Economists and central bankers gathering this past weekend at the American Economists Association found reasons to be optimistic. The U.S. economy is slowing but odds of a recession are low. Low interest rates and a solid jobs market offset a slowdown in manufacturing. The IMF predicts global economic growth to increase in 2020 and again in 2021, leg by improvements in many emerging markets. In reaction to the growth, raw material prices have been rising and the dollar is at its lowest level since March, a factor that further boosts commodity consumption. GDP growth is much more volatile than major agricultural commodity ending stocks, but there is nonetheless a correlation. GDP growth spurs consumption. If geopolitical volatility does not...