Mere talk of tariffs will spur some consumers to run out and buy big-ticket items, or stockpile smaller ones, on the theory that prices will soon rise. That behavior, alone, could make prices increase . If Trump announces tariffs on his first day in office, as he has suggested, some prices could spike immediately.

President-elect Donald Trump on Monday promised massive hikes in tariffs on goods coming from Mexico, Canada and China starting on the first day of his administration, a policy that could sharply increase costs for American businesses and consumers.

The president-elect said that he would impose the across-the-board tariffs on Day 1 and that they would stay in place until Canada, Mexico and China halted the flow of drugs and migrants.