Moving beyond Salmon-Bias: Mexican Return Migration and Health Status

Christina Diaz, University of Wisconsin-Madison
Stephanie Koning, University of Wisconsin-Madison

Despite having lower levels of education and limited access to health care services, Mexican immigrants report better health outcomes than U.S.-born individuals. Existing work suggests that the Mexican health advantage may be partially attributable to selective return migration among less healthy migrants—also known as the salmon-bias hypothesis. Our study takes advantage of a rare opportunity to observe health at the precise time this proposed form of health selection occurs. We use the California Health Interview Survey and the Migrante Study, a survey of Mexican migrants entering and leaving the U.S. through Tijuana, to assess whether unhealthy immigrants are disproportionately represented among those returning to Mexico. We then consider two possible explanations that may be driving patterns of return migration. This study elucidates the relationship between health and migration decisions, and also provides useful considerations for future studies examining migration, selection, and health disparities.