Linkages among climate change, crop yields and Mexico–US cross-border migration

摘要: Climate change is expected to cause mass human migration, including immigration across international borders. This study quantitatively examines the linkages among variations in climate, agricultural yields, and people's migration responses by using an instrumental variables approach. Our method allows us identify relationship between crop yields without explicitly controlling for all other confounding factors. Using state-level data from Mexico, we find a significant effect of climate-driven changes on rate emigration United States. The estimated semielasticity with respect approximately −0.2, i.e., 10% reduction would lead additional 2% population emigrate. We then use explore potential magnitude future emigration. Depending warming scenarios used adaptation levels assumed, factors held constant, year 2080, climate induce 1.4 6.7 million adult Mexicans (or current aged 15–65 y) emigrate as result declines productivity alone. Although results cannot be mechanically extrapolated areas time periods, our findings are global perspective given that many regions, especially developing countries, experience projected warming.