Returns to Birthweight

Abstract

We use data on monozygotic twins to obtain improved estimates of the effect of intrauterine nutrient intake on adult health and earnings and thus to evaluate the efficacy of programs aimed at increasing birthweight. We use the results to evaluate the bias in cross-sectional estimates and to assess the proposition that health conditions play a major role in determining the world distribution of income. We show that there is considerable variation in the incidence of low birthweight across countries, and our estimates suggest that there are real payoffs to increasing body weight at birth. Increasing birthweight increases adult schooling attainment and adult height for babies at most levels of birthweight, but has no effect on adult body mass. The effect of increasing birthweight on schooling, moreover, is underestimated by 50x% if there is no control for genetic and family background endowments as in cross-sectional estimates. We also find evidence that augmenting birthweight among lower-birthweight babies, but not among higher-birthweight babies, has significant labor market payoffs. However, shifting the distribution of birthweights in developing countries to that in the United States would reduce world earnings inequality by less than 1%, far less than indicated by the cross-country correlation between per-worker GDP and birthweight. © 2004 President and Fellows of Harvard College and the Massachusetts Institute of Technology.

Weight of the Crisis: Evidence from Newborns in Argentina

“…Of course, in doing that, a note of caution is warranted. Although it is true that the twin estimates control for unobservable factors capturing the in utero environment (Behrman and Rosenzweig, 2004), they are based on a selected sample: the average birth weight and the proportion of LBW is much lower for twins.…”

Adolescent health and adult labor market outcomes

“…In particular, a number of studies in the economics literature have shown the importance of birth weight for outcomes such as education, earnings, and cognition (e.g., Currie and Hyson 1999;Behrman and Rosenzweig 2004; 1 The authors thank Janet Currie and seminar participants at Lund University, at the Health and Human Capital Workshop in Mannheim, at the RGS Doctoral Conference in Duisburg, at the RES Conference in Cambridge, at the ASHE Conference in Minneapolis, at the EEA Conference in Gothenburg and at the EALE Conference in Turin for useful comments and suggestions. We also thank Ingvar Ahlstrand and Björn Bäckstand at the National Service Administration for providing information on the enlistment data and procedure.…”

Genetic Interactions with Prenatal Social Environment

“…MZ twins hold constant genetic differences that may influence both birth weight and the outcome of interest. Behrman and Rosenzweig (2004) established that birth weight within identical twin pairs is unrelated to other observed measures in their data and illustrated a substantial distribution of birth-weight differences between identical twins. We then ask whether the treatment effect of low birth weight varies across twin pairs that are divergent on measured alleles.…”

“…Caloric deprivation, in turn, affects the fetus, with lasting impacts. One estimate asserts that in the developing world, birth weight (i.e., fetal nutrition) influences gross domestic product (Behrman and Rosenzweig 2004). Of course, in the population at large, there are multiple causes of low birth weight.…”