Chairman Ben Bernanke moved the Federal Reserve further into uncharted policy territory in combating joblessness by tying the bank's interest-rate outlook to unemployment and inflation, while committing to an even faster expansion of the central bank's balance sheet.
The actions on the eve of the Fed's centenary year underscore Bernanke's hallmark commitment to experimentation and forceful action, derived in part from his research showing too little monetary stimulus produced large economic costs for the US in the 1930s and for Japan in the 1990s.

Source - http://economictimes.indiatimes.com