American consumers paid $5.92 billion more than necessary for softwood lumber, according to a Viewpoint published today by the Montreal Economic Institute (MEI).

In a press release announcing the Viewpoint, MEI says that because of the softwood lumber agreement of 2006 “tariffs at the border have reduced Canadian exports and [allowed] American producers to increase their market shares. The latter thus registered additional net earnings of US$4.31 billion between 2006 and 2015.”

The Viewpoint’s author, Alexandre Moreau, says in the press release that American consumers overpaid for lumber because of the U.S.’ “protectionist measures,” and that consumers would not have paid the additional $6 billion if the U.S. government had engaged in free trade with Canada.

Both Canada and U.S. officials have engaged in discussions for months about drafting a new softwood lumber agreement. The nations have until Oct. 12 to create a new agreement. After that date, both nations are allowed to launch trade disputes.