In 2008, half of all mortgages were high risk

See Follow the Weak Mortgages by Peter J. Wallison. He is a senior fellow at AEI and a member of the Financial Crisis Inquiry Commission.

"In my dissent, I point out that before the financial crisis began in 2008, half of all mortgages in the U.S. financial system -- 27 million loans -- were subprime or otherwise high risk. This was an unprecedented number and a far larger percentage than in any bubble in the past.

Why were so many U.S. mortgages so weak? Both the Democratic and Republican reports ignored this central question. The answer is that it was Housing and Urban Development's policy, from 1992 to 2007, to reduce mortgage underwriting standards so that more people could buy homes. Home ownership rates rose. But in 2007 it all came apart."