"Extreme heat is the single best predictor of corn and soybean yields in the United States. While average yields have risen continuously since World War II, we find no evidence that relative tolerance to extreme heat has improved between 1950 and 2005. Climate change forecasts project a sharp...

"We investigate the link between agricultural productivity and net migration in the United States using a county-level panel for the most recent period of 1970-2009. In rural counties of the Corn Belt, we find a statistically significant relationship between changes in net outmigration and...

"Agriculture on the American Great Plains has been constrained by historical water scarcity. After World War II, technological improvements made groundwater from the Ogallala aquifer available for irrigation. Comparing counties over the Ogallala with nearby similar counties, groundwater access...