Insofar as cash and futures markets for grain and the soy complex are concerned, the impacts of U.S. trade policy issues are ultimately measured by the volumes of export sales and shipments. The fact that such issues currently involve China, Mexico and Canada ensures that whatever happens in the bigger picture will almost certainly affect the relationship between prices for U.S. corn, wheat, soybeans/soy products and those for competing origins. The perversion of trade disputes is that they can change trade flows in ways that disregard comparative price advantage. This can already be seen in the small volume of U.S. soybeans recently sold to China despite their substantial discount to Brazilian prices. Indirectly, it has also led to an appa...