U.S. Federal Reserve chair Yellen speaks to the Economic Club of New York in New York

U.S. Federal Reserve chair Janet Yellen speaks to the Economic Club of New York in New York April 16, 2014. Yellen said on Wednesday the U.S. economy appeared to be slowly moving toward full employment, but that it would need help from the central bank for some time to come. REUTERS/Brendan McDermid (UNITED STATES – Tags: POLITICS BUSINESS)