Many children in developing countries face severe nutritional and cognitive deficits right at the beginning of life. Estimates suggest that up to one-eighth of all children in developing countries are born malnourished (weighing less than 2.5 kilograms) and that a large percentage of children—47 percent in low-income countries—continue to be malnourished before the age of five. What makes these numbers greatly troubling is that the effects of malnutrition that persist past the second year of a child’s life are difficult to reverse.[1] Early malnutrition weakens children’s physical and cognitive potential and even their non-cognitive traits such as motivation and persistence, so it is costly for their future health, educational attainment, and socioeconomic success.[2]

Lasting benefits of early child development (ECD)

Starting at birth, improved nutrition yields benefits that cascade through life. It is estimated that 40 percent of the $510 in economic benefits obtained from preventing one child from being born at or below 2.5 kilograms is because preventing low birth-weight leads to higher cognitive abilities and greater productivity of children.[3]

Among pre-school children in Ecuador, better nutrition, as measured by higher hemoglobin levels, improves cognitive development, as measured by a child’s test performance. Moreover, this association is larger for an older sample of children (ages 4 1/2 and older) than for a younger sample (ages 3-4 1/2), suggesting that the association between nutrition and cognitive development becomes stronger as the child matures.[4]

Among pre-schoolers in the Philippines, a one-standard deviation increase in height raises their achievement test scores years later, an increase that is equivalent to completing eight more months of schooling and which implies a benefit-cost ratio of three or more.[5]

Among pre-schoolers in rural Zimbabwe, if the median pre-school child were as tall as the median pre-school child in a developed country, by adolescence this child would be 3.4 centimeters taller and would have completed an additional 0.85 grades of schooling.[6]

Two additional notes on the long-term gains of ECD: First, these findings are similar to those in industrial countries which have found lasting effects not only on education levels and earnings but also on welfare participation levels, criminal records, and probability of out‑of‑wedlock births.[7]

Second, the studies on the long-term consequences of early childhood nutrition are based on panel data that allow researchers to relate direct measurements of pre-school child health and nutrition to later measures of physical development and schooling attainment. Cross-sectional data are less useful as they often do not contain direct measurements of preschool child health and cannot distinguish whether factors that explain school outcomes or earnings have also determined early malnutrition.

Wars, famines, and economic crises imperils child development

Children who have experienced nutritional deprivations during civil wars, droughts, and economic crises suffer long-lasting effects. In Ethiopia, in communities with crop damage, child growth is reduced, especially among children less than two years of age.[8] In Zimbabwe, the long-term consequences of malnutrition as measured by height and years of school completed, as mentioned above, were a result of civil war and drought.

During the economic crisis in Peruin the late 1980s the infant mortality rate increased by 2.5 percentage points, an effect that can be traced back to declines in health service availability and use.[9] This finding complements research that shows malnutrition is lower when household income is higher. In the Philippines, a child’s socioeconomic background (as measured by parental education, wealth and height) is positively associated with the child’s physical and cognitive development.[10] In Ecuador, a child whose family falls at the 90^th percentile for wealth, maternal education and paternal education is predicted to perform better on a test by approximately two standard deviations than a child at the 10^th percentile for each of these variables.[11] However, other studies show that moderate income growth is not enough to eradicate malnutrition in poor countries.[12]

Integrated pre-school programs show promise

A combination of income growth and nutrition programs is likely to be the most effective for achieving the Millennium Development Goal for nutrition. Feeding and nutrient supplementation programs for infants and toddlers have been shown to be effective in improving children’s health and growth. For example, two evaluations of Mexico’s PROGRESA nutrition intervention found that newborns in treatment communities were 26 percent less likely to be anemic,[13] and that nutritional supplements for children 12-36 months increased mean growth per year by about a one-sixth, an impact that could raise lifetime earnings by 2.9 percent.[14]

But a number of developing countries have adopted programs that are multifaceted, including not only feeding and micronutrient supplementation, but also immunization, child growth monitoring, child care services, mental stimulation for children, as well as training of parents in parenting skills.

Three integrated programs have been carefully evaluated:

• An ECD pilot project in Jamaicastudied the test performance of stunted children aged 9 to 24 months.[15] Children were divided into four random groups—control, nutrient supplements only, stimulation only (play sessions with a community health aide), supplements plus stimulation—and a control group of matched non-stunted children. The evaluation found that stimulation and supplements had significant beneficial effects independent of each other, but that the interventions when combined were significantly more effective.
• At Bolivia’s Proyecto Integral de Desarrollo Infantil (PIDI), low-income children in urban areas between the ages of 6 to 72 months areas received full-time day care, nutritional supplements, and systematic learning environments. The evaluation compared children in the feeder areas not in the program, children in the program for less than one month, children living in similar areas without the program, and children who had more than seven months exposure to the program. The best positive cognitive and psychosocial outcomes were observed among children exposed to the program early in life and for more than a year. The effects imply gains in lifetime earnings consistent with fairly high benefit/cost ratios (1.7 to 3.7).[16]
• A pilot ECD program in the Philippinesincludes center–based interventions (day care services, pre-schools, and health centers) and home-based interventions (family day care programs, parenting classes, and home visits by ECD-focused workers). An evaluation found that, compared to children residing in non-program areas, there was significant improvement in weight-for-height Z scores among children age five and above, and in cognitive, social, and motor development among children aged three and below in the program areas. Distinguishing by duration of program exposure, among those exposed for more than 17 months, the proportion of children below age four with worms was significantly lower in program compared to non-program areas, and children of all ages showed improvements in psycho-social development.[17]

While these three programs have led to generally positive outcomes, evidence of their impact when they are implemented on a large scale is still limited.[18] Complex programs fail because they place large demands on implementation and financial capacity. For example, an evaluation of the Integrated Child Development Service in Indiaconcluded that the program was diluted by offering too many services (including supplementary feeding and early child education) to too wide an age bracket.[19]

Earlier is better

The returns from investing in early childhood development is the cumulative effect of early nutrition, health care, and cognitive stimulation, so interventions that start early, especially before the age of two, have the highest gain. Malnutrition tends to be most common and severe during the periods of greatest vulnerability—that is, at pregnancy and the first two to three years of life—and, if it persists into the second year of life, stunts cognitive development and is difficult to reverse.[20]

The findings on the Bolivia and the Philippinesprograms mentioned above illustrate the importance of early and long exposure to ECD programs. Two studies on African programs reach similar conclusions: A large-scale program in Madagascaryielded positive returns related to length of exposure to the project.[21] In communities with two additional years of exposure, very young children had 7-9 percentage-points lower malnutrition than children in communities with shorter treatment time. In Uganda, a similar project showed a significant increase in weight for children less than one year of age, but no increase for children aged two to five.[22]

These research findings reinforce the belief that investing in nutrition early reaps significant long-term dividends, mostly because a child’s physical and mental abilities develop most rapidly at this age. Impact evaluations also suggest that integrated programs—nutritional and health interventions, training in parenting skills, cognitive stimulation—although complex to implement, may produce the biggest benefits.

The findings, interpretations, and conclusions expressed in this paper are entirely those of the authors. They do not necessarily represent the view of the World Bank, its Executive Directors, or the countries they represent.

ELIZABETH M. KING is the Research Manager for the Human Development and Public Services team of the Development Research Group. Her main researcho interests have been the determinants of investments in human capital; the linkages among dimensions of human capital, poverty and economic development; and the impact of education reforms such as decentralization in developing countries. Several of her studies have examined also the significance of gender differences in the development process. Email c/o:research@worldbank.org

Related Resources

• Early Child Development. This site is a knowledge source designed to assist policymakers, program managers, and practitioners in their efforts to promote the healthy growth and integral development of young children.

• This article was based in part on a review article entitled "Early Childhood Development: A Review of Findings from a Longitudinal Study in the Philippines," by Sharon Ghuman, Jere R. Behrman, Socorro Gultiano, Graeme Armecin, Isabelita Bas, Paulita Duazo, Elizabeth M. King, and Nanette Lee, East Asian Economic Perspectives 17 (August), 2006. (Full text)

References

[ 1] P. Glewwe and E. M. King, “The Impact of Early Childhood Nutritional Status on Cognitive Development: Does the Timing of Malnutrition Matter?” World Bank Economic Review 15(1): 81-113, 2001.

[ 2] See J. Behrman, H. Alderman, and J. Hoddinott, “Hunger and Malnutrition,” in B. Lomborg, ed. , Global Crises, Global Solutions, Cambridge University Press, 2006; N. Schady, “Early Childhood Development in Latin America and the Caribbean,” Policy Research Working Paper 3869, World Bank, Washington, D.C., 2006; R. Martorell, “The Nature of Child Malnutrition and its Long-Term Implications,” Food and Nutrition Bulletin 20: 288-292, 1999; J. Strauss and D. Thomas, “Health, Nutrition and Economic Development,” Journal of Economic Literature 36(2):766-817, 1998; and J. Strauss and D. Thomas, “Human Resources: Empirical Modeling of Household and Family Decisions, in J. R. Behrman and T. N. Srinivasan, eds., Handbook of Development Economics, Volume 3, North-Holland, Amsterdam, 1995.

[ 3] H. Alderman and J. R. Behrman, “Reducing the Incidence of Low Birth Weight In Low-Income Countries Has Substantial Economic Benefits,” World Bank Research Observer 21(1):25-48, 2006.

[ 4] C. Paxson and N. Schady, “Cognitive Development among Young Children in Ecuador: The roles of Wealth, Health, and Parenting,” Policy Research Working Paper 3605, World Bank, Washington, D.C., 2005.

[ 5] P. Glewwe, H. Jacoby, and E. M. King, “Early Childhood Nutrition and Academic Achievement: A Longitudinal Analysis,” Journal of Public Economics 81(3): 345-68, 2001.

[ 6] H. Alderman, J. Hoddinott, and W. Kinsey, “Long Term Consequences of Early Childhood Malnutrition.” Oxford Economic Papers 58: 450-474, 2006.

[ 7] P. Carniero and J. Heckman, “Human Capital Policy,” National Bureau of Economic Research Working Paper 9495, February 2003; J. Heckman and Y. Rubinstein, “The Importance of Noncognitive Skills: Lessons from the GED Testing Program,” American Economic Review 91(2): 145-149, May 2001; S. B. Kamerman, “Early Childhood Education and Care: An Overview of Developments in the OECD Countries,” International Journal of Educational Research 33(1): 7-29, 2000.

[ 8] T. Yamano, H. Alderman, and L. Christiaensen, “Child Growth, Shocks, and Food Aid in Rural Ethiopia,” American Journal of Agricultural Economics 87: 273–288, 2005.

[ 9] C. Paxson and N. Schady, “Child Health and Economic Crisis in Peru,” World Bank Economic Review 19: 203-23, 2005.

[ 10] For a full exploration of effects of physical assets and the height and education of parents, see S. Ghuman, J. R. Behrman, J. B. Borja, S. Gultiano, and E. M. King, “Family Background, Service Providers, and Early Childhood Development in the Philippines: Proxies and Interactions,” Economic Development and Cultural Change 54(1, October): 129-164, 2005.

[ 11] C. Paxson and N. Schady, “Cognitive Development among Young Children in Ecuador: The roles of Wealth, Health, and Parenting,” Policy Research Working Paper 3605, World Bank, Washington, D.C., 2005.

[ 12] L. Haddad, H. Alderman, S. Appleton, L. Song, and Y. Yohannes, “Reducing Child Malnutrition: How Far Does Income Growth Take Us?” World Bank Economic Review 17(1): 107-131, 2003.

[ 13] P. Gertler, “Do Conditional Cash Transfers Improve Child Health? Evidence from PROGRESA’s Controlled Randomized Experiment.” Health, Health Care, and Economic Development 94(2): 336-341, 2004.

[ 14] J. R. Behrman and J. Hoddinott, “Programme Evaluation with Unobserved Heterogeneity and Selective Implementation: The Mexican PROGRESA Impact on Child Nutrition,” Oxford Bulletin of Economics & Statistics 67(4): 547, August 2005.

[ 15] S. M. Grantham-McGregor, C. A. Powell, S. P. Walker, and J. H. Himes, “Nutritional Supplementation, Psychosocial Stimulation, and Mental-Development of Stunted Children - The Jamaican Study,” Lancet 338(8758): 1-5, 1991.

[ 16] J. R. Behrman, Y. Cheng, and P. Todd, “Evaluating Preschool Programs when Length of Exposure to the Program Varies: A Nonparametric Approach,” Review of Economics and Statistics (February), 2004.

[ 17] G. Armecin, J. R. Behrman, S. Ghuman, S. Gultiano, E. M. King, and N. Lee, “Early Childhood Development through an Integrated Program: Evidence from the Philippines,” Policy Research Working Paper (forthcoming), World Bank, Washington, D.C, 2006.

[ 18] H. Alderman, “Linkages between Poverty Reduction Strategies and Child Nutrition: An Asian Perspective,” Economic and Political Weekly 40: 4837-42, 2005.

[ 19] M. Gragnolatti, C. Bredenkamp, M. Das Gupta, Yi-Kyong Lee, and M. Shekar, “ICDS and Persistent Undernutrition. Strategies to Enhance Impact,” Economic and Political Weekly (March 25-31): 1193-1201, 2006.

[ 20] P. Glewwe and E. M. King, “The Impact of Early Childhood Nutritional Status on Cognitive Development: Does the Timing of Malnutrition Matter?” World Bank Economic Review 15: 81 – 113, 2001.

[ 21] E. Galasso and J. Yau, “Improving Nutritional Status through Behavioral Change: Lessons from the SEECALINE Program in Madagascar,” Development Research Group, World Bank, Washington, D.C., processed, 2005.

[22] H. Alderman, “Improving Nutrition through Community Growth Promotion: Longitudinal Study of the Nutrition and Early Child Development Program in Uganda,” Development Research Group, World Bank, Washington, D.C., processed, 2006.