Gains from the proposed United States-Mexico-Canada Agreement (USMCA) will be negated by even larger losses due to retaliatory tariffs applied by Canada and Mexico in response to higher steel and aluminum imports imposed by the United States, according to a trade analysis released last week by the Farm Foundation.

The study by Purdue University agricultural economists found the USMCA will lead to an expansion of U.S. agricultural exports by $450 million, mostly in the dairy and poultry sectors.

However, the analysis...