The Effect of Migrant Regularization on Labor Exploitation

This paper shows that granting migrants legal status reduces labor exploitation. We study Spain's 2005 large-scale regularization program, which granted legal status to 600,000 undocumented migrants. We proxy labor exploitation with hospitalizations for heat-related illnesses among working-age individuals, capturing exposure to hazardous working conditions in outdoor occupations. We implement a triple-difference design that exploits cross-provincial variation in pre-reform shares of undocumented migrants and temporal variation in extreme temperatures. Our results show that the incidence of heat-related hospitalizations during heatwaves declined significantly in provinces with greater exposure to the amnesty. Specifically, an additional day above 35°C became 3.3 percentage points less likely to result in heat-related hospitalization in highly exposed provinces, representing a 9.4% reduction relative to the pre-reform mean. Our findings demonstrate that migrant regularization is a powerful policy for improving worker well-being and reducing their vulnerability to extreme climatic events.