Not just subsidized mortgages. Also tax and other incentives, zoning laws that make it more difficult to build rental properties, and infrastructure that can't support (or is specifically designed to prevent) the kind of population density it takes for building rental properties make financial sense for developers in many areas.
Combined with a lot of political tailwind behind these kinds of broad-spectrum public subsidies of landowners, because in the USA it's common for working class folks to think of themselves as really just being rich people who happen to not have a whole lot of money.
I like the quote, "Socialism never took root in America because the poor see themselves not as an exploited proletariat, but as temporarily embarrassed millionaires." often attributed to Steinbeck.
Exactly. This is most certainly not cyclic because legislation and incentives are not cyclic in nature. If laws, regulations, contracts, policies, etc. don't change, then this is likely to get worse before it gets better.
More than that, the US mortgage market has essentially been nationalized: Over 95% of mortgages are backed by Fannie Mae and Freddie Mac (which in turn are backed by the federal gov). Nowhere else in the world can homebuyers get a fixed 30 year mortgage at 4.17% (http://www.freddiemac.com/).
