By John S. McClenahen Even as U.S. President George W. Bush goes about assembling a new economic team for his second term, Washington, D.C. is abuzz about an upcoming and arguably more important selection: a successor to Federal Reserve Chairman Alan Greenspan. Unless events alter the timetable, by this time next year Bush will have named the next Fed head. Speculation now is focused on Martin S. Feldstein, an economics professor at Harvard University and president of the National Bureau of Economic Research, and R. Glenn Hubbard, a professor of economics and finance at Columbia University and a former chairman of the President's Council of Economic Advisers. Under current law, Greenspan is slated to leave the Fed on Jan. 31, 2006. His successor must be confirmed by the Senate. "In selecting a candidate, the president will undoubtedly look for someone who will command respect in financial markets. But he is also likely to seek someone who, ideologically at least, will support the president's proposals on issues as tax reform and Social Security privatization," says James O'Sullivan, a senior economist at UBS Securities LLC.