Climate Variability and Inter-State Migration in India

with Katrin Millock

We match climate data to migration data from the 1991 and 2001 Indian Censuses to investigate the impact of climate variability on internal migration. The article makes four contributions to the existing literature on macro-level migration flows. First, use of census data allows us to test and compare the effect on migration of climatic factors prior to migration. Second, we introduce relevant meteorological indicators of climate variability, to measure the frequency, duration, and magnitude of drought and excess precipitation based on the Standardized Precipitation Index. Third, we estimate the total effect (direct and indirect effects) of climate variability on bilateral migration rates. Fourth, we examine three possible channels through which climate variability might induce migration: average income, agriculture, and urbanization. The estimation results show that drought frequency in the origin state increases inter-state migration in India. This effect is stronger in agricultural states, and in such states the magnitude of drought also increases inter-state migration significantly. Drought frequency has the strongest effect on rural–rural inter-state migration.

JEL codes: O15, Q54.

Keywords: climate variability, drought, India, internal migration, PPML, SPI.