The Effects of Poor Neonatal Health on Children's Cognitive Development

We make use of a new data resource, merged birth and school records for all children born in Florida from 1992 to 2002, to study the effects of birth weight on cognitive development from kindergarten through schooling. Using twin fixed effects models, we find that the effects of birth weight on cognitive development are essentially constant through the school career; that these effects are very similar across a wide range of family backgrounds; and that they are invariant to measures of school quality. We conclude that the effects of poor neonatal health on adult outcomes are therefore set very early.