It might be more than a little disrespectful to call Alan Greenspan a sock puppet, but that’s one role he seems to be playing these days. Not that Federal Reserve Chairman Ben S. Bernanke can’t speak for himself. He does, and fairly clearly. But Greenspan — by design or not — may be saying things that Bernanke wishes he could.

Since Greenspan began roiling financial markets three weeks ago with both private and public statements that the chance of a U.S. recession is rising, numerous commentators have said he has no business stepping on Bernanke’s lines. The suggestion is that the 81-year-old Greenspan can’t stand that he’s no longer the world’s pre-eminent economic prognosticator.

But after 18 mostly well-regarded years at the helm of the U.S. central bank, Greenspan and his words carry a degree of weight that Bernanke, with 14 months on the job, can only hope for at this point. If a message needs to be delivered to investors and regulators and policy makers that there are problems in the mortgage market or with imbalances in the U.S. economy, why not allow someone else to play messenger?

Greenspan himself might have wished he’d had such an alter ego when he attempted on several occasions in the late 1990s to stop an unjustified and ultimately disastrous rise in stock prices.

The Dow Jones industrial average stood at 6,437 on Dec. 5, 1996. That evening, in an otherwise uneventful Washington speech, Greenspan openly fretted for the first time that U.S. shares were overvalued. Asian stock markets plunged, and the next day the Dow dropped 55 points, a bit less than 1 percent. After a few more ups and downs in the ensuing weeks, the Dow ended the year ahead of where it had been before Greenspan’s remarks.

Then, in September 1998, in a somewhat more blunt speech at the University of California, Berkeley, Greenspan again tried to raise doubts about the still-building Internet boom. His comments came in the midst of an international currency crisis — and stocks, which were already skidding, fell that day. Still, by the end of the year, the Dow had climbed above 9,000 for the first time and was settled in for a steady rise to almost 12,000 before the market succumbed.

Part of Greenspan’s problem was the way he phrased his concern. His now-famous 1996 warning was posed in the form of a convoluted question: “How do we know when irrational exuberance has unduly escalated asset values, which then become subject to unexpected and prolonged contractions?” His 1998 follow-up was no less oblique. “The way we evaluate assets, and the way changes in those values affect our economy, do not appear to be coming out of a set of rules that is different from the one that governed the actions of our forebears,” he said. “Hence, as the first cut at the question ‘Is there a new economy?’ the answer in a more profound sense is ‘No.’ ”

It’s hardly a wonder that investors weren’t convinced that the Maestro was conducting a dirge for the dot-coms of the world.

Part of the problem confronting Bernanke is that anything from the mouth of the Fed chairman gets exaggerated. So, although he has already won plaudits for being more plain-spoken than his predecessor, he still must choose his words carefully.

At the end of February, after the Dow had its largest one-day drop in four years, Bernanke used a Capitol Hill appearance to reassure investors that subprime loan defaults were “a concern, but at this point we don’t see it as being a broad financial concern or a major factor in assessing the course of the economy.”

That was mostly before Greenspan began spouting off, and Bernanke has said little on the subject since.

The fact is, Bernanke may be chairman of the U.S. central bank, but he shares the job of setting monetary policy with his colleagues on the seven-member Fed Board of Governors and the presidents of 12 regional Fed banks. Bernanke seems to favor transparency, and if that’s the case, he’ll have to put up with contradictory voices. One of those bank presidents, Jeffrey M. Lacker of Richmond, dissented four times last year when the Fed held interest rates steady. Lacker wanted a rate increase to tamp inflation, which he fears threatens to accelerate — a position sharply at odds with Bernanke’s. Another bank president, Charles I. Plosser of Philadelphia, this month prodded the Fed to be more clear about its commitment to specific inflation objectives, also putting Bernanke on the spot.

Others in Bernanke’s circle are banging the cymbals about threats to the economy a bit more loudly than they had been. Fed Governor Susan Schmidt Bies, a former bank risk manager, told an audience a month ago that the central bank wasn’t much worried about subprime mortgage defaults and foreclosures affecting broader financial markets. By mid-March, she was fretting that “this is not the end, this is the beginning” of a wave of subprime failures, though the Fed still sees no “contagion” among ordinary lenders.

Greenspan says it may happen, though.

For now, Bernanke is keeping his counsel, and if he’s annoyed at the attention Greenspan’s getting — or at his message that things aren’t entirely rosy — he hasn’t even hinted at that. If, at some point, Bernanke has bad news to deliver, he might be glad that Greenspan — or someone — has softened up the audience.