Interesting that unlike the vast difference between the U.S. 10 and 20 city composite graphs the Canadian 6 and 11 are essentially the same. This might be evidence that the bubble in Canada is more widespread than in the U.S. Remember those insane Vancouver #s are a larger percent of the Composite 6, yet despite that it hasn't caused that line to pull away from the Composite 11.
According to the 2011 Demographia Survey, Montreal is the second most expensive city in Canada relative to incomes. That's also a bigger component in the Composite 6. The Teranet numbers are all about gains in prices, not absolutes. Unsustainable gains are what forms a bubble.
Why isn't there more variation between the Composite 6 and 11?
Here are the 6 cities with their weightings
Vancouver: 23.3% Calgary: 9.9% Toronto: 41.4% Ottawa-Gatineau: 6.8% Montréal: 16.8% Halifax: 1.8%%
And the 11 cities with their weightings
Victoria: 3.2% Vancouver: 19.5% Calgary: 8.3% Edmonton: 5.2% Winnipeg: 2.2% Hamilton: 3.7% Toronto: 34.6% Ottawa-Gatineau: 5.7% Montréal: 14% Québec: 2.1% Halifax: 1.5%
The additional 5 cities have a combined weighting of 16.4% in the Composite 11. One might argue it is too small to tweak the graph, but why are these additional five cities tweaking the line *upwards* if this bubble is confined to only Vancouver and Toronto?