Association for Public Policy Analysis & Management

Migration and its effects remain to be a contentious topic of debate in developed countries. While these debates typically relate to cross-border migration, many climate scientists warn about increasing rates of internal migration driven by climate change. For example, a recent World Bank report concludes that climate change could force more than 143 million people to move within their countries by 2015 in just three regions of the world - Sub-Saharan Africa, South Asia and Latin America (Kumari Rigaud et al. 2018). In the United States, sea level rise could alone displace 13 million people by the end of this century (Hauer 2017). Therefore, it is critical to understand the effects of climate migrants on the communities that receive them to better assess the costs associated with climate change.

This study examines the spillover effects of internal climate migration due to severe natural disasters in the United States using the large influx of migrant students into Florida public schools in the aftermath of Hurricane Maria. I find significant adverse effects of the influx in the first year on existing student test scores, disciplinary problems, and student mobility that vanish entirely in the second year. Specifically, the findings indicate that a 5-percentage point increase in migrant share reduces existing student test scores by 4 to 6 percent of the standard deviation, increases student suspensions by 15 to 20 percent in middle and high school, and increases the likelihood that existing students leave their schools before the following school year by 7 percent in the first year. These adverse effects are mainly concentrated among existing students who were higher-performing on prior year tests. I also find evidence of schools reallocating resources – teachers in particular – in a compensatory fashion when faced with a large migrant influx, increasing the likelihood that higher-performing students are assigned to first-year teachers. These findings (a) suggest that the current cost estimates associated with severe natural disasters that solely focus on their direct costs likely underestimate the true costs of these disasters and (b) raise concerns about using migrant flows to identify peer effects in education.