U.S. Fed Chairman Ben S. Bernanke

U.S. Fed Chairman Ben S. Bernanke

Scott Eells/Bloomberg

Ben S. Bernanke, chairman of the U.S. Federal Reserve, has attracted plaudits and brickbats for his own action, which includes more than $2 trillion in emergency aid, three rounds of asset purchases, record-low interest rates and now thresholds for the reversal of stimulus.