Explaining the Hispanic Paradox: An Examination of the Out-Migration Effect on the Health Composition of the Mexican Immigration Population

Weiwei Zhang, Brown University

Immigrants have been consistently observed to enjoy more favorable health/mortality outcomes than natives, even after controlling for SES and other demographic and social factors. This paper examines the hypothesis that the foreign-born appear healthier because of a greater tendency for unhealthy persons to emigrate (commonly referred to as the “salmon bias” hypothesis). Using a new approach for estimating emigration rates, we explores the possibility that emigration among Mexican immigrants residing in the United States affects the assessment of their general health situation. The results generally support the salmon bias hypothesis, showing higher emigration rates for unhealthy foreign-born Mexicans compared with their healthy counterparts. This pattern holds for young and old Mexican immigrants. Gender differences show that the out-migration effect is stronger among female Mexican immigrants compared to males. Duration of residence does not appear to be related to health selectivity in emigration independent of age.