Leave for where? The impact of air quality on migration: Evidence at the city-pair level in China.

We comprehensively explore the question of "Leave for where?" by utilizing city-pair level data of China spanning from 2011 to 2017. Our investigation focuses on the impact of disparities in air quality between city pairs on migration. we find that a 1% increase in the difference air quality between inflow and outflow locations raises the number of people migrating from the outflow to the inflow location by approximately 0.07%. This finding is robust after overcoming possible endogeneity problems with average wind speed as an instrumental variable. In addition, we conducted a heterogeneity analysis in terms of intention to migrate and individual characteristics, finding that individuals who migrated for work and family are more sensitive to differences in air quality between city pairs, whereas those who moved for business are not sensitive to differences in air quality. Regarding individual characteristics, differences in air quality between city pairs have a greater impact on the migration decisions of low-educated, female, and younger migrants. Further, a mechanistic analysis by constructing cohort dummy variables reveals that poor air quality is more motivational than the desire for good air quality and the crowding-out effect of air pollution on migration is more pronounced.