GAO examined five of the nine qualified mortgage criteria specified in the DoddFrank Act for which sufficient data were available and generally found that, for 

each year from 2001 through 2010, most mortgages would likely have met the 

individual criteria. The five criteria address payment of loan principal, length of 

the mortgage term, scheduled lump-sum payments, documentation of borrower 

resources, and borrower debt burden. 

The impact of the full set of qualified mortgage criteria is uncertain, partly because data limitations make analysis of the other four criteria difficult and partly because federal agencies could establish different criteria as they develop final regulations. Consumer and industry groups indicated that the criteria specified in the act would likely encourage sound underwriting but could also restrict the availability of and raise the cost of 

mortgage credit for some homebuyers. 

The full report can be accessed here