The Three Gorges Dam on the Yangtze River is the world’s largest and most controversial hydropower project. The 600 kilometer-long reservoir has displaced 1.3 million people and is wreaking havoc with the environment. The reservoir reached its final height in 2010, but many of its impacts...

In the long view, recent volatility of prices of the major grains is not anomalous. Wheat, rice, and maize are highly substitutable in the global market for calories, and when aggregate stocks decline to minimal feasible levels, prices become highly sensitive to small shocks, consistent with the...