How will the parties pay for their promises? Why costed platforms are important

As most of the major parties gear up to unveil their fully costed platforms, a former assistant parliamentary budget officer says they're important because Canadians want to understand how parties will implement their spending plans during a trade war.

"We really want to understand how they are addressing those really big issues and in a changing context," said Sahir Khan, now the executive vice-president of the Institute of Fiscal Studies and Democracy (IFSD) at the University of Ottawa.

Khan added the federal government is facing a worse budgetary outlook because of U.S. President Donald Trump's tariffs and the fact the Liberals' hike to capital gains did not become law before the campaign began.

"Everything's about $68 billion worse over the next five years," Khan said on CBC's The House, referencing an analysis from the IFSD about the federal deficit. "So a slower economy, more spending to cover EI and other supports for the industry."

"So we have got to figure out how these parties are going to demonstrate their fiscal plans, how they're going to implement and how they are — frankly — going to react," he told host Catherine Cullen.

On Friday afternoon, the Bloc Québécois became the first party to release a fully costed platform. However, because the Bloc only runs candidates in Quebec, it will never form government.

Earlier this week, the Green Party released a partially costed platform. The Parliamentary Budget Officer (PBO) has looked at some of the Green's proposals, including increasing the corporate income tax rate and raising the federal minimum wage.

At a campaign event in Niagara Falls, Ont., on Friday morning, Liberal Leader Mark Carney said his party's full platform will be unveiled on Saturday. 

NDP Leader Jagmeet Singh told reporters in Yamamiche, Que., on Friday morning that his party would release its full platform "very soon" and clarified it would be costed.

On Wednesday evening during the French leaders' debate, Conservative Leader Pierre Poilievre said his party will cost out its promises and the full platform "is going to come out in a few days."

Khan said the ISFD was caught by surprise when both the Liberals and Conservatives announced tax cuts. Carney has pledged to cut the tax rate of the lowest tax bracket by one percentage point. 

Poilievre wants to drop the tax rate on the lowest income tax bracket from 15 per cent to 12.75 per cent.

"Those two felt a little out of sorts given everything else that was going on," Khan said. "And I think we're really waiting to see how that fits in with all the other pieces. And this is a puzzle."

By the time the Liberals, Conservatives and NDP release their costed platforms, some Canadians will have already cast their ballots at advance polls.