This was created in partnership with Environment for Development .
We estimate the effect of hydro-meteorological emergencies on internal migration in Costa Rica between 1995 and 2000. Nationwide, we find that an increase of one emergency in a canton significantly increases average migration rates from that canton, after controlling for several social, economic, climatic and demographic factors in both the canton of origin and destination. Moreover, when we separately analyze landslides and floods, we find that both increase migration. However, we also find that emergencies with the most severe consequences, those with lossof lives, decrease migration. The severity of the consequences may explain the differences in the sign of the effect in previous research. We also find that emergencies will significantly increase population in metropolitan areas. Less severe emergencies significantly increase migration toward metropolitan areas. More severe emergencies significantly decrease migration toward non-metropolitan areas. This is especially important in developing countries, where cities face problems associated with overpopulation.