Why does the health of Mexican immigrants deteriorate? New evidence from linked birth records

This study uses a unique dataset linking the birth records of two generations of children born in California and Florida (1970–2009) to analyze the mechanisms behind the generational decline observed in birth outcomes of children of Mexican origin. Calibrating a simple model of intergenerational transmission of birth weight, I show that modest positive selection on health at the time of migration can account for the initial advantage in birth outcomes of second-generation Mexicans. Moreover, accounting for the socioeconomic differences between second-generation Mexicans and white natives and the observed intergenerational correlation in birth weight, the model predicts a greater deterioration than that observed in the data. Using a subset of siblings and holding constant grandmother quasi-fixed effects, I show that the persistence of healthier behaviors among second-generation Mexican mothers can explain more than half of the difference between the model prediction and the observed birth outcomes of third-generation Mexicans.