The Globe and Mail reports in its Thursday edition that the Prime Minister and Canada's premiers left a meeting Wednesday promising to come up with "retaliatory measures" to respond to U.S. president-elect Donald Trump's threatened tariffs, but they have yet to say what exactly those actions would include. The Globe's Jeff Gray writes that Canada could also choose to respond to tariffs in kind and immediately slap a 25-per-cent levy on all U.S. imports but critics of this approach warn it would multiply the Canadian pain caused by the initial U.S. tariffs. Dennis Darby at the Canadian Manufacturers and Exporters said Canada should follow the path it took in Mr. Trump's first term when the country imposed targeted retaliatory tariffs to counter U.S. ones on steel and aluminum. He said Canada excluded inputs, such as parts destined for Canadian factories, in order to avoid doing even more harm to domestic industries. An analysis released last year by Bank of Nova Scotia chief economist Jean-François Perrault estimated that 25-per-cent tariffs on Canada's U.S. exports, combined with matching tariffs imposed by Ottawa on American products, could gouge a whopping 5.6 per cent off Canada's gross domestic product.