Child malnutrition and school retardation in China

T h i s paper i s f o r d i s d i b u t i o n T h i s s e r i e s of u n r e f e r e e d w i t h i n t h e World Bank Group d i s c u s s i o n papers i s i n t e n d e d to o n l y . It should n o t be c i t e d i n provide an i n i t i a l c i r c u l a t i o n sf . any e x t e r n a l p v b l i c a t i o n work prepared under t h e a u s p i c e s of t h e P o p u l a t i o n and Human Resources Division. Comments are t h e r e f o r e v e r y welcome. The p a p e r s should n o t be c i t e d w i t h o u t c l e a r a n c e by t h e a u t h o r . The views e x p r e s s e d a r e n o t n e c e s s a r i l y t h o s e of t h e DPH8127 World Bank Group. P o p u l a t i o n and Human Resources D i v i s i o n D i s c u s s i o n Paper No. 81-27 CHILD MALNUTRITION AM) SCHOOL RETARDATION I N CHINA September 1981 t w P r e p a r e d by: Dean T. Jamison, DEDPH - * T h i s paper w a s prepared a s !&pplementary Paper I V t o Annex B ( " P o p u l a t i o n . H e a l t h and N u t r i t i o n " ) o f Report No. 3391-CHA, China: S o c i a l i s t Economic Development (The World Bank, J u n e 1981). I The World Bank Washington, DC 20433 U.S.A.  Abstract A v a i l a b l e d a t a s u g g e s t t h a t t h e r e remains a s u b s t a n t i a l number of mildly- t o moderately-malnourished c h i l d r e n i n China, p a r t i c u l a r l y i n r u r a l a r e a s . S t u d i e s i n o t h e r c o u n t r i e s have found t h a t , ambng o t h e r a d v e r s e C consequences, m a l n u t r i t i o n w i l l c a u s e a c h i l d t o be l e s s motivated t o a t t e n d s c h o o l and t o l e a r n more slowly w h i l e t h e r e . Data made a v a i l a b l e t o t h e World Bank's f i r s t economic m i s s i o n t o China (October-December, 1PSO) p e r m i t 4 a n e x p l o r a t o r y assessment of t h e e x t e n t t o which m a l n u t r i t i o n i n China a f f e c t s t h e s c h o o l p r o g r e s s of a f f e c t e d c h i l d r e n ; t h i s paper r e p o r t s t h e r e s u l t s of t h a t assessment. Data were a v a i l a b l e on t h e h e i g h t , weight, a g e and g r a d e l e v e l of o v e r 3,000 c h i l d r e n i n f i v e q u i t e d i f f e r e n t l o c a t i o n s i n China --urban B e i j i n g , t h e p r o v i n c i a l c a p i t a l s of Lanzhou and Nanjing, and r u r a l a r e a s i n t h e provinces (Gansu and J i a n g s u , r e s p e c t i v e l y ) of which Lanzhou and Nanjing - - a r e c a p i t a l s . These d a t a allow compuation of how f a r behind i n s c h o o l each c h i l d i s , r e l a t i v e t o where he should be g i v e n h i s age, a s w e l l a s t h e n u t r i t i o n a l s t a t u s v a r i a b l e s of height-for-age, weight-for-age, and weight- for-height. The paper then u s e s s t a n d a r d s t a t i s t i c a l nethods t o e s t i m a t e t h e impact of n u t r i t i o n a l v a r i a b l e s on school r e t a r d a t i o n . C h i l d r e n tend t o be up t o h a l f a g r a d e f u r t h e r behind i n r u r a l a r e a s t h a n i n t h e p r o v i n c i a l c a p i t a l s , and about t h e same amount f u r t h e r behind i n t h e p r o v i n c i a l c a -p i t a l s t h a n i n B e i j i n g . Even a f t e r c o n t r o l l i n g f o r l o c a t i o n , however, lower n u t r i t i o n a l s t a t u s ( p a r t i c u l a r l y height-for-age) a d v e r s e l y a f f e c t e d s c h o o l performance; a one s t a n d a r d r e d u c t i o n i n height-for-age, t o t a k e a n example, would r e s u l t i n a child's being about 1 / 3 of a y e a r f u r t h e r behind. Though r e s u l t s from a g e o g r a p h i c a l l y l i m i t e d sample should be g e n e r a l i z e d only w i t h s u b s t a n t i a l c a u t i o n , i t d o e s appear l i k e l y t h a t m a l n u t r i t i o n i n - China h a s been s u f f i c i e n t l y p r e v a l e n t - t o r e t a r d - t h e s c h o o l advancement of l a r g e numbers o f c h i l d r e n . Contents  CHILD MALNUTZITION AN U CHINA* D SCHOOL RET.4RDATION L Introduction A v a i l a b l e evidence concerning t h e e x t e n t of c h i l d m a l n u t r i t i o n i n China has been reviewed i n a paper t h a t accompanies t h i s one./l While t h e r e was no i n d i c a t i o n of severe m a l n u t r i t i o n i n any of t h e r e g i o n r f o r which d a t a were a v a i l a b l e , t h e e x i s t e n c e of widespread moderate m a l n u t r i t i o n was documented. The e x t e n t and s e v e r i t y of m a l n u t r i t i o n v a r i e d i n t h e p r e d i c t a b l e way- urban a r e a s a r e s u b s t a n t i a l l y b e t t e r o f f than r u r a l ones; high-income r u r a l a r e a s a r e b e t t e r off than low income ones; and Horthern provinces appear t o be b e t t e r o f f than Southern ones. The prevalence of moderate m a l n u t r i t i o n r a i s e s the q u e s t i o n of t h e e x t e n t t o which i t s e x i s t e n c e is a matter of concern. While s e v e r e m a l n u t r i t i o n is a source of misery (and f r e q u e n t l y death) t h e adverse consequences of moderate m a l n u t r i t i o n a r e l e s s immediately e v i d e n t . An i n c r e a s i n g s t o c k of c a r e f u l e m p i r i c a l r e s e a r c h has, however, concluded t h a t a child's f a i l u r e t o grow adequately, i n comparison t o his g e n e t i c p o t e n t i a l , provides evidence of t h e e x i s t e n c e of o t h e r problems. F i r s t , as with s e v e r e l y malnourished c h i l d r e n , but t o a l e s s e r e x t e n t , moderately malnourished c h i l d r e n succtlmb more r e a d i l y t o i l l n e s s ; and, when ill, they a r e more l i k e l y t o d i e . Second, malnourished c h i l d r e n have lower l e v e l s o f ' a c t i v i t y and play than do vell-nourished c h i l d r e n . For a d u l t s , lower a c t i v i t y l e v e l s r e s u l t i n lower p r o d u c t i v i t y ; f o r c h i l d r e n t h e r e is an adverse e f f e c t on s o c i a l and mental development. F i n a l l y , t h e r e s e a r c h i n d i c a t e s t h a t moderate a a l n u t r i t i o n can l e a d t o reduced school performance. T h i s may r e s u l t from d i r e c t undernourishment of t h e b r a i n , and i t may r e s u l t * Ms. Kalpana Nandwani provided e x p e r t r e s e a r c h a s a i s t a n c e i n t h e p r e p a r a t i o n of t h i s paper - B - 1/ See "Food A v a i l a b i l i t y and t h e N u t r i t i o n a l S t a t u s of childre; i n China", by D.T. Jamisan, T.J. Ho, and F.R. Trowbridge. Washington, DC.: The World Sank, Populatdon and Human Resources D i v i s i o n Discussion Paper 81-26, September 1981. from t h e reduced energy and a c t i v i t y l e v e l s j u s t r e f e r r e d t o ; i n any c a s e - t h e e f f e c t s , though p o t e n t i a l l y i n p a r t r e v e r s i b l e , a r e g e n e r a l l y l a s t i n g - J l While t h e r e a p p e a r s t o have been no r e s e a r c h i n China on t h e e f f e c t s of m a l n u t r i t i o n on mental development o r s c h o o l performance,/2 d a t a made a v a i l a b l e t o t h e World Bank's r e c e n t economic mission t o China - (0ct.-Dec., 1980) allow assessment of one important f a c e t of t h i s i s s u e : Do poorly nourished c h i l d r e n f a l l behind o t h e r s i n s c h o o l by f a i l i n g g r a d e s or, perhaps, by e n t e r i n g s c h o o l l a t e ? T h i s paper r e p o r t s on t h e a n a l y s i s of the available data. The Data The M i n i s t r y of Education i n B e i j l i g and t h e p r o v i n c i a l b u r e a u s of e d u c a t i o n i n Gansu and J i a n g s u were w i l l i n g , a t t h e economic mission's r e q u e s t , t o g a t h e r h e i g h t , weight, and age d a t a on a l l t h e c h i l d r e n i n a l i m i t e d number of elementary s c h o o l s (two i n urban a e i j i n g , one i n Lanzhoa (Gansu), one i n Nanjing ( J i a n g s u ) , t h r e e i n r u r a l Gansu, and t h r e e i n r u r a l J i a n g s u ) . While t h e s c h o o l s were n o t randomly s e l e c t e d , t h e r e s p o n s i b l e o f f i c i a l s d i d a g r e e t o sample schools t h a t were n e i t h e r u n u s u a l l y good n o r - 11 There i s a n i n c r e a s i n g l y well-developed l i t e r a t u r e concerning t h e a d v e r s e f u n c t i o n a l consequences of m a l n u t r i t i o n ; Alan Berg and D o r i s Callaway provide reviews of t h e evidence concerning t h e c o s t s of m a l n u t r i t i o n f o r mental development, r e s i s t a n c e t o d i s e a s e , economic p r o d u c t i v i t y , and o t h e r f u n c t i o n s . Two o t h e r a n a l y s e s , by Myron Winick and by Joaquin C r a v i o t o and E l s a D e l i c a r d i e , p r o v i d e more narrow reviews on t h e r e l a t i o n between m a l n u t r i t i o n and mental development. While i t Zs d i f f i c u l t t o s e p a r a t e t h e e f f e c t s of m a l n u t r i t i o n p e r s e from o t h e r a s p e c t s of a deprived environment, t h e evidence does s t r o n g l y s u g g e s t t h a t m a l n u t r i t i o n r e t a r d s mental development n o t only through ( i n extreme c a s e s ) s t r u c t u r a l l e s i o n s of t h e b r a i n , b u t , probably more i m p o r t a n t l y , t h o u g h l o s s o f l e a r n i n g time, i n t e r f e r e n c e w i t h l e a r n i n g a t c r i t i c a l p e r i o d s , and r e d u c b g motivation. (See A. Berg, X a l n o u r i s h e d People: A P o l i c y View, Washington, D.C.: The World Bank, June 1981, pp. 9-15; D o r i s Callaway, "Functional Consequences of M a l n u t r i t i o n , " Workshop on I n t e r a c t i o n s of P a r a s i t i c D i s e a s e s and M a l n u t r i t i o n , B e l l a g i o , S e p t . 9 c t . 1980; Joaquin C r a v i o t o and E l s a D e l i c a r d i e , " N u t r i t i o n , M e n a l Development, and Learning, " i n F F a l k n e r and . J. H. Tanner, e z i t i o r s , Human Growth, Volume 3 Neurobiology and N u t r i t i o n , New B r k and London, Plenum P r e s s , 1977, pp. 481-511; a n d Myron Winick, M b l n u t r i t i o n and Brain Development, New York and London, Oxford U n i v e r s i q P r e s s , 1976, pp. 128-155. ) - 12 A r e c e n t review mentions no r e l e v a n t s t u d i e s ; s e e "Review of R e c e n t l y Published Work Dealing w i t h N u t r i t i o n Research i n Mainland China," by R.L. Freedman, Wld. Rev. Nutr. D i e t , vol. 30, 1978, pp. 1-22. ~46400/J84063/DlOll/23 - 3 - u n u s u a l l y poor; t h e re:ul'.ing d a t a , on o v e r 3 , 0 0 0 c h i l d r e n , p r o v i d e a r i c h s o u r c e f o r e x a m i n a t i o n o t r e g i o n a l n u t r i t i o n d i f f e r e n c e s and f o r t h e e f f e c t of m a l n u t r i t i o n on g r a d e a t t a i w n e n t . . - The measures of n u t r i t i o n a l s t a t u s t h a t a r e used i n t h e a n a l y s i s a r e c o n s t r u c t e d from h e i g h t , w e i g h t , and a g e t o g i v e height-for-age, weight- for-age, and weight-for-height ( f o r d e f i n i t i o n s o f t h e s e v a r i a b l e s s e e f o o t n o t e /a of T a b l e 2). The sample o f c h i l d r e n showed s u b s t a n t i a l malnu- t r i t i o n b y o n e common s t a n d a r d , 'stunting', which i s d e f i n e d a s h a v i n g a h e i g h t l e s s t h a n 90% o f t h e (United S t a t e s ) median For c h i l d r e n of t h e same a g e and sex. About 35% of c h i l d r e n i n r u r a l Gansu were s t u n t e d ; a t t h e o t h e r extreme, fewer t h a n 1% o f c h i l d r e n i n u r b a n B e i j i n g were s t u n t e d . /l I n a completely a d q u a t e l y n o u r i s h e d p o p u l a t i o n t h e u s e o f a v a r i a b l e liG h e i g h t t o p r e d i c t s c h o o l performance i s l i k e l y t o be a poor measure f o r a s s e s s i n g t h e e f f e c t of m a l n u t r i t i o n , s i n c e g e n e t i c f a c t o r s predominate. When, however, t h e r e i s s u b s t a n t i a l m a l n u t r i t i o n , s h o r t n e s s o f s t a t u r e (though p a r t i a l l y g e n e t i c a l l y d e t e n i n e d ) i s a good i n d i c a t o r of malnu- trition.- /2 S i n c e t h e d a t a on e a c h c h i l d i n c l u d e d h i s g r a d e a s w e l l a s h i s age one can c a l c u l a t e t h e a g e d i s t r i b u t i o n of c h i l d r e n by g r a d e ( T a b l e 1 ) a s w e l l a s , f o r e a c h c h i l d , a n i n d i c a t o r o f 'grades behind'./3 A c h i l d c a n be behind, of c o u r s e , e i t h e r because h e e n t e r e d s c h o o l l a t e or because h e h a d t o r e p e a t one o r more g r a d e s . B h i l e we have no d i r e c t e v i d e n c e c o n c e r n i n g t h i s on a child-by-child b a s i s , w e e x p e c t t h a t most o f t h e r e a s o n f o r b e i n g behind i s r e p e t i t i o n . F o r example, a t s r u r a l e l e m e n t r y s c h o o l i n T i n g X i County, Gansu, which was v i s i t e d by members o f t h e m i s s i o n , 13% of a l l c h i l d r e n were r e p e a t e r s and 25X o f t h e f i r s t - g r a d e r s were; t h i s was n o t viewed a s a t y p i c a l . From T a b l e 1 i t i s c l e a r t h a t l a r g e numbers o f c h i l d r e n a c t u a l l y are behind. Fewer a r e behind i n B e i j i n g t h a n i n the o t h e r c i t i e s , and f e w e r t h e r e t h a n i n t h e r u r a l s c h o o l s ; s t i l l , even i n B e i j i n g , o v e r h a l f t h e c h i l d r e n i n f i r s t g r a d e a r e 8 o r o l d e r . T a b l e 2 shows t h e means and s t a n d a r d d e v i a t i o n s o f a l l t h e v a r i a b l e s used i n t h e a n a l y s i s o f f a c t o r s influencing grade retardation. . e - /1 See Ho, Jamison, and Trowbridge, op c i t , forzmore d e t a i l e d d i s c u s s i o n o f t h e a n t h r o p o m e t r i c d a t a . While r e s e r v a t i s n s a r e i n o r d e r a b o u t u s i n g a U n i t e d S t a t e s s t a n d a r d t o measure t h e p r e v a l e n c e of s t u n t i n g i n China, t h e a n a l y s i s h e r e i s u n a f f e c t e d by=the s t a n d a r d c h o s e n s i n c e o n l y r e l a t i v e h e i g h t s o r w e i g h t s a f f e c t t h e *egression r e s u l t s . m - /2 S e e Winick, op. c i t . , p.142. - /3 The 'grades behind' v a r i a b l e i s simply t h e g r a d e a c h i l d s h o u l d be i n , g i v e n h i s age, minus h i s a c t u a l grade.  ~46400/~83922/~1011/24 - 4 - Grade I Table 1 : A School Gansu (Lanzhou) GE DISTRIBUTION BY GRADE: CHINESE PRIMARY SCHOOLS, B e i j i n g (urban) Gansu ( r u r a l ) OCTOBER-NOVEMBER, 1980 - N/a 84 25 160 -45 40 10/b - 51 36 34 4 20 26 21 - 4 - - 6 e - - 1 - - 1 - - - - - - J i a n g s u (Nanjing) 59 78- 14 5 2 2 - - - - Jiangsu ( r u r a l ) 91 20 60 14 2 3 - - .- - I1 B e i j i n g ( u r b a n ) 29 66 31 3 - - - - - - Gansu (Lanzhou 30 - 30 57 7 3 3 - - - Gansu ( r u r a l ) 107 - 4 18 38 26 9 4 - - Jiangsu(Nanjing) 80 10 48 23 10 6 1 3 - - Jiangsu ( r u r a l ) 71 - 10 30 41 18 1 - - - I11 B e i j i n g (urban) 132 3 17 30 44 5 1 - - - Gansu (Lanzhou) 34 - 3 3 59 27 9 - - - Gansu ( r u r a l ) 119 - 1 4 13 34 29 11 2 - 5 J i a n g s u (Nanjing) 86 - 2 48 33 9 7 1 - Jiangsu ( r u r a l ) 74 - 18 30 26 19 7 1 - - IV B e i j i n g (urban) 137 - - 20 51 23 5 - - - - Gansu (Lanzhou 34 - - - 3 47 47 3 - Gansu ( r u r a l ) , 103 - - 1 4 6 31 33 13 E3 J i a n g s u (Nanjing) 79 - - 4 37 33 16 9 1 Jiangsu ( r u r a l ) 94 - - 1 23 38 23 14 - - V B e i j i n g (urban) 148 - - - 1 14 46 38 1 . - Gansu (Lanzhou 31 - - - - - 45 55 - - Gansu ( r u r a l ) 57 - - - - - 7 33 25 35 J i a n g s u (Nanjing) 44 - - - a- 45 41 9 5 - Jiangsu ( r u r a l ) 96 - - - 1 14 66 18 - - - /a N i s t h e number of s t u d e n t s measured from t h e i n d i c a t e d group of s c h o o l s . -* /b T h i s i n c l u d e s one six-year old. - L - Note: E n t r i e s i n t h e tabla-=(row t h e p e r c e n t of c h i l d r e n of each g r a d e t h a t a r e of t h e i n d i c a t e d a g e ; a g e was c a l c u l a t e d from t h e d a t e of t h e c h i l d ' s - * birth. Source: X i s s i o n t a b u l a t i o n s from d a t a on s p e c i f i c ( n o t n e c e s s a r i l y r e p r e s e n t a - t i v e ) s c h o o l s s u p p l i e d by t h e M i n i s t r y o f E d u c a t i o n and t h e E d u c a t f o b Bureaus of Gansu and J i a n g s u p r o v i n c e s . C46400/ 5839221Dl0111 29-30 - 5 - Table 2: XEKG AND STANDXRD DEVIATIONS OF V-ARIABLES l EE ANALYSIS USED E Schools I n aural Rur a f Varlable sample B e i jing ?Tanj i n g Lanzhou Jiangsu Gansu T o t a l Sample Weight f o r age /a 87.27 93.99 86.13 a7 .?9 82.31 85 . O f (17.32) (17.68) (12.04) (11.58) (11.54) (18.21) Height f o r age /a 93.98 100.64 95.62 95.13 92.75. 91.76 (6.44) (4.99) (4.13) (4.17) (b.28) (6.33) Sex ( 1 = male 0.52 0.54 0. a9 0.56 0.52 0.5L ( 0 a female (0.50) (0.50) (0.50) (0.50) (0.50) (0.50) Age ( s o n t h s ) 120.84 114.00 114.58 11n.58 122.65 123.94 (22.95) (21.85) (21.95) (21.14) (20.54) (23.51) Grade 2.98 3-45 2.91 3.10 3.08 2.81 (1.38) (1.37) (1.28) (1.37-) (1.46) (1.34) Grade d e v i a t i o n 1.56 0.52 1.10 1.27 2.40 1.96 (1.22) (0.93) (1.09) (0.79) (1.29) (1.173 Y = Sample s i z e 3,149 530 348 154 426 1,691 Wefght f o r age /a 94.67 102.52 91.C9 91.69 89.49 94.21 (19.02) (15.91) (10.34) (10.29) (12.59) (22.75) Heightforagek 93.24 101.71 96.32 95.04 94.70 92.69 (6.42) (4.64) (3.88) (4.28) (4.51) (6.48) Weight f o r h e i g h t /a 106.08 97.49 98.91 103.07 101.56 112.79 (23.87) (9.93) (8.26) (8.96) (11.73) (30d86> Sex ( 1 a male 0.51 0.55 0.52 0.56 0.50 0.48 (0 a female (0.50) (0.50) (0.50) (0.50) (0.50) (0.50) Age (months) 94.76 91.48 92.39 95 .OO 96.70 96.25 (8.68) (10.10) (10.13) (9.00) (6.42) (7.58) Grade 1.66 2.15 1.74 1.T8 1.54 1.48 (0.83) (1.11) (0.72) (067) (0.83) (0.66) Grade d e v i a t i o n 0.68 -0.12 0.40 0.67 0.93 1.OL (0.84) (0.83) (0.60) (0.68) (0.73) (0.74B N = Sample s i z e 1,015 198 137 52 122 509 - /a These v a r i a b l e s a r e expressed as percent of the median value f o r a l a r g e sample of U S c h i l d r e n surveyed, t o e s t a b l i s h s t a n d a r d s , by t h e US National Center f o r Aealth S t a t i s t i c s ; t h e r e s u l t s a r e r e f e r r e d to as SCHS s t a n d a r d s , Note: E n t r i e s Fn t h e t a b l e a r e means v i t h s t a n d a r d d e v i a t i o n s shorn f n p a r e n t h e s i s belov. X a l n u t r i t i o n and Grade X e t a r d a t i o n T a b l e s 3 and 4 show t h e r e s u l t s of r e g r e s s i o n a n a l y s e s p r e d i c t i n g g r a d e d e v i a t i o n from a v a i l a b l e d a t a . I n e a c h c a s e t h e dependent v a r i a b l e i s t h e c h i l d ' s 'grades behind', and t h e r e g r e s s i o n s examine t h e e f f e c t of s e v e r a l v a r i a b l e s on 'grades behind'. I n Table 3 t h e v a r i a b l e s include weight-for-age, height-for-age, a g e , s e x , and t h e l o c a t i o n of t h e c h i l d - urban B e i j i n g , r u r a l J i a n g s u , etc. The l o c a t i o n v a r i a b l e a r e ( 0 , 1 ) 'indicator' v a r i a b l e s , e.g. t h e v a r i a b l e 'Beijing' t a k e s on t h e v a l u e "1" f o r z c h i l d i f h e i s from B e i j i n g and "0" o t h e r w i s e . I n T a b l e 4 weight- f o r - h e i g h t i s a l s o i n c l u d e d . Only younger c h i l d r e n ( n i n e y e a r s of a g e o r younger) a r e i n c l u d e d i n t h e a n a l y s e s r e p o r t e d i n T a b l e 4 ; t h i s is because n u t r i t i o n i s t s f e e l t h a t weight-for-height, which i n d i c a t e s how heavy a c h i l d i s r e l a t i v e t o o t h e r c h i l d r e n of t h e same h e i g h t , is a poor v a r i a b l e f o r c h i l d r e n i n o r approaching adolescence. Columns 1 and 2 o f T a b l e 3 show v e r y c l e a r l y t h e d i f f e r e n c e s among l o c a t i o n s i n g r a d e d e v i a t i o n t h a t were a p p a r e n t a l s o i n T a b l e 1. The c o e f f i c i e n t s f o r each region show t h e g r a d e d e v i a t i o n t h e r e r e l a t i v e t o B e i j i n g (which t h e r e f o r e has z e r o s a t t h e a p p r o p r i a t e e n t r i e s i n t h e t a b l e ) . The c o e f f i c i e n t on r u r a l Gansu, f o r example, shows t h a t c h i l d r e n t h e r e a r e on t h e a v e r a g e about 1 g r a d e f u r t h e r behind than a r e c h i l d r e n i n . B e i j i n g . The c o e f f i c i e n t on a g e shows, a s one would e x p e c t , t h a t o l d e r c h i l d r e n have f a i l e d more. The n e g a t i v e c o e f f i c i e n t s on weight-for-age and height-for-age i n columns 1 and 2 show t h a t t h e h i g h e r a c h i l d ' s n u t r i t i o n a l s t a t u s by e i t h e r of t h o s e measures t h e less f a r behind he i s l i k e l y t o be i n s c h o o l ; b o t h v a r i a b l e s a r e h i g h l y s t a t i s t i c a l l y s i g n i f i c a n t . The e f f e c t of h e i g h t i s p a r t i c u l a r l y s t r o n g , with a one s t a n d a r d d e v i a t i o n improvement i n h e i g h t b e i n g a s s o c i a t e d w i t h a c h i l d ' s b e i n g about 0.3 y e a r s less f a r behind. The remaining colums of T a b l e 3 r e p e a t t h e a n a l y s i s f o r t h e - p r o v i n c i a l subsamples; / l t h e same g e n e r a l p a t t e r n of f i n d i n g s a p p e a r s i n each. I n T a b l e 4 weight-for-height i s added t o t h e analyst&, $ath o n i t s own and i n c o n j u n c t i o n w i t h height-for-age. To t h e e x t e n t t h a t m.1- n u t r i t i o n ' s e f f e c t on s c h o o l p r o g r e s s i s b e s t c a p t u r e d ' b y a n i n d i c a t a r o f long-term, c h r o n i c m a l n u t r i t i o n t h e n height-for-age (and, t o a s l i g h t l y l e s s e r e x t e n t , weight-for-age) s h o u l d be b e t t e r p r e d i c t o r s of g r a d e d e v i a t i o n t h a n i s weight-for-height. T h i s i s g e n e r a l l y borne o u t i n t h e r e s u l t s of T a b l e 4 , where t h e c o e f f i c i e n t on weight-for-height i s sometimes 2 - /l A l l c h i 8 r e n from Bei j i n g a r e from t h e urban p a r t of t h e P m v i n c e . Both r u r a l and urban c h i l d r e n a r e r e p r e s e n t e d i n ty'e Gansu and J i a n g s u subsamples , and t h e a n a l y s e s f o r t h o s e subsamples t h u s i n c l u d e i n d i c a t o r v a r i a b l e s t o show whether r u r a l - u r b a n d i f f e r e n c e s e x i s t w i t h i n t h e s e provinces.  Table 3:: HEIGHTS AND WEIGHTS A S FACTORS INFLUENCING SCHOOL R E T A ~ D A T I O N (DEPENDENT VARIABLE IS 'GRADES BEIIIND') - - - D A l l schools Bei j i n g schools Gansu schools Jiangsu schools Explanatory variables Weight f o r age -0.004* -0.002 -0.002 -0.016* (4.22) (0.94) (1.85) (5.78) tleiglrt f o r age y0.029* -0.020* -0.027* -0.055* ($1.39) (3.15) (8.94) (7.67) Sex 1 = male 0.066" 0.063" 0.085 0.090 0.077* -0.08 0.020 0.002 0 = female (2.28) (2.23) (1.39) (1.49) (1.99) (2.10) (0.34) (0.03) Age ( i n months) O.O3i* 0.031* 0.028" 0.027* 0.033* 0.033" 0.026* 0.027* (45.96) (49.33) (19.40) (18.89) (37.67) (41.41) (17.68) (18.99) Gansu 0.527* 0.412* 0.000 0.000 (Lanzhou) (7.11) (5.60) Gansu 1.111* 0.907* 0.579" 0.493* (Rural) (26.57) (20-01) (8.39) (7.22) Jiangsu 0.513" 0.-417* 0.000 0.000 (Nanjing) (9.07) (7.47) , Jiangsu 0.772* 0.607* 0.253" 0.153" (Rural) (14.24) (11.02) (4.20) (2.43) Constant -2.676 0.124 -2.338 -0.435 -2.577 0.180 -0.566 3.234 t Note: The number i n parenthesis is #he t-value; coefficients significant a t the0.05 l e v e l arz irfirksd 4. p o s i t i v e , sometimes negative, and sometimes s t a t i s t i c a l l y i n s i g n i f i c a n t It . i s perhaps i n t e r e s t i n g t o n o t e t h a t weight-for-height tends t o be h i g h e s t i n r u r a l Gansu and J i a n g s u , where r e t a r d a t i o n l e v e l s a r e h i g h e s t and height- for-age i s lowest. The a n a l y s e s r e p o r t e d h e r e a r e based on d a t a s e t s t h a t provide no information on the .:hildsens' t.ome ~ n v i r o n m e n t . It i s c e r t a i n l y p l a u s i b l e t h a t f e a t u r e s of the home environment t h a t may be a s s o c i a t e d with lower nutritional levels - such a s lower income l e v e l s , lower p a r e n t a l education l e v e l s , poorer hygiene, and a g r e a t e r need f o r t h e c h i l d t o work - may a l s o be d i r e c t l y a s s o c i a t e d with poorer school performance. I n a d d i t i o n , t a l l e r c h i l d r e n nay simply be perceived a s more mature and be nore l i k e l y t o be piornoted t o t h e next grade f o r t h a t reason a l o n e . Thus t h e f i n d i n g t h a t lower n u t r i t i o n a l l e v e l s a r e ~ s s o c i a t e d w i t h poor performance i n school nay - i l d e e d , probably does - p a l - i a l l y r e f l e c t t h e c o r r e l a t i o n of n u t r i t i o n with t h e s e o t h e r v a r i a b l e s . On t h e o t h e r hand t h e r e is r e l a t i v e l y l i t t l e v a r i a t i o n i n those o t h e r v a r i a b l e s w i t h i n a n a r e a served by a few elementary s c h o o l s , and t h e l i t e r a t u r e from o u t s i d e China -?ports adverse e f f e c t s of m a l n u t r i t i o n on school p e r f o r - snce. W e thus i ; e r ~ - e t these r e s u l t s to suggest t h a t t h e r e i s a r e a l e f f e c t of n u t r i t i o n I- el on grade d e v i a t i o n , though i t is probably smaller than the c o e f f i c i e n t s i n Tables 3 and 4 i n d i c a t e . /A Conclusion There remains a s i g n i f i c a n t amourt of mild t o mo.ierate m a l n u t r i t i o n i n China, and t h e a n a l y s i s i n - h i s paper s u g g e s t s t h a t t h i s degree of m a l n u t r i t i o n a d v e r s e l y a f f e c t s stur!ents' school performance. Student i n r u r a l a r e a s were c o n s i s t e n t l y f u r t h e r behind i n school than s t u d e n t s i n urban c e n t e r s , and s t u d e n t s i n t h e p r o v i n c i a i c a p i t a l s of Lanzhou and Nanjing were f u r t h e r behind than s t c d e n t s i n Beijing. But, wherever t h e i r l o c a t i o n , c h i l d r e n low i n height-for-age were c o n s i s t e n t l y f u r t h e r behind. Children low i n weight-for-age b .A E a l s o behind, but weight was a l e s s good p r e d i c t o r than h e i g h t f o r r e t a r d a t i o n . There was nc c o n s i s t e n t e f f e c t of weight-for-height on r e t a r d a t i o n , which i s c c n s i s t e n t with f i n d i n g s elsewhere t h a t , except f o r extreme low v a l u e s , there*%y be l i t t l e disadvantag4 a s s o c i a t e d with lower weight-for-height. Though r e s u l t s from a g e o g r a p h i c a l l y l i m i t e d sample should be g e n e r a l i z e d only with c a u t i o n , i t does appear t h a t m a l n u t r i t i o n i n China i s s u f f i c i e n t l y p r e v a l e n t t o r e t a r d the school advancement of l a r g e n m b e r s of c h i l d r e n . 11 - It i s perhaps worth n o t i n g e x p l i c i t l y a t t h i s p o i n t t h a t , s i n c e t h e d a t a discussed h e r e were c o l l e c t e d from a school-based samble, t h e y do n o t permit a n a l y s i s of t h e e x t e n t t o which being malnourished i n c r e a s e s t h e p r o p e n s i t y t o drop o u t of s c h o o l a l t o g e t h e r . This e f f e c t could be important i n r u r a l a r e a s , and, t o t h e e x t e n t t h a t i t i s , i t would b i a s t h i s paper's r e s u l t s toward underestimating t h e impact of m a l n u t r i t i o n .  POPULATION & HUMAN RESOURCES DIVISION DISCUSSION PAPERS [A * by t h e number i n d i c a t e s t h e paper i s Bank-confidential o r otherwise r e s t r i c t e d . ] 81-1 Oey A. _Meesook, "Demographic C h a r a c t e r i s t i c s of I n d i v i d u a l s a & tke Measurement of Lifetime Income". February 1981. 81-2 Susan H. Cochrane, "The Economics of F e r t i l i t y with Examples fr- Asia". February 1981. 81-3 Rashid Faruqee, "Social I n f r h s t r u c t u r e and S e r v i c e s i n Zimbabweg- February 1981. 81-4* Richard Sabot, A. Berry, A. Hazlewood, J. Knight, J . Armitagt - a d M. B o i s i i e r e , " c o g n i t i v e S k i l l s : Their ~ e t e r m i n a n t sand influence on Earnings i n Two Psor Urban Economies. " P e b r u a w B9&ILI 81-5 Dean T. Jamison, Parbara S e a r l e . Stephen Heyneman, and Klaus Galdb "Improving Elementary Mathematics Educatibn i n Nicaragua: Bn Experimental Study of t h e Impact of Textbooks and Radio on Achievement". March 1981. 81-6 Rashid Faruqee, "Analyzing the Impact of Health Services: N a f l e d f -~ and Other Zxperiences". ,%rch 1981. 81-7 J. B. Knight and R. H. Sabot, "Labor Market Discrimination iar a Poo.1: Urban Economy". March 1981. 8 1 Oey A. Me~sook, " I n t e r r e l a t i o n s h i p s betwar7 Demographic F a c t o r s and Income D i s t r i b u t i o n : Problems of Measurement, D e s c r i p t i o n a d I n t e r p r e t a t i o n " . A p r i l 1981. 81-9 Susan H. Cochrane, Ninnala J o s h i and Kalpana Nandwani, " F e r t f U t l f A t t i t u d e s and Behavior i n t h e Nepal Terai". A p r i l 1981. 81-10 J . B . Knight and Richard Sabot, "The Role of t h e Firm i n Wage De€ermj.nation: * A . African Case Study". A ~ r i 1981. l - U 81-11 J.B. Knight and Richard Sabot, "The Returns t o Education: Z ~ ~ ~ r e a s h g with Experience o r Decreasing w i t h Expansion?". Karch 1981- - 81-12 J . B . Knight and Richard Sabot, "From Migrants t o p s l e t a r i - = Emplqment Experience, Mobility and Wages i n Tanza_niaW. M a ~ d z%WD. * 81-13 A. Develi~t.'"- Bepry and Richard Sabot, - "Unemployment and ~ c o n a i c L A p r i l 1981. 81-14 Rashid Faruqee and Ethna Johnson, "Health, N u t r i t i o n ancl F a d y Plamming: A Survey of Experime-ts and S p e c i a l P r o j e c t s i n India". A p r i l H48kl0 81-15 Francois O r i v e l and Dee,.: T. Jamison, "The Cos t-Ef f e c t i v e n e s s of Distance Teaching P r o j e c t s " . June 1981 81-45 Robert E.B. Lucas. "The D i s t r i b u t i o n and E f f i c i e n c y of Crop Production i n T r i b a l Areas o f Botswana." September 1981- 81-46 Robert E.B. Lucas. "The D i s t r i b u t i o n of Wages and Employment I n Rural Botswana." September 1981. Dov Chernichovsky. "Socioeconomic and Demolgraphic Aspects of Sch Enrollment and Attendance i n Rural Botswa.na. " Forthcoming. 81-43 Dov Chernichovsky. "Socioeconomic C o r r e l a t e s of F e r t i l i t y &haPf.or i n Rural Botswana. " Forthcoming. S h e r r i Kossaudji and Eva Mueller. "The Eca~nomicand Demographic S t a t u s of Female Headed Households i n Bot.swans." Forthcopfug. 81-50 Francois Orivel. "La TSlGvision S c o l a i r e du S6n6nal: E v a l ~ ~ a E i o a Economique e t Perspectives." Aout 1981. (summiry a v a i l a b l e i n English. ) H i l l a r y Perraton, Dean T. Jamison and Franc: o i s Orivel. "Mass Met3 f o r A g r i c u l t u r a l Extension i n Malawi". September 1981