The Globe and Mail reports in its Friday edition that Donald Trump loves to talk about how much he loves tariffs. The Globe's Tony Keller writes that Mr. Trump has promised a tariff on all imports into the United States at 10 per cent, though at times he has suggested it might be 20 per cent, or higher. He has also talked about a 60-per-cent (or higher) tariff on all goods from China. Mr. Trump says a lot of stuff, and a lot of it makes little sense. This is the guy who called the North American free-trade agreement "the worst trade deal maybe ever signed anywhere," while calling its nearly indistinguishable replacement, the United States-Mexico-Canada Agreement, "the best and most important trade deal ever made." The only thing that is clear is that a tariff on Canadian exports to the U.S. would be bad for Canada. University of Calgary economist Trevor Tombe modelled a 10-per-cent Trump tariff and concluded it would result in a 0.88-per-cent reduction in Canadian incomes, and a 0.53-per-cent reduction in American incomes. Marc Ercolao, an economist at TD, believes that a 10-per-cent U.S. tariff, plus Canadian retaliation, would deliver a hit to Canada's gross domestic product of 2.4 per cent in the first two years.