Richard Portes, president and founder of the influential London-based Centre for Economic Policy Research, and three other heavyweight economists have a way to avoid future credit crises like the current subprime-derived mess. In “International Financial Stability,” a 190-page paper published in November by CEPR and another prominent think tank, Geneva’s International Center for Monetary and Banking Studies, Portes and his co-authors — Philipp Hartmann, head of research at the European Central Bank; Roger Ferguson, former vice chairman of the U.S. Federal Reserve Board and current chairman of Swiss Re America; and Fabio Panetta, a senior researcher at the Bank of Italy — say that banks should keep a portion of all the loans they make, rather than sell them off to third parties through securitizations. “Exactly how much they retain is a question regulators need to study, but it should be enough to make banks feel pain in the event of default,” says Portes. “That will lead to more screening of borrowers, which will help avoid crises like subprime.”