(131009) -- WASHINGTON D.C., Oct. 9, 2013 (Xinhua) -- U.S. President Barack Obama listen as Janet Yellen (R), the current Federal Reserve Vice Chairwoman, speaks in the State Dining Room of the White House in Washington D.C., Oct. 9, 2013. Obama on Wednesday formally nominated current Federal Reserve Vice Chairwoman Janet Yellen to be the next Fed chief. (Xinhua/Zhang Jun)