Birth weight and school performance

This study investigates the long-term association between birth weight and school performance in Norway, with a focus on how this relationship has evolved alongside demographic changes. We contribute to the literature by examining this link in a contemporary context using nearly two decades of administrative data. Our findings indicate that higher birth weight is consistently associated with better school performance, particularly in mathematics. This association remains robust across multiple model specifications, including those that account for unobserved family heterogeneity. We also find a slightly stronger association among girls, though the gender interaction is small and not robust in the twin design. Overall, the results underscore birth weight as a stable predictor of academic achievement and highlight its relevance for understanding early-life determinants of human capital development.