"The United States produces 41% of the world's corn and 38% of the world's soybeans, so any impact on US crop yields will have implications for world food supply. We pair a panel of county-level crop yields in the US with a fine-scale weather data set that incorporates the whole distribution of...

"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...