[Sylvanfan]

The problem with the US method of writing off mortgage interest is that most people don't keep using their home equity to get cheap money to invest and grow their wealth. They keep using it to buy Hummers and bling.

As conservative as our system is, it does tend to force people to be a bit more money savvy if they want to try something like the Smith maneuvre to write of mortgage interest. Generally people who will do smarter things with the money if they figure this out because the average person has no idea that these options exist. So the average person with a mortage is forced into saving a few dollars and building home equity rather than constantly re-financing their home so they can continue with an excess life style for another 5 years.