Federal Reserve Chairman Ben S. Bernanke

Federal Reserve Chairman Ben S. Bernanke

Scott Eells/Bloomberg

Ben S. Bernanke, chairman of the U.S. Federal Reserve, is seen here in a Nov. 20, 2012 photo. While the Fed may have positioned itself to more easily halt its stimulus if the economy picks up, its base-case scenario may prove too rosy, along with the even more optimistic outlook.