Dollar parity between the U.S. and Canada and duty on clothes

This story from Tyler Cowen at Marginal Revolution. Tyler writes,

Canadian shoppers taking advantage of the parity between the U.S. and Canadian dollars are leaving behind more than cash when the head home.

They're leaving behind their old clothes.

Some Canadian shoppers wear their new clothes home to avoid paying a duty when they cross back into Canada. The old clothes get left behind in parking lots, dressing rooms and restrooms at malls and shopping plazas in the Buffalo-Niagara Falls region.

At the Fashion Outlets mall just outside the city of Niagara Falls, managers have placed collection bins near the exits where Canadians customers can deposit their unwanted items.