No one knows what will happen, but it's not hard to argue that the housing market is nearing a bottom. Home construction is as unsustainably low today as it was unsustainably high during the bubble. The more builders like KB Homes (NYSE: KBH) and Lennar (NYSE: LEN) are beaten into submission today, the bigger the housing rebound will eventually become.

That's the good news. But here's a question few are asking: After the housing market does bottom, what you should expect from it going forward?

I asked Yale economist Robert Shiller -- of S&P/Case-Shiller housing index fame -- that question in an exclusive interview earlier this month. His answer might shock you: Not only do home prices, on average, not produce real returns over time, but history shows they could actually decline over the long haul. Have a look: