Working Paper: NBER ID: w18659
Authors: Steven T. Berry; Michael J. Roberts; Wolfram Schlenker
Abstract: Corn prices increased sharply in the summer of 2012 due to expected production shortfalls in the United States, which produces roughly 40% of the world's corn. A heat wave in July adversely affected corn production. We extend earlier statistical models of county-level corn yields in the Eastern United States by allowing the effect of various weather measures to vary in a flexible manner over the growing season: Extreme heat is especially harmful around a third into the growing season. This is the time when the 2012 heat wave hit the Corn Belt. Our model predicts 2012 corn yields will be 23% below trend. While extreme heat was significantly above normal, climate change scenarios suggest that the 2012 outcomes will soon be the new normal.
Keywords: corn production; food price volatility; climate change
JEL Codes: Q11; Q5
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| Extreme heat (Q54) | Corn yields (Q13) |
| Degree days above 29°C (Q54) | Corn yields (Q13) |
| Extreme heat during specific phases (Q54) | Corn yields (Q13) |
| Climate change (Q54) | Extreme heat effects (Q54) |
| 2012 weather conditions (Q54) | Corn yields (Q13) |
| Allowing effect of extreme heat to vary (C22) | Corn yields (Q13) |