Do Social Networks Moderate the Effect of Extreme Weather on Migration?

Abstract

Using retrospective household data collected in southwest Bangladesh, we examine whether social ties to migrants moderate the effects of extreme weather on first migrations. We consider both weak and strong forms of social ties for both domestic and international trips. We also examine differences across male and female household members. Discrete time event history models reveal that migrant social ties predict making a first trip and are stronger for international versus domestic moves. Heat waves and storms/floods are positively associated with males making domestic trips and negatively associated with domestic trips among females. However, the effects are small and not moderated by social ties. In contrast, for male international moves, the effect of heat waves is conditional on the prevalence of ties to other international migrants. In communities with a strong history of international migration, the chance of making a first trip declines as heat waves intensify. Those from communities with a lower prevalence of international migration are more likely to make a first international trip as heat waves reach 15–25 days, after which the risk of migrating declines. Together, these results suggest that migrant networks attenuate, rather than amplify, the relationship between extreme weather and international migration.