China has been purchasing significant volumes of corn at the same time it sits on the majority of the world’s surplus carryover of the grain. Its policy adjustment in recent years has brought its share of the global carryover down slightly but it still measures 61 percent. By contrast, the U.S. share of the surplus has risen from 16.5 percent to 22 percent of global corn stocks.  China could be buying to fulfill its Phase One trade agreement commitments, or it could have smaller or more damaged corn stocks than publicly advertised. U.S. policy officials have told China that U.S. surplus stock building was a mistake in the 1980’s and they should learn from America’s painful experience. Yet, Washington looks to be repe...