The Globe and Mail reports in its Saturday edition that U.S. tariffs of 15 per cent on Canadian-made vehicles would erode automakers' profitability and spur the domestic industry's decline. The Globe's Eric Atkins writes that during negotiations on autos, the U.S. offered to reduce its tariffs on Canadian-made cars to 15 per cent from 25 per cent. The tariff would exclude U.S. content, but the two sides were haggling over whether Canadian and Mexican content would also be excluded. Automotive experts say that a tariff of 15 per cent excluding only U.S. content would prod carmakers in Canada to slow or halt plant upgrades and look elsewhere to build new models in countries where they can turn a profit. The U.S. content in a car assembled in Canada varies but is about 50 per cent on average. This would mean an effective tariff rate of 6 to 8 per cent, which is roughly equal to the labour costs of assembly and, separately, the margin of profit on a vehicle. Peter Frise at the University of Windsor said, "In an industry where profit margins are typically 6 to 8 per cent, 15 per cent is a lot." The U.S. has also applied 15-per-cent tariffs on most foreign imports. The tariffs have cost U.S. carmakers billions of dollars.