We provide evidence that the occurrence of an international migration episode is associated with a variation in the living arrangements of the household members left behind. The migration of a married Mexican man typically induces his spouse and children to join the household of the wife's parents, a pattern that is at odds with the prevailing patrilocal norm. This change in living arrangements, which involves the extended family of the migrant, has two relevant implications for the analysis of the effects of paternal migration and remittances on the children left behind. First, it can give rise to an important heterogeneity in the effects of interest, which has not been explored in the migration literature. Second, it leads to attrition in longitudinal household surveys that is non-random with respect to potential outcomes.