Might climate change the healthy migrant effect?

Migrants from Mexico to the U.S. tend to be healthier than non-migrants in their origin part of a pattern termed the healthy migrant effect. With climate change altering livelihoods across the globe, we ask how the migration-health connection may be altered by environmental strain. On the one hand, positive health selectivity may be intensified if migration becomes more challenging and therefore increasingly likely to be undertaken by only the healthiest. On the other hand, positive health selectivity may decline if the push associated with environmental strain acts upon individuals regardless of health. We use Mexican Migration Project data to model Mexico-US migration by male household heads with consideration of migrant health as well as recent rainfall conditions in communities of origin. Results reveal intriguing interactions such that when moderately dry regions experience rainfall shortage, health selectivity is lower meaning that less healthy household heads also engage in international migration. We posit that social networks may underlie this association. We further argue that since environmental context may alter the relationship between migration and health, future research on the healthy migrant effect should consider environmental conditions. As to implications, if climate change yields pressure on less healthy individuals to migrate, the need for migrant-sensitive health systems and services may be intensified in destination regions.