According to the Mortgage Bankers Association, Federal Housing Administration (FHA) mortgage delinquencies spiked in the fourth quarter for the first time since 2006. How does this affect FHA loans, which are a favorite for first-time home buyers? Wharton real estate professor Benjamin Keys and Mike Fratantoni, chief economist for the Mortgage Bankers Association, recently appeared on the Knowledge at Wharton show on Wharton Business Radio on SiriusXM channel 111 to discuss what is causing the increase in delinquencies and how it could impact the U.S. housing market.