If a recession is headed our way, the canaries in the economic coal mine that are most likely to sing its arrival will be Canada's big banks. That's because Canada's five biggest lenders — Royal Bank, TD, Bank of Montreal, Scotiabank and CIBC — have a hand in nearly every aspect of Canada's economy, from loaning businesses money for expansion to funding the mortgages that finance much of the housing market.

Those same banks are in the midst of revealing their quarterly earnings this week, and the numbers should offer a good glimpse of where the economy is headed.

Profits up

The Royal Bank of Canada was first to report last week, showing profits rising to a record $3.3 billion in the third quarter. CIBC was next, with a quarterly profit of $1.4 billion in the three months up to the end of July.

Both figures are up only slightly from last year's level, but in a world in which the financial media is warning of negative rates, inverted yields...