Another Look at Returns to Birthweight

from Journal of Health Economics at on November 28, 2019 at 03:31PM

Publication date: Available online 27 November 2019

Source: Journal of Health Economics

Author(s): Maruyama Shiko, Heinesen Eskil


We revisit the causal effect of birthweight. Because variation in birthweight in developed countries primarily stems from variation in gestational age rather than intrauterine growth restriction, we depart from the widely-used twin fixed-effects estimator and employ an instrumental variable – the diagnosis of placenta previa, which provides exogenous variation in gestation length. We find protective effects of additional birthweight against infant mortality and health capital loss, such as cerebral palsy, but in contrast to sibling and twin studies, no strong evidence for non-health long-run outcomes, such as test scores. We also find that short-run birthweight effects have diminished significantly over the decades.