The Impact of Global Warming on Rural-Urban Migrations: Evidence from Global Big Data

This paper examines the impact of temperature changes on rural-urban migration using a 56km×56km grid cell level dataset covering the whole world at 10-year frequency during the period 1970-2000. We find that rising temperatures reduce rural-urban migration in poor countries and increase such migration in middle-income countries. These asymmetric migration responses are consistent with a simple model where rural-urban earnings differentials and liquidity constraints interact to determine rural-to-urban migration flows. We also confirm these temperature effects using country-level observations constructed by aggregating the grid cell level data. We project that expected warming in the next century will encourage further urbanization in middle-income countries such as Argentina, but it will slow down urban transition in poor countries like Malawi and Niger.