u r r e n c e . But w h i l e the e f f e c t of o n e d i s t u r b a n c e l i n g e r s on, o t h e r d i s t u r b a n c e s ta k e p l a c e, as if th e m u s i c a l s t r i n g w e r e t a p p e d o v e r a n d over , s o m e t i m e s h a r d e r t h a n at o t h e r times. The .shorter the ti m e b e t w e e n t h e t a p p i n g s , the g r e a t e r the l i k e l i h o o d t h a t the p r e c e d i n g s o u n d ca n s t i l l be h e a r d . S i m i l a r l y , the s h o r t e r the p e r i o d s of i n d i v i d u a l o b s e r v a t i o n s , the g r e a t e r the l i k e l i h o o d of e n c o u n t e r i n g a u t o r e g r e s ­ sive d i s t u r b a n c e s . In r e c e n t how to cope w i t h Most of of the w ill y ea r s , the a u t o c o r r e l a t i o n the p r o p o s e d corrections variance-covariance s e l d o m be This s t u dy , The d i s t u r b a n c e wil l be of order and first the v a l u e s characterized (ii) Zero m e a n : E (u itk^ Homoskedasticity: 13 upon as assumes exact that autoregressive of which the scheme. the e x o g e n o u s vari­ is n o r m a l l y d i s t r i b u t e d ; = 0; 2 E ^U itk^ o p . c i t ■ , p. on knowledge fo l l o w s : 2 = °k; i n t e r d e p e n d e n c e :E ( U . ,U. , ) = ltk jtk Kmenta, literature the d i s t u r b a n c e the U • No depend others, Normality: (iv) of has b e e n a c c u m u l a t e d . like m a n y (i) (iii) matrix body 13 kno w n. au to c o r re la ti o n has ables a substantial 0 for i ^ j; 270. K u h , o p . c i t . , p. 99. For a rec en t survey of l i t e r a t u r e o n tKe s p e c i f i c a t i o n of a u t o r e g r e s s i v e s c h e m e , see G. T i n t n e r a n d J. K. S e n g u p t a , S t o c h a s t i c E c o n o m i c s (New York: A c a d e m i c Pres s , 1972), pp. 12-21. 84 *v' Firr^ order autoregression: ^ E < u it-]kv jtk’ = (vi) The e x o g e n o u s Vf'P t 1 Ml I 1 least sauarcs <*o n s ist en t , yet mal e s they nsymptotica1 two-stage Orcntt wiH (1 ) A p p l y of From 1 os a re th e 0 error. ) , tlie c o n ­ u n b i a sod o f f ici e n t of without ^ (f,k and a sympt o l ical nor least 1 1 y s q u a res os t i - an d can be these 14 1 S used to consists th e least (i.e., asymptotically suggested the of the squares t )l k-rii food. coefficients calculate residuals, For method at least, consis­ normal), by C o c h r a n e and 15 for regression tha t , y efficient, used. curve estimates properties estimation be the asymptotical ^ho o r d i n a r y Engel th e and j; are m e a s u r e d variances The p r o c e d u r e fied not to o b t a i n the d e s i r a b l e tent, the *• .are b i a s e d . ^ In o r d e r have a11 cot re 1 at ion estima are A n d , th e efficient. £or variables is s o r i a 1 T f th e r e 0 U . , . = nv U. , +V. . ; lit'. K lt'lK ] tk are the following method The * regression t he the m o d i - resulting unbiased 3 to two s t a g e s : and * estimates consistent, residuals one can obtain estimate proofs, see K m e n t a , o p . c i t . , p. of U ., , . i tk by 269-97. S e e D. C o c h r a n e a n d G. H. O r c u t t , " A p p l i c a t i o n of L e a s t S q u a r e s R e g r e s s i o n s to R e l a t i o n s h i p s C o n t a i n i n g A u t o c o r r e l a t e d E r r o r T e r m s , " J o u r n a l o f the A m e r i c a n S t a ­ t i s t i c a l A s s o c i a t i o n , Vol . 44 ( M a r c h , 19 49) , p p . 32-61; K m e n t a , o p . c i t . , pp. 2 8 7 - 8 8 a n d pp. 5 0 9 - 1 2 . 85 °k 212 13 l-l 2T 2 t= 2 13 . 1 where of =] r= 2 212 is V .t , U . it!; u lk . U it-lk the n u m b e r of h o u s e h o l d s , and 13 is the number periods. IF* Obviously, (2 ) r-ing the p^ pv to is a c o n s i s t e n t transform estimator of . the o b s e r v a t i o n s : ° t t k = "k + "kM i t + v k p * k + u *tk where ° i tk ■ °itk/ N it - ek ° i t - i k / N it-i M *t ■ M u /Ni t - K - p tk ^itk i = 1 t = 2, The regressive. again, ~ ^itk the , 2 p t-ik K p k U it- lk , 3, . . . , 2 1 2 ..., disturbance Applying estimators 13. Uf *lK is a s y m p t o t i c a l l y the o r d i n a r y of a*, K . asymptotic properties; i.e., efficient, and a s y m p t o t i c a l l y p K least , and y. K consistent normal. nonauto- squares have method the d e s i r a b l e asymptotically 86 2 .2. R e sults At ting the of th e Combined first stage autoregressive estimates of regression Studies of computation, effects, the coefficients without least are elimina­ squares obtained as foilow s : bn 1 ry Pt od u c t s : q., = 4.0498 11 1 = S = Fats and Oils: q + .00 1 7 m-. , it (.0003) + .0 0 1 1 m . . - .0057 P (. 0 0 0 1 ) (.0086) U + .0 0 3 9 m- .0215 P (.0002) C (.0023) xt Frui t s : .0 2 0 7 .8 6 0 9 q. = 3.8473 lfc R2 = .0058 P. t ( .0217) .0112 1.8163 = 1.4148 R2 = S = - .0854 S = 1.8020 Vegetables: q. = 3.1244 + lt: R2 = S = M e a t , e t c .: q . = R2 S = where q.. at = m it — 2 R it it . 0 0 2 3 m. - (.0 0 0 2 ) .01 3 3 P. (.0 0 1 1 ) .0 7 8 7 1 . 3354 12 . 2750 + . 0 0 8 9 m. . (.0006) lt: .0621 P t (. 0262) . 0699 3.7902 ; M. . / N . . it is it the c o r r e c t e d S is t h e standard coefficient error of of determination; estimate. and B7 Using cients, the the e s t i m a t e s the fiv e are presented composite in to b u t less .6629, and cifnts for d a i r y and meat, .8284 resulting than .50 3 1 of foods regression 16. one. The They are figures products; fats products, and all .8284, the e s t i m a t e s of These for estimates positive, .6966, close .7100, autocorrelated and oils; The highest the coeffi­ coefficients are c a l c u l a t e d . etc. , r e s p e c t i v e l y . fo r d a i r y of autocorrelated Table are estimates lowest fruits; is coeffi- vegetables; estimate .5031 is for me a t , etc . TABLE 15. E s t i m a t e s of A u t o c o r r e l a t e d Five Com p o s i t e Foods Foods Dairy Fats Estimates of Autocorrelated Products and Coefficients Oils .6966 .7100 Vegetables .66 Mea t, .5031 etc. Statistically, coefficient for figure is c l o s e the relationship the positive f or a p a r t i c u l a r disturbances which Coefficients .8284 Fruits ted for that food ar e to o n e between 29 estimate food indicates positively indicates of that the correlated. that the d i s t u r b a n c e s autocorrela­ is t^e degree fairly The of high. 88 At gressive the final effects staqe of co m p u t a t i o n , are e l i m i n a t e d . regression The least squares of foods are obtained TABLE 1 7 . - - E s t i m a t e s of R e g r e s s i o n C o e f f i c i e n t s for F i v e C o m p o s i t e F o o d s a f t e r E l i m i n a t i n g the A u t o r e ­ gressive Effects Constant Te r m Food s Dairy Fats Products and shown in fo r autore­ estimates and coefficients the Table the fiv e composite 17. C o e l.f . Price Coe ff . 1 . 5 01 1 .0 0 0 4 { .0 0 0 2 ) -.0553 (.0 2 0 0 ) .0038 1.0029 .7698 .0006 (. 0 0 0 1 ) -.0165 ( .0066) .0104 .5589 Oils 1 ncom.e S R2 F r u i ts 1 .1656 .0 0 2 7 (.0003) -.0200 ( .0025) .0494 1.2784 Vegetables 1. 16 0 0 .0 0 0 7 (. 0 0 0 2 ) -.0147 (.0016) .0318 .9 8 7 2 Meat, 4 .0680 .0 0 6 3 (.0007) - . 0 2 2 1 0 .0262 3 . 12 6 3 etc. Rema r k a ■ T h e m a r k @ i n d i c a t e s t h a t the r e g r e s s i o n c o e f f i ­ c i e n t is not s i g n i f i c a n t l y d i f f e r e n t f r o m z e r o at 5% l e v e l of s i g n i f i c a n c e . R 2 is S is t he the From Table mates are of income positive level income of (.0395) and corrected standard 17, one coefficient error would coefficients fo r coefficients a re Needless more determination. of e s t i m a t e . notice the to that five significantly different significance. of say, reliable all the composite from these than esti­ foods z e r o at 5% estimates those of estimated 89 from individual tions are used As five for composite meat, etc., cantly cross in the the the estimates obtained ticity as ze ro Tncome and shown income At and of the the m e a n price price all at 5% observa­ of price E s t i m a t c s .— and k— are are price foods the for signifi­ coefficients composite estimates are the significance. income for for Except coefficients the values, ^ elasticity negative. E l a s t i c i ty and five more coefficients level Price 17, since procedure. price income in T a b l e for o s t - i m o t e s derived. of from th<-' e s t i m a t e s of th ey a r e estimates different studies, estimation foods, /.2.1. When sectional can elas­ bo food, easily the calculated as follows: where q^ the income the price is the elasticity elasticity average estimate estimate value of = (m/q^) ■- ^Pk^k^ h o u s e h o l d s ’ per , ; capita 11 . quantity is the k— m purchased average on the * k— food, value of price indices for value of h o u s e h o l d s ’ pe r th e food, is the average disposable incom e, and are the estimated cients f or the k— capita and income and price coeffi- ^ U Appendix * ^Th e G. values food, of q. , p. , m, respectively. and m / q k are given in 90 The values lor income the five and price elasticity composite foods are estimates shown at m e a n in T a b l e 18, • i 17 below. TABLE 1H. - - i n c o m e and P r i c e E l a s t i c i t y E s t i m a t e s f o r F i v e C o m p o s i t e F o o d s a f t e r E l i m i n a t i n g the A u t o c o r r e l a te d E f f e c t s Fooas Income Elasticity Price Elasticity .0170 -1 . 4 5 4 3 .0928 -1.5712 Frui ts .1808 -.8158 Vegetables .0 5 3 3 -.7424 Meat, e tc. .14 72 -.3580 Dairy Fats Pioduct.s and Oils ^ T h e s e co mb ined studie s give s u b s t a n t i a l l y lower v a l u e s of i n c o m e e l a s t i c i t i e s t h a n c r o s s s e c t i o n a l s t u d i e s in the p r e v i o u s c h a p t e r . O n e p o s s i b i l i t y to e x p l a i n t h i s p h e n o m e n o n is t h e i m p l i c a t i o n s of F r i e d m a n ' s p e r m a n e n t income hypothe si s. F r i e d m a n h a s d e m o n s t r a t e d t h a t the e l a s ­ t i c i t y of c o n s u m p t i o n w i t h r e s p e c t to m e a s u r e d i n c o m e sep arates into two e l a s tici ti es : the e l a s t i c i t y of c o n ­ s u m p t i o n w i t h r e s p e c t to p e r m a n e n t i n c o m e a n d t h e e l a s t i c i t y of p e r m a n e n t i n c o m e w i t h r e s p e c t to m e a s u r e d i n c o m e . Given the a s s u m p t i o n s of the p e r m a n e n t i n c o m e h y p o t h e s i s , F r i e d m a n d e m o n s t r a t e s t h e e q u i v a l e n c e of the e l a s t i c i t y of p e r m a n e n t i n c o m e w i t h r e s p e c t to m e a s u r e d i n c o m e a n d the e l a s t i c i t y of c o n s u m p t i o n o n m e a s u r e d i n c o m e . Thus, it w o u l d s e e m that the income e l a s t i c i t y e s t i m a t e d from cr os s s e c t i o n al d a t a is a r e a s o n a b l e a p p r o x i m a t i o n of th e e l a s t i c i t y o f the p e r m a n e n t income. As m o r e t i m e s e r i e s d a t a a r e i n t r o d u c e d , the p e r m a n e n t i n c o m e c o m p o n e n t o f the m e a s u r e d i n c o m e is reduced. T h i s r e s u l t s in l o w e r v a l u e s of i n c o m e e l a s t i c i ­ ties d e r i v e d f r o m the c o m b i n e d studies. For more d i s c u s s i o n of this problem, see Friedman, o p . c i t ., S e c ­ t i o n 2, C h a p t e r V I I I , p. 206. 91 From elasticity for The for are highest fruits, the Lansing household fats per per by cent, composite for fats products, and products cent. fruits, .0928, income .0533, elas­ and .1472 products. things disposable on the are all is other a n d meat, income average, in the products; etc. wo u l d .0533, and .1472 estimates for the f i v e .1808, widely etc., -.7424, The p r i c e elasticity an or oils increase fats and for 1 per cent that different. fruit s ; vegetables, or for elasticity other in food w o u l d vegetables; and estimates for for d a i r y meat, etc., d a ir y of price of 1 per cent other the p r i c e meat, being be in t h e things p r o d u c t would be loss b e i n g equal, greater elasticity etc. the p r i c e things -.3580 figures In an that and and The are h i g h l y e l a s t i c . oils, Alternatively, of demand foods p u r c h a s e d on d a i r y and oils ; in d e m a n d increase meat, that, 1 per c e n t , -.8158, fats and sense, a decrease for income .0170 for d a i r y per ca p i t a they a r e - 1. 5 7 1 2 , respectively. 1 per is vegetables; the p r i c e foods, products; dairy .1808, imply capita q u a n t i t y .0170, The the e l as t ic i t y estimate lowest by fruits; composite .0928, figures rises about -1.4543, economic five that respectively. As are area notice E n g e l ’s law. if h o u s e h o l d and oils; increase the income etc.,and the equal, would .0170, Tht’o r c t.ioa 1 ly , these being one They confirm estimates .1808. 18, estimates inelastic. ticity Table of are equal, th a n estimates inelastic. fruits or An vegetables a decrease 1 per than cent. in 92 Jn of income foods, fied and the Engel the d e m a n d probably summary, regardinq the price elasticities r e s u l t s of these curves highly arc theorem. the m a i n The reason siqns for combined this the five studies successful consistency for the of of as estimates composite on they the m o d i ­ confirm the p a n e l success. data is APPENDIX G VALUES OF F oo d s Dairy qk , , m, m / q ^ , A N D Pk Products Py/qy m/qj. P k /(\ 3.74 98 . 39 159 . 40 42.62 26 . 30 1 .03 98.09 159.40 1 5 4 . 75 95.23 Fruits 2.38 97.09 159.40 66 .97 40. 79 Vegetables 2 .09 105.57 159 .40 76 . 26 50 .51 Meat, 6 .82 110.51 159 .40 23. 37 16 . 20 Fats and Oils etc. 93 CHAPTER V SOME PRELIMINARY EVIDENCE EMPIRICAL UTILITY ON APPROXIMATING FUNCTIONS 1. In th i s c h a p t e r , approximating empirical Engel based curves, In a d d i t i o n , study will be 2, some utility areas Utility tiome p r e l i m i n a r y Wald's proposed In t h i s approximating on O b i c c t ivcs theorem, that w e r e for future Functions section, empirical functions some on by m e a n s of will omitted be from g i v e n . ’' t he present research. aad Engel preliminary utility evidence functions Curves evidence on by of means E ng e l F o r a full d i s c u s s i o n o f W a l d ' s t h e o r e m , see A. Wald, op. c i t . , pp. 1 4 4 - 5 5 . T h i s t h e o r e m is a l s o m e n ­ t i o n e d in Z. H e l l w i g , L i n e a r R e g r e s s i o n a n d Its A p p l i c a t i o n t o E c o n o m i c s (New Y o r k : M a c m i l l a n , 1963), pp. 6 2 - 6 3 ; 1’i n t n e r , E c o n o m e t r i c s , op. cit. , pp. 6 0 - 6 1 ; G. T i n t n e r , M e t h o d o l o g y of M a t h e m a t i c a l E c o n o m i c s a n d E c o n o m e t r i c s Tchicago: U n i v e r s i t y Pres s , 1968 ), p p . 21- 23 ; a n d TH T. D a v i s , o p. c i t . , p . 168. M o r e r e s e a r c h in t h i s f i e l d of d e t e r m i n i n g e m p i r i ­ c a l u t i l i t y f u n c t i o n s and c o n d i t i o n s of i n t e g r a b i 1 ity a r e being u n d e r t a k e n at M i c h i g a n St at e U n i v e r s i t y un de r P r o f e s s o r A. Y. C. K o o 's l e a d e r s h i p . F o r s o m e of P r o f e s s o r K o o ' s w o r k s , see A. Y. C. Koo, "An E m p i r i c a l T e s t of R e v e a l e d P r e f e r e n c e T h e o r y , " E c o n o m e t r i c a , 31 ( O c t o b e r , 1 963), pp. 6 4 6 - 6 4 ; A. Y. C. Koo", h R e v e a l e d P r e f e r e n c e : A S t r u c t u r a l A n a l y s i s , " E c o n o m e t r i c a , 39 ( J an u a r y , 1 9 7 1 ) , pp. 8 9 -9 7; a n d A. Y. C~ K o o a n d G. H a s e n k a m p , " S t r u c t u r e of R e v e a l e d P r e f e r e n c e : Some Pr eliminary Evid ence," J o u r n a l of P o l i t i c a l E c o n o m y , V o l . 80 ( J u l y / A u g u s t , 1 9 7 2 ), p p . 724-44. 94 9 l> curves will be p r e s e n t e d . Lhe-wi _ ic-1 utility which the and piaccicul functions. can be determination Also, e n .h 3 i 3 c ;,e to It cross in Chnptoi the most knows the d e m a n d calculate should ITT, of if o n e of the will the note d studies and IV, be to say, impox Lance on i n d e x of the the Engel given M.S.U. provide important the all empirical function for cost great problems is consumers' utility of function l i v i ng . results of the curves as shown price the is of the the u t i l i t y of that it Lo k n o w functions the d e t e r m i n a t i o n sectional Chapter One solved goods. Needless indices as information 2 thirteen in shown needed to 3 approximate the u t i l i t y Before will bo g i v e n presenting P (p the u(q by 1 , ..., p , ..., utility q - (q^, . q n theorem, q n ) be a representative disposable 1 Wald's by W a l d ' s method. some notations first. Denote chased functions n ) be income } be function. an consumer a set the total indicator of n goods at a p e r i o d the c o r r e s p o n d i n g or of set of pur­ t i m e; of p r i c e s ; m be expenditure; a well-defined Given p and m at a period of total time, the ^ F o r m o r e d i s c u s s i o n o f t h e a p p l i c a t i o n s of t h e u t i l i t y f u n c t i o n s , se e Wald, o p . c i t . , p. 1 7 1- 7 5; a n d G. J. S t i g l e r , T h e T h e o r y of P r i c e s T3rd. e d .; N e w Y o r k : M a c m i l l a n , 196 67 ^ p p . T l - 8 3 . 3 F o r a c r i t i c a l e v a l u a t i o n of the p r o b l e m c o n n e c t e d w i t h the e m p i r i c a l d e r i v a t i v e s of i n d i f f e r e n c e s u r f a c e s , se e W. A. W a l l i s a n d M. F r i e d m a n , "The E m p i r i c a l D e r i v a ­ t i o n of I n d i f f e r e n c e F u n c t i o n s , " in S t u d i e s in M a t h e m a t i c a l E c o n o m i c s a n d E c o n o m e t r i c s , e d . b y 0~ Lanqe", e t al. T c h i c a g o : U n i v e r s i t y P r e s s , 1 9 4 2 ) , pp. 1 7 5 - 8 9 . 96 or n e c c s ' v r v firr+ subjected to the budget consumer purchases 3u , 1 — t /p = 33 for m a x i m i z i n g constraint the q u a n t i t i e s is the fulfilled such utility if the as: 3u . n . . . = -^/p 3q h K [■ a ?. condition m k= 1 ^o.lvma p u r c h a s e d as period oi 1 = f functions time w i t h c h a s e d will q 1 , i (m), depend . . . q These loci the the e q u a t i o n s , only on beionys are expansion a certain Assuming function, cally thus, shown of belonging in C h a p t e r For a given quantities th a t pur­ is. curves have represent which To e a c h En g e l curves tim e space ( C). of an d a is c a l l e d s y s t e m of curves. the sam e preference c a n be d e t e r m i n e d e m p i r i ­ by o b ser vi ng to d i f f e r e n t income the c o n s u m p t i o n levels, as III. Considering the , . . . , CT belonging generally, path set Engel in e a c h p e r i o d consumers the income; En g e l al l c o n s u m e r s the income. pri c es , the the q u a n t i t i e s „n , . = f (m) functions consumption more and in the n - d i m e n s i o n a 1 q u a n t i t y prices of of p r i c e s constant n ^no n e t s to consumption ex pansion paths to t h e p e r i o d s the d i f f e r e n t price t j , . . . tT or, situations. If all 97 Fngel C curves (t = 1, points; are lin ea r, . . ., T) each can be d e t e r m i n e d by two of path its say, qt = ' * *' ^t ^ a tor the tn d err'to q. prices consumption expansion p, b - p sake of by t ^t = simplil ication, n and i.L <. , the ^ t f * * *' ^ t ^ * q t, symbols by q of 2t 1 it . is a d v a n t a g e o u s Tor p.,, 9 a n d t■ ’ “► p the set are 2L-1 of also used . Considering point q^ and terminal Wald's T h e o r e m : q n ) which the If there paths an a r b i t r a r y If the p o i n t s of second the linea r space 2, C T , then . . formula the . . initial 2T-1). i n d i c a t o r u (q1 , . . ., degree determined this sa i d the in q by ove r the consumption indicator is consumption expansion proportionality p aro is the factor and constant. considered, F or an arbitrary additive vector coordinates 4 q fc (t = 1, in S by the from an A^, - qgq,. w i t h exists Cj , . . uniquely determined apart v vn , asso ci ated with *-1 1 1 following point dimensional v,, . . expansion paths, vector is a p o l y n o m i a l (2T-1) vectors the proof, c o o r d i n a t e s of a n d A is an a r b i t r a r y the A^, VGCtor i n d i c a t o r as a . . constant, function of the 4 ^2t - 1 : see W a l d , o p . c i t . , pp. 146-53. the 98 ) = I .T-l; 1 . where v p = t-’ 2T-1 t = 1 S=1 5. 2 !3 l k=1 p for t = 0, __ j. k k v = t s t,s > > t s 2T-1 -t ;; o- fc=1 0 t f a k k k. I p.(q - q n > k ^i t s 0 1, . . f’3,2(fjl,3/ p 3, 1* wt = 2T-1; s = 1, . . 2T-1 = “ t ,s w (a + a S ,t the m a r g i n a l s y s t e m of for Q,s t,s 2 is the “ ,V2 , 3 (P1 ,2/ p 2 ,1 J (wi p i,t " D o,t + p o , i )/pt,i ‘if q) = W «- ,s c L '! t Pit prices for 11 = 2 ........ 2T_1 t ' s = 1» 2, 2T-1 ) utility p Practically, of m o n e y (t - 0, one 1, wants at the . point q^ The function to h a v e function ♦-rar.siormation of u(q^, 1 as a 1 V l n q n ) can 4 + 1 1 2 V 2 A • to z e r o , be m a d e • • + n the indicator . . + obtains *2T-1^ as = q n X^ = g of , (q the 2 , q into 0 , q f ° rm 1 - <30 n X 2t — 1 V 2 T - 1 q of follows: 1 T-1V 2T-1 the d e t e r m i n a n t one quantities 1 2 , XfVi + X j ^2 + . II f ( X^ , X 1 of under 2 T - 1). I utility , > ,t , ° ° > 2 n0 . i + P 2 , 3 (o0 , l ~ P 0 f2 ?/° 2 , l “ p 3 t2 (p0 >l P Q , 3 ) / p 3,l 1 n 2T-1 “ q these 1 2 , q n " ^0 equations , ,.., q is n, ^ ) for no t equal 99 t ~ 1, 2, 2T-1. i‘{-'■j f •••/ cator of X 2 ^_ ^ ) , one o b tains the u t i l i t y To functions by means and of for method Engel the the se X u f q 1 , . .., f u n c t i o n as a present Wald's su c h m e t h o d o l o g y space Substituting q r')f of a p p r o x i m a t i n g Figure two p e r i o d s of time. 6 indi­ . ••, q n . utility roughly three-dimensional two c o n s u m p t i o n e x p a n s i o n p a t h s bci.orujj.ng to the f u n c t i o n of q \ curves, c a s e of into shows commodity and 5 c“ Figure 6 .- -A D i a g r a m S h o w i n g W a l d ' s M e t h o d , w i t h T h r e e D i me n si on al C o m m o d i t y Space and T w o C o n s u m p t i o n Expansion Paths For a numerical c o m m o d i t i e s , no. 1 illustration, = dairy products, consider no. 2 the = fats three a n d oils, C F o r n u m e r i c a l i l l u s t r a t i o n s of W a l d ' s m e t h o d of a p p r o x i m a t in g utility functions by means of Engel curves, see Wald, o p . c i t . , pp. 1 5 3 -5 5; a n d T i n t n e r , E c o n o m e t r i c s , o p . c i t . , pp. 60-61. 100 no. t2 3 = fruits, - period 2 and t wo p e r i o d s pj = P J2 - 97<>, 1 where . pj = p^ period P2 1 , p3 = “ *970, is the the time, t^ = p e r i o d 1 , as these thr ee commodities in follows:^ ; p price 1, 3 - 1.132; i n d e x of the good at the t— .0009 in2 1. 4 5 9 + .0029 m x is g i v e n by at period the consumption expansion set uf En g e l path is curves:^ = 3.798 + .0005 m 2 q2 =■ 1.0 5 1 + .0007 m 2 q = .0018 m 2 1.649 + 1 . 2, following q3 ^For that p e r i o d the .0011 m-^ + And 3 1 following 3.67 a + q 3 =_ .yoi q3 = of oJ. time. g i v e n by - i n d i c e s of are g i v e n At p er i o d q^ two p e r i o d s . The p r i c e the the the c o n s u m p t i o n set of Engel expansion path C 2 curves: ; the p r i c e i n d i ce s , see T a b l e is the b a s e d p e r i o d . 15, p. 80. Assume 2Fo r the E n g e l c u r v e s , see T a b l e 1 t h r o u g h T a b l e 5, pp. 37-41. In o r d e r to o b t a i n the q u a n t i t i e s p u r c h a s e d q as a f u n c t i o n of m, the e s t i m a t e s of the r e g r e s s i o n c o e f f i ­ c i e n t s a re d e f l a t e d by the p r o p e r p r i c e i n d ic es . 101 V q v is where the good, m^ is per capita quantity capita disposable On the per two p o i n t s C ] , the income points £15 0 sponding to »5o E' P 1 =' p 2 -- p 3 li o ^1 " q2 - the on e a c h qg C ft = the disposable on the income th k— the at period function by Wald's ,2 ) h a v e to be to points £160 and the chosen. disposable and £1 7 0 t. q-^ c o r r e ­ are chosen. p 's: obtains tli- 1, 1) (.979, .970, 1 . 1 32 ) (3.8430, 1 .0360, 1 .8940) (3.8540, 1.0450, 1 .9230} f7 .8 7 9 7 , 1.1665, 1 .9448) (3.8849, 1.1738, 1 . 96 33) The 1 income corresponding S]6 Q , and one utility and and Hence, of and To approximate method, purchased followinq figures are the values of t ,s t 0 1 2 3 s 1 2 3 .0490 .0490 .0524 . 0524 .2181 .2 1 8 1 .2 2 0 2 .2 2 0 2 .24 9 0 .2490 .2 5 3 2 .2 5 3 2 T h e s e l e v e l s o f i n c o m e a r e a r o u n d the m e a n observ ed per c a p i t a d i s p o s a b l e income; see A p p e n d i x p p . 7 3-75. of F, the 102 As money at for the the p o i n t values of w^, q t under the the m a r g i n a l s y s t e m of u t i l i t y of prices p t , one obtains : w^ - 1.0065 w 2 - .9215 w 3 = .9193 Tiic l o i i o w i n y t s 3 One would Thus, fun''Mr n as of a t , s ’s: 3 notice -.0008 -.015? -.0157 that the v a l u e s Hence, of a . 5 (- . 000 2 t A^ = a f 5 <7 t,s o ne can o b t a i n a f u n c t i o n of f ( X l ,?'2'? 3 ) = = — (n ) - n indicator 1^ » *3 as A^ - .0162 .0008 A ^ - .0009 A 3 A3 - .0157 A 3 X 2 )+ + .2181 A2 + .2490 A3 s,t of the = t,s utility foll ow s: A1 A^ - transformation + a t,s .0009 the t,s the A ^ - .0152 to o b t a i n . for all S ^ i 2 - A 3 - .0157 .0490 .0008 AjA2 A2 A 3 Aj + A indicator as a f u n c t i o n of q u a n t i t i e s following -.0009 -.0157 - .0162 - In o r d e r the the v a l u e s -.0002 -.0008 -.0009 1 function are 1 2 1,2,3. figures is made: of the u t i l i t y purchased q 1 7 , q*, q 3 , 103 .0110 + .0367 A + .0419 >, = q 1 - 3 . 843 0 + . 1 378 * - 1 . 0360 .0 O 9 L » ■x ^ .1305 A2 .0290 \1 + X2 .0508 Since equa l + . 06 9 3 the v a l u e s - q2 A 3 - q 3 - 1.8940 th e d e t e r m i n a n t to zero, 3 of of those equations X 2 , anc^ ^3 are is not calculated as : A = 287.2330 q1 - 58.9996 q 2 - 56.1575 X2 - 471.4688 q - 63.0785 q 2 - 159.2569 q A3 - -465.5462 1 q1 + 70.8890 q 2 Substituting gets of the in i n d i c a t o r of f(A^, the q 3 3 - 661.292 - 212.207 + 154.5865 q 3 + 454.696 A 2 ' * 3 ) f ° r *]» utility *2' *3' one f u n c t i o n as a f u n c t i o n q 1, q 2, q 3. Wi t h an can be an d periods As no. = fruits, three period computer, a p p r o x i m a t e d by e x t e n d i n g T-periods ties, electronic of of the utility number to n - d i m e n s i o n a l functions of c o m m o d i t i e s commodity space and time. for a n o t h e r 1 = dairy numerical illustration, p r o d u c t s , no. no. 4 = v e g e t a b l e s , no. periods 3, time the of time, tj_ = p e r i o d are considered. 2 five = fats a n d o i l s , 5 = meat, 1 ,t 2 = commodi­ no. 3 etc., a n d period 2 , t3 = 104 T he three Pi price periods lf Pi = p4 2 = 1.013, 4 q1 + = by + q4 = the 1, .0018 m 3 q + . 0 0 0 5 m 2 ,q + 1.954 .0025 , q4 = = .993, k commodities 1 follows: *9 7 9 ' where = p2 is = p^ = -9 7 0 ' P 2 .946 , 1 in the 2 , p^ = 1.07 6 , index of the s e t of E n g e l = 2 + .901 by m 3# 1.67 4 = 1.051 + ,q by the set q2 + .0007 + + is + 5 1.649 .0 1 2 2 m 2 . Engel .0007 m 3 , q 3 .0017 m 3 , q = 6.087 ni! . curves: m2, q3 s e t of 1.459 + .0 1 1 2 Engel = 5.855 5 following = .955 of = 3 = 5.993 5 .0012 m 2 , q the path curves: + . 0 0 0 9 rr^ , q . 0024 2 expansion curves: = + 1.667 . 00 7 6 m 1 . i_ where q good, and period is the per capita quantity is per capita d i s p o s a b l e the purchased o n t he income k— at t. On disposable , the p o i n t s income 1 = 3 *1 3 2 ' p3 = the price consumption 2 is g i v e n is q i v e n = 3.389 five given as P2 = the 1 . 779 = these t. .0 0 1 1 .0018 m 2 , q 4 And q1 3.798 I? 1.013; st p e r i o d - are following + .0029 m 1# q1 = of 1.022; p* period the 3.678 The + 5 = = at p e r i o d At given time Pi p| - 1.1]3, k — . q oo d of indices $150 a n d q^ and q ^ $160; on corresponding C 2 * the p o i n t s to q2 the and ; , 105 q^ corresponding and on the disposable points income Hence, po = P1 = P2 ~ J3 o 1! P4 - *1 = to the d i s p o s a b l e one $160 a n d q,- c o r r e s p o n d i n g $170 and $180, are and to the chosen. 1, 1, 1) 1, ;3 - (. 979 , .970 , 1 .J 3?, 3.013, 3 .022 ) Pj. - ( .99 3 , .946 , 1 . 076 , 1 .1 1 3 , 1.013) (3.8430, 1.0360, 1.8940, 2.1390, 7.6730) (3.8540, 1.0450, 1 .923 0 , 2. 1 6 3 0 , 7 .7850) q2 ~ (3.8797, 1.1665, 1 .9448 , 2.1582, 7.8056) q3 = (3.8849, 1.1738, 1.9633, 2.1710, 7.9278) (3.8175, 1 .0806, 1.9832, 1 . 9634 , 7.3776) (3.8427, 1 .0880 , 2 . 0 01 8, 1 . 9804 , 7.4536) q4 " q5 = The t following s $170; obtains 1, C income figures are the v a l u e s of „ 1s : 1 2 3 2 .18 50 . 185 0 .1 9 1 2 . 3699 . 3699 . 3753 .5 358 . 5358 .5463 -.3627 -.3627 -.3608 -.2185 - . 2185 -.2129 3 4 5 . 19 1 2 .1909 . 190 9 . 3753 . 3705 . 3705 .5463 . 5405 .5405 -.3608 -.3820 -. 3820 -.2129 -.2340 -.2340 0 1 As for money at o b ta i ns : th e v a l u e s the p o i n t of w^, under the 4 p. the m a r g i n a l 5 utility system of prices of p t , one 106 1.0911 w] = 1 . 143b II S CJ W 2 1.2225 .7962 W4 = .8650 w5 = ihese u t i l i t y of income s values 2 3 4 5 The s 1 2 3 4 5 is the pe r t ,s ps a r e as lh.it the m a r g i n a l capita disposable .0168 .0 337 . 048 8 -.0330 -.0199 one . 0337 . 05 9 3 .0889 -.0749 -.0495 4 are the v a l u e s of A^, the A0 , u t ,s 1s ; 5 - .0330 -.0624 -.0919 .0585 .0322 .0488 .0889 .1321 -.0919 -.0550 can obtain -.0199 -.0250 -.0418 .0321 .0160 4 3 . 0337 . 05 93 . 0889 -.0624 -.0372 5 - .033 0 -.0499 - . 07 8 4 .0585 .0322 .0488 ,0889 .1321 -.1055 -.0683 figures a function of follows: 3 2 1 as a 2 following T hu s , function of 1 .0168 .0337 .0488 -.0330 - .0199 1 t m o n e y dec:linos t.e i n d i c a t e increases. The t l j 4 , A^ as utility follows: 107 f (> 1 , ' *o , > , , > , i r ) = . 5 ( .01 6 R A^ + .0 5 9 3 i 2 + . 1 3 21 > 2 J + .0 5 8 5 A ^ In o r d f r func’ t-i on 4 t] , and .0110 A as + .0160 + .0337 + .0488 A.X_ + .0337 a ~ .0372 A2A5 + ? ■>A 4 “ .0550 Ay 0624 A^A-, - .0199 A.A. 5 1 + .0322 A 5 A 4 ) + .1850 + .5358 A3 to o b t a i n a function - >2 1 3 the .0330 > + - A, A 14 .0889 a .04b8A3A1 A1 A2 - .0199 A A A - .0624 a A4 + .0869 A 3A2 “ .0530 X4 A 3 .0919 A4 A 3 + . 0 3 22 A4 A5 .0372 A-A, 5 2 .0550 Ac A 5 3 .3627 > 4 indicator of q u a n t i t i e s 5 Ax + - of .3699 .2185 A2 A 3 A the u t i l i t y purchased q 1 2 , q , q 3 , r q , the + .0367 following A2 + transformation .0419 A3 - .0255 is made: - .0003 q1 .0090 1 5 X1 + .1305 A2 +• .1375 A3 + .0446 A4 + .0520 A5 - A5 = 3.8 4 30 - q 2 - 1.0360 108 0290 X + .0508 X2 + .06 93 > 3 + .0892 + .1078 q 0 24 0 X. + 1 .0192 ^ A, + .0 3 2 0 3 X, - .1756 4 L - 5 X5 = - 1.89 4 0 3 .1586 X, „ 4 _ 2.1390 112 0 + .1326 X? + .2548 X3 - .2954 X - .2194 X5 q Sinco equal to zero, lated as : XL -36.7916 A2 > = ^ = = the d e t e r m i n a n t the v a l u e s q q5 -.9020 q 1 + 8 .2 2 6 8 - 1 7 . 72 8 4 q5 + + 17.5 04 5 q5 -57.0921 q 1 = 57.5593 q 1 + 1 . 5990 q 5 these equations \ 2 , X 3 , X 4 , A5 q2 + 52.9775 q 3 - 7.6730 5 is not are calcu­ + 49.8635 q4 - 27.9322 q2 + 27.9770 q3 + 46.2554 q 4 + 20.9552 .7735 q 2 - 1 . 74 4 5 q 5 X5 - 6.0435 1 - 1 1 . 37 4 8 .0177 q 1 of of = - 30.7245 q 3 - 44.8605 q 4 - 18.9673 + 10.666 q2 + 12.8541 q 3 + 14.7763 q4 - 165.7879 - 11.5761 q2 + 164.6116 - 9.0355 q 3 - 18.5843 q4 109 Substituting ' -j, ) q , > c , one gets as a f u n c t i o n of q utility function The least, that functions theorem cal in f{ , q 3 , q 4 , q 5 the u t i l i t y . Of complicated course, than A^, th is the p r e v i o u s approximate determination of of Engel Mo r e curves could research on is n e e d e d i n t e g r a b i l i t y , and of e q u i l i b r i u m ar e needed for to bo the the at if W a l d ' s f i e l d of e m p i r i ­ undertaken. sufficient further one. utility be m a d e , this A2 , function indicate, functions of , q A j. ) for illustrations is a d o p t e d . conditons i n d i c a t o r of A^, numerical by means utility 2 is m o r e above the 1 the A ^ , A 2 , A^, The condition empirical test before 9 any economic policy 3. Besides be p r o p o s e d area, to recommendation Areas some in t h i s areas Box-Cox model Future mentioned section in p a r t i c u l a r , supplement for c a n bo d r a w n . for c o u l d be It is to linearity of an area will research.^ undertaken study. the earlier, future the p r e s e n t test Research an d the Engel This le a d d i r e c t l y us e of the curves. Th e f u l f i l l m e n t o f the s u f f i c i e n t c o n d i t i o n of e q u i l i b r i u m i m p l i e s that the e q u i l i b r i u m p o s i t i o n is the m a x i m u m one. T h e f u l f i l l m e n t of the i n t e g r a b i 1 ity c o n d i ­ t i o n s m e a n s t h a t t h e r e e x i s t s one a n d o n l y o n e i n d i c a t o r of u t i l i t y s u c h that a l o n g the g i v e n c o n s u m p t i o n e x p a n s i o n p a t h s the n e c e s s a r y c o n d i t i o n s for the e q u i l i b r i u m p o s i t i o n ar e f u l f i l l e d . F o r the e m p i r i c a l t e s t s of t h e s e areas, see Wald, op. cit. ^ O t h e r p o s s i b l e a r e a s of r e s e a r c h a r e the s i m u l t a n e ­ o u s e q u a t i o n s , t h e d y n a m i c m o d e l s , the p r o j e c t i o n s of h o u s e h o l d s ' e x p e n d i t u r e b e h a v i o r , the e s t i m a t i o n of c o e f f i ­ c i e n t s of e c o n o m i e s of s c a l e , etc. For more specif ic areas of r e s e a r c h , see Q u a c k e n b u s h a n d S h a f f e r , o p . cit. , pp. 46- 5 1. 110 Consider y i the following function: ) ~ m . - 1 — = r,k where is m. > Bk 4 the the is 1 u ik 4 household k^- food at per c a p i t a a period th i— household the of pe r expenditure on time , capita disposable i income at t>.y , tiy , a no U., ik is tor lyik - C where which k / - 4 "k - ■ it* --k is a y ik which 6 * >. ar e 1 , one 4 . k P - ..k k error and term, 4 1( u i 4 “ ik k 1 regression model. one obtains log is a d o u b l e - l o g functional " linear In g e n e r a l , ferent i B, •+ k A - 0, + ek m time, obtains + V " ! ; of parameters, stochastic simple For loq the a period mi + u ik regression model . different values specification of of the A lead to regression dif­ equation Ill This allows alternative v > - 1 l!a : > * and its along one to test the h y p o t h e s i s .^^ linear hypothesis against the Formally, 1 To carry out standard error. with the the other test, one Obviously, parameters by needs an e s t i m a t e > ran the be of 1 estimated maximum likelihood me thorl. The likelihood function for y ^ j , . . yn^ is y X _x 0.-1):: log y ik - | log 211 - £ l o g o 2 2o n,X-l - - The found with standard V - r r appropriate 2 • 11 maximizing values an e l e c t r o n i c errors T. I (“ ^ -- ) i can of A, computer, be e s t i m a t e d by ^ , and and the o** c a n be respective reference to t h e information matrix. F o r m o r e d i s c u s s i o n of thi s p r o b l e m , s e e G. E. P. B o x a n d D. R. C o x , "An A n a l y s i s of T r a n s f o r m a t i o n s , " J o u r n a l o f the R o y a l S t a t i s t i c a l S o c i e , S e r i e s B, V o l . 26 (11)64) , p p . 2 1 1 - 4 3; a l s o , K m e n t a , o p . c i t . , pp. 46 7- 6 8 . It s h o u l d b e n o t e d that the m a i n t a i n e d h y p o t h e s i s c o u l d b e the d o u b l e - l o g f o r m , or Hq : A = 0 a g a i n s t H 2 : A ^ 0. BI BL IO G R A P H Y 112 BIBLIOGRAPHY 7\itchison, J., tion . Allen, Ames, a n d Brown, Cambridge: R. G. D., Lonaon: J. A, C. The L o g n o r m a l D i s t r i b u ­ U n i v e r s i t y Press, 1957. a n d B o w l e y , A. S t a p l e s , 19 35. L. Family Expenditure. L . , and Re i t e r , S. " D i s t r i b u t i o n s of C o r r e l a t i o n C o e f f i c i e n t s in E c o n o m i c T i m e S e r i e s . " Journal t he A m e r i c a n S t a t i s t i c a l A s s o c i a t i o n , V o l -^ 53 T S e p t e m b e r , 191!> 1) . Bell, C. S. C o n s u m e r C h o i c e in the York: R a n d o m H o u s e , 1967. American Economy. of New Brady, D. S., an d F r i e d m a n , R. " S a v i n g s and the I n c o m e Distribution." N . B . E . R . S t u d i e s in I n c o m e and W e a l t h . Vol . 10. N e w York, 1947. Brown, J. A. C. " S e a s o n a l i t y and the E l a s t i c i t y o f D e m a n d for Food in G r e a t B r i t a i n S i n c e D e t e r a t i o n i n g ." J o u r n a l of A g r i c u l t u r a l E c o n o m i c s , Vol. 13 (June, l y T s T : -------- ----- Box, G. Burk, ------------------- E. P., and Cox, D. R. "An A n a l y s i s of T r a n s f o r m a ­ tions." J o u r n a l of the R o y a l S t a t i s t i c a l S o c i e t y , S e r i e s B, Vol. 26 (1964) , p p . ^67 M. C. " I n c o m e F o o d R e l a t i o n s h i p s fr o m C r o s s S e c t i o n a n d Time S e r i e s S u r v e y s . " P r o c e e d i n g s of the A m e r i c a n S t a t i s t i c a l A s s o c i a t i o n . B u s i n e s s and E c o n o m i c S t a t i s t i c S e c t ion , 1"9™5 7 . ___________ . I n f l u e n c e of E c o n o m i c a n d S o c i a l F a c t o r s on U.S. F o o d C o n s u m p t i o n . Minn.: Burgess P u b l i s h i n g , c----t t s t :-----Christ, Clark, C. F. Econometric Models J o h n W i l e y Z S o n s , 1966. and M e t h o d s . N e w York: F., et al. "Food C o n s u m p t i o n o f U r b a n F a m i l i e s in t h e U n i t e d Sta te s . Agricultural Information Bulle­ t i n No. 1 3 2 . W a s h i n g t o n , D . C . : U.S. D e p a r t m e n t o f A g r i c u l t u r e , 1954. 113 114 C o c h r a n e , D . , a n d O r c u t t , G. . res Fr.gr - i-sions Autocorrelated Error American Statistical 1 949 ) , pp. 32-61. Cramer, H. " Ap pl ic a t i o n of Least 1 c Pelati o r s h ips Containinq Terms." J o u r n a l o f the A s s o c i a t i o n , V o l . 44 TMarch, J. S. Empirical E c o n o m e t r i c s . Ho H a n d P u b l i s h i n g , 196 9 . Amsterdam: North- "Efficient Grouping, Regression, and C o r r e l a ­ t i o n in E n g e l C u r v e A n a l y s i s . " J o u r n a l o f the A m e r i c a n S t a t i s t i c a l A s s o c i a t i o n ^ T9 (1964) . C r o c k e t t , J. "A N e w T y p e of E s t i m a t e of the I n c o m e E l a s ­ t i c i t y o f the D e m a n d for F o o d . " P r o c e e d i n g s of t h e Am e r i c a n S t a t i s t i c a l A s s o c a t i o n . B u s i n e s s a n d E c o n o m i c S e c t i o n ^ IT9 b 7 . ___________ . " De m a n d R e l a t i o n s h i p s for F o o d . " of the C o n f e r e n c e o n C o n s u m p t i o n and P h i l a d e l p h i a j i960. Proceedings Saving, V o l . I. C r o c k e t t , J . f a n d F r i e n d , I. "A C o m p l e t e S e t o f C o n s u m e r Demand Relationships." P r o c e e d i n g s of the C o n ­ f e r e n c e o n C o n s u m p t i o n a n d S a v i n g , Vol. 1. P h i l a d e l p h i a , 1960. Davitl, M. H. dam: Family Composition and C o n s u m p t i o n . N o r t h - H o l l a n d PTiblishing, 1962. D a v i s, H. T. Th e T h e o r y o f E c o n o m e t r i c s . Ind. : Principle P r e s s , T9 41. Amster­ Bloomington, D u e s e n b u r r y , J. Income, S a v i n g a n d the T h e o r y o f C o n s u m e r Behavior . Cambridge : Harva rd U n i v e r s i t y Press, i9^r. — Dunsing, M . , a n d Re i d , M. G. " E f f e c t o f V a r y i n g D e g r e e of T r a n s i t o r y Income on Income E l a s t i c i t y of E x p e n d i ­ tures." J o u r n a l of A m e r i c a n S t a t i s t i c a l A s s o c i a t i o n , Vol. 53 (June , 1958) , p p . 3 5 7-5'9 . Ezekiel, M . , a n d Fox, K. A. M e t h o d s of C o r r e l a t i o n a n d Regression A n a l y s i s . 3rd ed. N e w York: John Wi ley Z S o n s , 19 5'9 . Ferber, R. " R e s e a r c h on H o u s e h o l d E c o n o m i c T h e o r y . V o l . III. Press, l9d6. Ferber, R . , a n d V e r d o o r n , P. o m i c s an d B u s i n e s s . J. New Behavior." Surveys New York: St. of Martin"s R e s e a r c h M e t h o d s in E c o n ­ Y o r k : M a c m i 1 l a n , 19 6 2. 115 Fox, K. 7\. Intermediate Wi l ey ** Economic Son a, S t a t is t i c s . N e w York: ]y68. F r i e d m a n , il. A T h e o r y of the C o n s u m p t i o n F u n c t i o n . Princeton: N a t i o n a l B u r e a u of E c o n o m i c R e s e a r c h , 1957 . G o l d b e r g e r , A. S. Econometric W i l e y & Sonifi 1964. Theory. New York: John G o l d s t e i n , S. S t u d y on C o n s u m e r E x p e n d i t u r e , Inco me s , S a v i n g s : C o n s u m p t i o n P a t t e r n s ol the Aged"! U n i v e r s i t y of P e n n s y l v a n i a , 1960. Goreux, and L. " L o n g R a n g e P r o j e c t i o n s o f Food C o n s u m p t i o n . " F A O M o n t h l y B u l l e t i n of A g r i c u l t u r e , E c o n o m i c s and S t a t i s t i c s . Vof. (T (June, 1957). G r i s h i c k , M . , a n d H a a v e l m o , T. " S t a t i s t i c a l A n a l y s i s of th e D e m a n d for F o o d: E x a m p l e s of S i m u l t a n e o u s E q u a ­ tions." E c o n o m e t r i c a , Vol. 15 (August, 1947). He 11w i g , Z. L inear Economics . R e g r e s s i o n and Its A p p l i c a t i o n New York: M a c m i 11a n , 19 b~3~. H e n d e r s o n , J. M . , a n d Q u a n d t , R. E. Micro-economic 2nd ed. N o w York: M c G r a w - H i l l , 1971. to Theory. H e r r m a n n , R. O. "Household So ci o-e co no mi c and Demo gra ph ic C h a r a c t e r i s t i c s as D o t e r m i n a n t s of F o o f E x p e n d i t u r e Behavior." U n p u b l i s h e d Ph.D. d i s s e r t a t i o n , D e p a r t ­ m e n t of A g r i c u l t u r a l E c o n o m i c s , M i c h i g a n S t a t e U n i v e r s i t y , 1964. Hicks , J. R. Value? and C a p i t a l . C l a r e n d o n Press, 1946. 2nd ed. Oxford: H o u t h a k k e r , H. S. "The E c o n o m e t r i c s of F a m i l y B u d g e t s . " J o u r n a l of the R o y a l S t a t i s t i c a l S o c i e t y , S e r i e s A, Part 1 (195 2). ___________ . "An I n t e r n a t i o n a 1 C o m p a r i s o n of E x p e n d i t u r e P a t t e r n s , C o m m e m o r a t i n g the C e n t e n a r y of E n g e l ' s Law." E c o n o m e t n c a , Vol. 25 (October, 1957), pp. 5 30-3TT Houthakker, th e e3"! H. S., a n d T a y l o r , L. D. C o n s u m e r D e m a n d in Unite d States: A n a l y s e s and P r o j e c t i o n s . 2nd H a r v a r d : U n i v e r s i t y P r e s s , 3T9 70 . J o h n s t o n , J. 1963. Econometric Methods. N e w York: McGraw-Hill, 116 J o r g e n s o n , E. Income Expenditure Relations of Danish Wage and Sn ia r y i'lnrnor.s . C o p e n h a g e n : K o b o h a v e n , 1 965. K at z n o r , I). V/. 1970 . Kane, J. Economic Statistics H a r p e r 6. R o w , 1968. E. Klein, Static Demand L. R. A Textbook P e t e r s o n , 1953. _ of Theory. N e w Yor k : & Econometrics. Econometrics. • I n t r o d u c t i o n to E c o n o m e t r i cs. Cliffs: P r e n t i c e Ha"ll , 1962. K m e n i n , J, E l e m e n t s of 1971. K o o , A. Econometrics. A. Evanston: Row, Kngelowood N o w York: Macmillan, A Structural Analysis." 1971), pp. 89-97. Y. C., a n d H a s e n k a m p , G. " S t r u c t u r a l of R e v e a l e d Preference: Some P r e l i m i n a r y E v i d e n c e . " Journal of P o l i t i c a l E c o n o m y , Vol. 80 ( J u l y / A u g u s t , 19721, pp. 724- 4 4. Kuh, E . Leser, N e w York: Y. C. "An E m p i r i c a l T e s t of R e v e a l e d P r e f e r e n c e Theory." E c o n o m e t r i c a , 31 (October, 1963), p p . 64 6-64. ________ . "Revealed Preference: E c o n o m e t r i c a , 39 (January, Koo, Macmillan, C a pital Stock Growth: Approach I A m s t e r d a m : 1963. C. E. omic A Micro-econometric North-Holland P u bl ishing, V. " D e m a n d R e l a t i o n s h i p s for I r e l a n d . " E c o n ­ R e s e a r c h I n s t i t u e P a p e r , No. 4. Dubl i n , 1 9 6 2 . ___________ . " F o r m s of Eng e l F u n c t i o n s . " TOctober, 1963), p. 694. Econometrica, 31 " F a m i l y H u d g e t D a t a an d P r i c e E l a s t i c i t i e s of Demand." R e v i e w of E c o n o m i c S t u d i e s , Vol. 9, 1941. L i v i a t a n , N. Fa 1, Consumption Patterns " E r r o r s in V a r i a b l e s E c o n o m e t r i c a , 29 (1961), Mack, R. in a nd pp. Israel. Jerusalem: Engel C u r v e 336-62. Analysis." P. " E c o n o m i c s of C o n s u m p t i o n . " A S u r v e y of C o n ­ t e m p o r a r y E c o n o m i c s . Vol. II. E d i t e d b y D . F~. Haley. Illinois: R i c h a r d D. Irwin, 1952. 117 M a l i n v a u d , E. S t a t i s t i c a l Me t h o d s of E c o n o m e t r i c s . 2nd e d . N o w York : A n c r ica n El sc v i c e Pub! i shi nq r 19 7 0 . M a r s c h a k , J. " H c v i e w o f S c h u l t z , T h e o r y and M e a s u r e m e n t of D e m a n d ." E c o n o m i c J o u r n a l ! Vol . 3"3 (19 39) , p! 4 6 7. M o d i q l i a n i , F. " F l u c t u a t i o n s in t h e S a v i n g A P r o b l e m in E c o n o m i c F o r e c a s t i n g . " S t u d i e s in I n c o m e an d W e a l t h . Vol. 1949. Income Ratio: N.B.E.R. 11. N ew York, M o d i g l i a n i , F., and A n d o , A. "The P e r m a n e n t I n c o m e a n d the Life Cycle H y p o t h e s e s of S a v i n g b eh avior, C o m p a r i s o n a n d Tes t ." P r o c e e d i n g s o f the C o n f e r e n c e on C o n s u mpti. cm a n d ' S a v i n g . VoT! 1 1 . E d i t e d b y F"! F r i o n d a n d R. J o n e s . P h i l a d e l p h i a , 1960. Morgan, The J. N. "A R e v i e w of R e c e n t R e s e a r c h on C o n s u m e r Behavior." C o n s u m e r Be h a v i o r : R e searc h on C o n s u m e r R e act i o n s . E d i t e d by- L. H. C l a r k ! New York : H a r p e r , 1958. N a t i o n a l Food S u r v e y C o m m i t t e e . Domestic Food C o n s u m p ­ t i o n and E x p e n d i t u r e . London! H . M . S . O ., 19 6 51 Nerlove, M. "The I m p l i c a t i o n s of F r i e d m a n ’s P e r m a n e n t I n c o m e H y p o t h e s i s for D e m a n d A n a l y s i s . Agricultural E c o n o m i c R e s e a r c h , J a n u a r y 1958. P a t i n k i n , D. York: M o n ey , I n t e r e s t , a n d H a r p e r & R o w , 1 9 6 5! Prices. “ ’ 2nd ed. New Prais, S. J. " N o n - l i n e a r E s t i m a t e s of the E n g e l C u r v e . " R e v i e w of E c o n o m i c S t u d i e s . Vol. 20, 1 9 5 2 - 5 3 . Prais, S. J., and H o u t h a k k e r , Budgets. Cambridge: Price, D. W. " A g e - S e x E q u i v a l e n t S c a l e s for U n i t e d S t a t e s Food Expenditures--Th_-ir C o m p u t a t i o n and A p p l i c a ­ tion." U n p u b l i s h e d Ph.D. d i s s e r t a t i o n , D e p a r t m e n t of A g r i c u l t u r a l E c o n om i cs , M i c h i g a n S t a t e U n i v e r s i t y , 1 965 . H. S. T h e A n a l y s i s of F a m i l y U n i v e r s i t y ^ P r e s s , 1971 . Q u a c k e n b u s h , G. G . , a n d S h a f f e r , J. D. "Collecting Food Purchase Data by Consumer P a n e l : A M e t h o d o l o g i c a l R e p o r t on t h e M . S . U . C o n s u m e r P a ne l , 1 9 5 1 - 5 8 . " Technical B u l l e t i n 1 7 9 . M.S.U. A g ri c ultural E x p e r i m e n t S t a t i o n , A u g u s t 1960. S a m u e l s o n , P. A. R e v i e w of " S o m e I m p l i c a t i o n s of ' L i n e a r i t y . ' " E c o n o m i c S t u d i e s , 1947-48. The llu S c h u l t z , H. Th e o r y and M e a s u r e m e n t ’’d i v e r s i t y Pres s, 19 37. of Demand. Chicago: Hchump>o ter, .7. A. H i s t o r y of E c o n o m i c A n a l y s i s . O x f o r d U n i v e r s i t y P r e s s , 1/95 4 . New York: S l a t e r , J. M. "Regional C o n s u m e r Ex penditure S t u d i e s Using Na ti on al Food S u r v e y Data." J o u r n a l of / A g r i c u l t u r a l E c o n o m i c s , (May, 1 9 6 9 ) , p. 1971 S n y d e r , E. M. "Long-term Ch an ges and Fam i l y E x p e n d i t u r e s . " Consumer Behavior: Research on Co nsumer R e a c t i o n s . E d i t e d b y L. H. C l a r k , New York: H a r p e r & Bros., 1 9 5 fl . S p 11; k .>, W. R. " E s t i m a t e s of the D e m a n d for F o o d F r o m C o n ­ sumer Panel Data." U n p u b l i s h e d P n .D . d i s s e r t a t i o n . D e p a r t m e n t of A g r i c u l t u r a l E c o n o m i c s , M i c h i g a n S t a t e U n i v e r s i t y , 1961. S t i g l e r , G. J. The Theory M a c m i 11 a n , 1966 . of Price. . "The E a r l y H i s t o r y of sumer Behavior." Journal Vol. 42 (April, 1 9 5 4 ) , pm 3rd e d , New York: E m p i r i c a l S t u d i e s of C o n ­ of P o l i t i c a l E c o n o m y , 98. Stont? , <. , e t a 1. T h e M e a s u r e m e n t of C o n s u m e r E x p e n d i t u r e a nd B e h a v i o r in t h e U n i t e d K i n g d o m , 1 9 2 0 - 3 8 . C a m b r l d q c : U n i v e r s i ty P r e s s , 19 5 4. S t u v a l , C., a n d J a m e s , S. F. " H o u s e h o l d E x p e n d i t u r e s on l o u d in H o l l a n d . " J o u r n a l of R o y a l S t a t i s t i c a l S o c i e t y , S e r i e s A, 1 1 1 (19 5 0), p. 59. S u m m e r s , R. "A M o t e o n L e a s t S q u a r e B i a s in H o u s e h o l d Expenditure Analysis." E c o n o m e t r i c a , 27 ( J an ua r y, 1959 ) , p. 121. T i n t n e r , C. Econometrics. 1952. New York: John Wiley & Sons, _. M e t h o d o l o g y of M a t h e m a t i c a l E c on om ic s and metrics . Ch i c a g o : U n i v e r s i ty Pr o s s , 1968. Tr ntnei Tobin, G . , a n d S e n g u p t a , J. K. Stochastic N e w York: A c a d e m i c P r e s s , 19 72. Econo­ Economics. f. "A S t a t i s t i c a l D e m a n d F u n c t i o n for F o o d in the U.S.A." J o u rn al o f the Royal S t a t i s t i c a l Society, S e r i e s A '(19SIT',' p. IT'S. --------------------------- 119 The. II. S . B u r e a u of L a b o r S t a t i s t i c s for the W h a r t o n S c h o o l ■if F i n a n c e , U n i v e r s i t y of P e n n s y l v a n i a . S t u d y of C o n s u m o r E x p e n d i t u r e s , I n c o m e s and S a v i n g s . V o l . I-Il. U n i v e r s i t y of P e n n s y l v a n i a P r e s s , 1956. Wa i te , W. c. , and Ire lagan, H. C. Agricultural Prices. 2nd e d . N e w Yor k: John~wiley I"951. Market & Sons, WaId, A Wa J 1 1 , W. A . , and F r i e d m a n , M. "The E m p i r i c a l D e r i v a t i o n of I n d i f f e r e n c e F u n c t i o n s . " S t u d i e s in M a t h e m a t i c a l E c o n o m i c s and E c o n o m e t r i c s . E d i t e d b y O . Lange, e t al. Chicago: U n i v e r s i t y P r e s s , 1942. Wang, H . F. "B e t a i l F o o d P r i c e I n d e x B a s e d on M . S . U . C o n ­ sumer Panel." U n p u b l i s h e d Ph.D. d i s s e r t a t i o n , D e p a r t m e n t of A g r i e u l t u r a 1 E c o n o m i c s , M i c h i g a n S t a t e U n i v e r s i t y , 1960. We st, J . G. " E s t i m a t e s of I n c o m e E l a s t i c i t y of C o n s u m e r Panel Data." U n p u b l i s h e d Ph.D. d i s s e r t a t i o n , D e p a r t m e n t of A g r i c u l t u r a l E c o n o m i c s , M i c h i g a n S t a t e U n i v e r s i t y , 1958. Wold, U ., an d J u r e e n , L. Demand Econometrics. N e w York: "The A p p r o x i m a t e D e t e r m i n a t i o n of S u r f a c e s by M e a n s of E n g e l C u r v e s . " Vol. 8 (1940), pp. 144-46. Indifferences Econometrica, Analysis: A S t u d y in J o h n W i l e y & S o n s , T95 3, Wood b u r ’ y , P. M. "Economic Consu mption Scales and Their U s e s . " J o u r n a 1 of A m e r i c a n S t a t i s t i c a l A s s o c i a t i o n , D e c e m b e r , 19 4 4. Z i m m e r m a n , C. York: C. D. Consu mp ti on and Standard V a n N e s t r a u d , 19 36. of Living. New