Gramlich privately urged Fed examiners to investigate mortgage lenders affiliated with national banks, he was rebuffed by Alan Greenspan , the Fed chairman. As housing prices soared in what became a speculative bubble, Fed officials took comfort that foreclosure rates on subprime mortgages remained relatively low. The Center for Responsible Lending, a nonprofit group based in North Carolina, analyzed records from across the country and found that default rates on subprime loans soared to 20 percent in cities where home prices stopped rising or started to fall. The ethanol boom, they contend, is raising corn prices, driving up the cost of producing dairy products and meat, and causing farmers to plant so much corn as to crowd out other crops. In a study completed in May, researchers at Iowa State University concluded that retail food prices had already increased by $47 per person in the previous year or so as a result of higher corn prices. read more