We study how unemployment shocks in the United States affect Mexican households’ migration decisions. We emphasize households at origin (as op-posed to individuals) as the decisionmaking units for migration decisions. We show that negative changes in US labor market conditions, which are diffused by household members at destination to those at origin, lead to heterogeneous migration responses by Mexican households that have members abroad. We argue that this heterogeneous response is driven by the relative magnitudes of income and substitution effects after a negative employment shock in the United States. While the income effect dominates the substitution effect for poor households, the opposite holds for richer households. These results also inform the literature on selection patterns in international migration, which suggests a new channel through which negative shocks in the host economy negatively affect the skill composition of subsequent migrants.