Risk in the mortgage market may be severely understated, according to new research that calls into question the ability of rating agencies to assess the dangers of collateralized debt obligations backed by mortgages and communicate them to investors.A paper presented at the Hudson Institute, a nonpartisan public policy research organization based in Washington, found that such CDOs could experience significant losses if the U.S. housing market continues to stagnate. "We don't want to shut down" mortgage-backed securities, said one of the study's authors, Joseph Mason of the LeBow School of Business at Drexel University. "We're only looking for greater transparency to foster stability." As it is now, Mr. Mason said, rating agencies "can't look under the hood of these deals unless they are qualified investors." But Michael Fratantoni, senior director of single-family research and economics at the Mortgage Bankers Association, played down the research, saying that while CDOs are complicated, they should not be looked at in isolation. "Complexity is in the eye of the beholder," the MBA economist said. "There is no lack of information." However, Mr. Mason warned that the rise in private-label CDOs that are not backed by the government is a potential threat to the economy if home prices depreciate. "It won't start a recession," he said. "But if we get into an economic downturn, it could widen."
