Migration, Urbanization and Health

Abstract

Rural-to-urban migration is a significant driver of urbanization in the developing world. The motivations for rural-to-urban migration typically include economic and educational opportunities, but migrants – most of whom are young adults – may also move for personal reasons. Leaving the family home affords increased autonomy and anonymity, especially amidst the more permissive social norms in the city versus the village. The relationship between rural-to-urban migration and health involves three key mechanisms. First, the health status of migrants may differ from that of their non-migrant counterparts at origin before they move. Indeed, a healthy migrant phenomenon has been empirically shown. Second, rural-to-urban migration may affect physical and mental health status, because migrants are exposed to new risks and benefits in urban destinations. Finally, health status may determine which migrants stay at destination and which return to origin: less healthy migrants may be more likely to return. This selection mechanism has been called “salmon bias” in the literature, but we label it “Midnight Train” effect due to the apt description in the song’s lyrics about a musician who moved from his native Georgia to Los Angeles to become a “superstar, but he didn’t get far” and decides to “go back to the life he once knew.” Differentiating these three mechanisms presents formidable methodological challenges for studying the impact of migration on health. A longitudinal research design makes it possible to ascertain selection effects of rural-to-urban migration and return migration, and also to observe changes in health status that occur from pre- to post-migration.