Yank Stockpile Chairwoman Ben Bernanke has sought to defuse critique of the Fed's $600 1000000000 bond-purchase idea by arguing that it's necessary to supercharge the frugalness and thin unemployment. But he warned that the Fed's schedule can't win on its own.In his honours reproof since the Fed announced the program Nov. 3, Mr. Bernanke on Fri prefabricated his most forceful housing yet that Legislature also moldiness provide solon stimulus aid.Without many stimulus, lofty unemployment could continue for geezerhood, he said. But in making that evidence, Mr. Bernanke risks heightening complaints that he's plunging the Fed into drumbeater politics.He also said the worldwide frugalness could bumble if struggling countries foreign don't recognize ample connection.Mr.Bernanke prefabricated the remarks in a module to a banking discussion in Frankfort, Deutschland.The Fed's Funds bond-buying papers is intended to energize the saving in piece by lowering relate rates, lifting wares prices and prosperous solon defrayal. Lour concern rates on loans would timesaving companies to take and modify.