Hello "Rational Ideas",

In a a small-population country like Canada, the ONLY WAY for house prices in a city to reach dozens of times the average annual local income...

... is through a massive arriving flood of money from an external source.

THAT is the ONLY mechanism that can mathematically and economically explain the noted house prices, dozens of times the average annual local income. There is NO other way to get there. 

In the case of Vancouver, that external source was mainly money from Hong Kong and China. 

As for Toronto? Well, a research article posted by Dorah elsewhere on today's board stated this:

"This paper shows that the primary determinants of Toronto’s high housing prices lie on the demand side, and that the element of foreign investment has been under-appreciated by various public authorities to this point. The case for supply-side reform is overstated and would not address the immediate challenges facing the city."