This paper estimates the causal effects of family size on girls’ education in Mexico, exploiting prenatal son preference as a source of random variation in the propensity to have more children within an instrumental variables framework. It finds no evidence of family size having an adverse effect on education. The paper then weakens the identification assumption and allows for the possibility that the instrument is invalid. It finds that the effects of family size on girls’ schooling remain extremely modest at most. Families that are relatively large compensate for reduced per-child resources by increasing maternal labour supply.

This article is related to the working paper Empirically probing the quantity-quality model.