Forecasts for the Federal Reserve to scale back its assets purchases are shifting rapidly. USA Today reports seven of 10 economists now foresee the central bank easing off the pedal this year, and most think it will happen by early fall.

Last week's survey reveals a dramatic shift in economists' outlook, said USA Today. In May, most economists thought the Fed would maintain the current pace of purchases until next year.

The change in economists' expectations is in tune with a similar shift occurring in financial markets, where volatility has increased significantly in recent weeks. Fears have been stoked by comments from various Fed members, and a statement from Chairman Ben Bernanke really aggravated the concerns.

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"In the next few meetings, we could take a step down in our pace of purchase," Bernanke told the Joint Economic Committee last month.

He said there has been "some improvement" in the job market and that central bankers will focus on whether this continues. "There is confidence that it is going to be sustained," MarketWatch quoted Bernanke as telling the committee.

That job growth has averaged 190,000 per month is contributing to expectations for a pullback. And anticipation is running high about what will come out of this week's meeting of the Fed's policy-making Federal Open Market Committee.

Michael Feroli, a JP Morgan economist, thinks Bernanke "will likely choose his words a little more carefully." He will probably stress that bond purchases could be reduced but then increased again if the economy falters, Feroli told USA Today.

Dan Greenhaus, chief global strategist at BTIG LLC told MarketWatch that he also believes the Fed pullback will begin around September, but he isn't worried. "I think people are freaking out about nothing," he said.

"Tapering" is simply another word for reducing, he explained to MarketWatch. The Fed is currently purchasing $85 billion per month in assets and if that was reduced to, say, $75 billion, Greenhaus said the move would be irrelevant for investors. It's not like the Fed will pull out altogether, he says.

But the tapering of asset purchases isn't investors' only concern. They are also worried that the Fed will raise interest rates sooner than expected.

Bernanke has repeatedly said the Fed's current interest-rate policy will remain intact until unemployment falls to 6.5 percent. But short- and long-term rates have risen, and USA Today says despite the chairman's reiterations, Fed-funds futures contracts show the markets are expecting the central bank to act sooner.

Greenhaus told MarketWatch that the Fed needs to use this week's meeting to make it clear that asset purchases and interest rate policy are separate issues.

In any case, the policy is not a cause for the degree of concern it's generating, he says.

“The decision to raise interest rates shouldn’t have anything to do with whether the stock market stamps its feet or not,” Greenhaus told MarketWatch.

But it has, and USA Today says Bernanke is expected to offer reassurance that a reduction in stimulus will not lead to an unexpected rise in interest rates.

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