Understood, and makes sense. But even variable rate mortgages in US do not require maintaining equity threshold, do they? Maybe also consequence of govt guarantee. Though I wonder what Canadian central bank would do if it finds itself in the same situation of mass mortgage defaults/underwater mortgages as happened in US - I suspect they would also opt for one or another form of bailout, thus implementing implied, if not explicit, guarantee.

Tax breaks of course is another thing that massively influences US mortgages. I probably would never take my current mortgage if not the interest tax break.