The Impact of Family Size and Sibling Structure on the Great Mexico-U.S. Migration

We investigate how fertility and demographic factors affect migration at the household level by assessing the causal effects of sibship size and structure on offspring's international migration. 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 birth order, sibling-sex, and sibling-age composition effects on migration. We find that large families per se do not boost offspring out-migration. Yet, the likelihood of migrating is not equally distributed within a household, but is higher for sons and decreases sharply with birth order. The female migration disadvantage also varies with sibling composition by age and gender.