A Canadian looking for a high-end men's shoe from can buy it from a major online retailer in the U.S. or get it for 25 percent less at the bustling Eaton Centre mall in downtown Toronto.
But that price advantage could end, potentially devastating Canadian retailers, if the U.S. gets one of the major changes it seeks while it renegotiates the North American Free Trade Agreement with its two neighbors.
To protect its domestic companies, Canada currently imposes duties on any goods worth more than $16 in U.S. currency. Officials want to raise that duty-free limit to $800, vastly expanding the number of untaxed consumer goods flowing north.
It's a relatively...