http://www.businessinsider.com/housing-death-spiral-defaults-2010-10
Risk is so high in today’s real estate market that private money has largely left the mortgage category. The retreat is most easily seen in the jumbo mortgage market. Total jumbo mortgage origination has fallen from a high of $650 billion in 2003 to $92 billion in 2009 (see the chart above). Government loans account for 90% of current originations.

“If government policy does not change, over 11.5 million borrowers are in danger of losing their homes (1 borrower out of every 5),”‘ the report said, which estimates the total of homes with a first mortgage at 55 million. “Politically, this cannot happen.”
“The death spiral of lower home prices, more borrowers underwater, higher transition rates (to default), more distressed sales and lower home prices must be arrested.”