Despite gloomy and even fear-provoking headlines describing the U.S. economy these days, Federal Reserve Chairman Ben Bernanke has been rather quiet on whether the U.S. central bank will jolt the economy with stimulus measures.

That silence speaks volumes, says Mohamed El-Erian, CEO of Pimco, manager of the world's largest bond fund.

While acknowledging that headwinds face the U.S. economy, the Federal Reserve cannot rely on policy tools such as quantitative easing — bond buybacks from banks — like it has in the past unless the economy seriously deteriorates.

Editor's Note: You Deserve to Know What Obama and Bernanke Are Hiding From Americans

Since the downturn, the Fed has snapped up $2.3 trillion in mortgage-backed securities and Treasurys held by banks with the aim of injecting liquidity into the economy and pushing down interest rates to speed up recovery and encourage hiring.

Easing measures prop up stock prices with the aim of encouraging more investment and hiring, and poor jobs reports and sluggish growth rates in the U.S. have sparked calls for more Fed intervention.

Still, Bernanke remains somewhat vague on that issue when speaking in public, pointing out that easing remains a tool that can be used, but only if needed.

In other words, it's up to Congress to act now.

"Bernanke is trying hard to shift the focus from monetary policy to other areas (particularly fiscal). This speaks to his lack of specificity on future monetary policy actions and to his comment that he would feel much more comfortable if Congress were to take some of the policy burden off the Fed," El-Erian writes in a CNBC guest blog.

"This is all consistent with the growing view in both academic and policy circles that unusual central bank activism is becoming less effective overall."

European Central Bank President Mario Draghi has taken a similar tone, voicing the bank will act if needed but stops short of saying if the European monetary policy authority will renew its accommodative policy tool of choice — long-term refinancing operations, which are low-cost loans made available to banks designed to ease credit conditions in Europe.

"Central bankers are becoming more nuanced and thus differentiating between the trio of policy willingness, ability and effectiveness," El-Erian says.

"They are telling us that they are willing to do more if conditions deteriorate; the ability is there though impacted by imperfect policy instruments; and effectiveness is not what it used to be."

Fiscal reforms are needed now in the U.S., though such changes are often harder to push through due to political bickering between Democrats and Republicans in Congress and then among both parties and the White House.

The Federal Reserve operates independently and often behind closed doors.
Furthermore, fiscal issues often deal with tax and spending policies, which can get politically sensitive in an election year.

Such sensitive issues will take center stage at the end of this year, just after the November elections.

Tax cuts are set to expire, while automatic spending cuts are set to kick in, and the combination of such — dubbed by Wall Street as the fiscal cliff — could siphon hundreds of billions out of the economy next year and possibly send the U.S. tumbling right back into recession.

Bernanke told lawmakers to do what they can to avoid it.

"The so-called fiscal cliff would, if allowed to occur, pose a significant threat to the recovery," Bernanke told Congress, according to the AFP newswire..

The European debt crisis is threatening to derail recovery as well, Bernanke warns.

"The situation in Europe poses significant risks to the US financial system and economy and must be monitored closely."

Editor's Note: You Deserve to Know What Obama and Bernanke Are Hiding From Americans