Housing prices are down 24% in real terms from their height, with 10 million people under water. That is already a castrophe, but it is probably going to get much worse, says Robert Shiller. As to real estate myths, in real terms, housing prices in the US were about the same in 1990 as in 1890. Your home, a depreciating good, is NOT an investment. (Thanks to Steve Bartin.)