The impact of family size and sibling structure on the great Mexico–USA migration

We investigate the impact of fertility and demographic factors on the Great Mexico–USA immigration by assessing the causal effects of sibship size and structure on migration decisions within the household. We use a rich demographic survey on the population of Mexico and exploit presumably exogenous variation in family size induced by biological fertility and infertility shocks. We further exploit cross-sibling differences to identify the effects of birth order, siblings’ sex, and siblings’ ages on migration. We find that large families per se do not boost offspring’s emigration. However, the likelihood of migrating is not equally distributed within a household. It is higher for sons and decreases sharply with birth order. The female migration disadvantage also varies with sibling composition by age and gender.