Canadian Prime Minister Justin Trudeau, responding to protests over a mandate that truckers crossing the border be vaccinated against COVID, says that the requirement has not slowed trade. Indeed, that is true. In fact, the growth in cross-border trade in food over-shot trend in 2021 and is up 17-18 percent during the first two months of this fiscal year.  The largest increase, over $9 billion, was in U.S. imports of Canadian forest products. The surge responds to a rapid increase in U.S. home building in the face of housing shortages. The growth in agricultural products moving northbound has been more modest, with recent increases in grain and grain products like DDG’s reflecting the shortfall in Canadian production due to drou...