Yale housing guru Robert Shiller says he’s still not convinced the housing recovery is real. Shiller tells CNBC that some 10 million homeowners are still underwater on their mortgages, and many will end up in foreclosure. Those foreclosures will add inventory to the housing market, he says, and economic risks at home and abroad are also a concern. “I still think it’s a risky market,” he says. Shiller also says that the potential elimination or reduction of the mortgage deduction as part of fiscal cliff negotiations could lead to a big shift from buying homes to renting homes.