Shock and roam: Migratory responses to natural disasters

•Use novel data on roaming cellphones to capture post-earthquake migratory responses.•Higher emigration emerges within a few weeks after the Ludian earthquake.•Quake-induced emigration peaks in about 14 weeks.

Using novel data on roaming mobile phones and a synthetic control method, we find out-migration in the area affected by the 2014 Ludian earthquake in Southwest China. The induced emigration emerged within a few weeks after the earthquake and persisted for months. We find no evidence that the earthquake drew back migrants who, prior to the earthquake, had emigrated to Guangdong province, which is a manufacturing hub and the primary destination of rural migrant workers in China.