A recent real estate conference I attended had a speaker talking about whether or not housing really was an amazing investment that was always going to produce amazing returns, or if the increases in home values over the years was due to changes in lending that made it easier for consumers to borrow more money.
This graph supports his feelings, look particularly at the post WW-II increase, when the GI Bill made home purchasing dramatically easier for a large number of Americans. The next big spike is the 1970′s, when Freddie and Fannie were created and began the securitization of mortgages, allowing them to be resold on secondary markets. And then you have the 1980′s, which introduced the adjustable rate mortgage. And finally, the 2000′s, when sub-prime and a variety of other “exotic” mortgages were introduced.