but if the economy does remain weak enough to cause a recession, it may end up being postdated back to March 2001, a senior San Francisco Federal Reserve Bank economist argues. So far, Glenn D. Rudebusch Senior Research Advisor writes in the San Francisco Fed's Economic Letter, the economy's weakness has not been sufficiently broad-based to confirm a recession, but "if a recession does occur, its start could well be dated to last spring." The data in hand do not confirm a recession thus far, though, says Rudebusch, who examines an array of statistics used by the National Bureau of Economic Research retrospectively in timing recessions.