How Widespread are Subprime Problems?

Pretty far. From the WSJ (subscription required):

Far from being limited to the subprime market, the data show these risky loan features have become widespread. According to Credit Suisse, the number of no or low documentation loans -- so-called "liar loans" -- has increased to 49% last year from 18% of purchase loans in 2001, a nearly three-fold increase. The investment bank also found that borrowers put up less than a 5% down payment in 46% of all home purchases last year. Inside Mortgage Finance estimates that nontraditional mortgages -- mostly interest-only and pay-option ARMs that allow the borrower to defer paying back principal or even increase the loan balance each month -- which barely existed five years ago, grew to close to a third of all mortgages last year.

The Alt-A market, a middle ground between subprime and prime, has increased seven-fold since 2001 and accounted for 20% of home-purchase loans last year. Fully 81% of Alt-A loans last year were no or low documentation loans, according to First American Loan Performance. Why have borrowers employed this kind of risky financing? Because it was the only way many of them could afford a home in some of the hottest housing markets, where prices more than doubled in five years.