Now nearing the last year in his third term as head of the seven-member board of governors of the Federal Reserve System, Alan Greenspan has frequently been called the most powerful person in the nation, second only to the president.

The claim is not without some validity. As chairman of the Federal Reserve, Greenspan guides the nation--and by extension the world's--monetary policy, adjusting interest rates which change the cost of borrowing money.

He has been credited with engineering, or at least preserving, the current American economic expansion. Markets tremble and plunge at a mere phrase from him.

And in addition to his economic wizardry, he is a social butterfly with a quick, if dry, wit and a decent tennis backhand. Behind the chief's desk in the whisper-quiet halls of the Fed sits Alan Greenspan.

The buck starts here.

The Money Man

Because money managers across the globe, as well as everyone on Wall Street, pay such close attention to his words, trying desperately to parse them for indications of future policy moves, Greenspan guards his words carefully. He is notoriously stingy with full on-the-record interviews to the media.

In December 1996 with the stock market soaring to record highs, Greenspan spoke at a Washington dinner party, wondering aloud if the flow of money into the stock market was simply "irrational exuberance."

The next day, fearing that his comment was a harbinger of a forthcoming increase in interest rates, the Dow Jones industrial average fell 140 points.

The speculation was wrong, and the interest rates remained unchanged.

Greenspan, who will give the keynote address at today's Commencement, will likely not speak in obscure terms to the graduates, but Harvard's Class of 1999, should not expect investment tips either.

"I don't know what he will talk about, but I expect it will be about the economy and monetary policy generally, rather than making a policy announcement here," Baker Professor of Economics Martin S. Feldstein '61 wrote in an e-mail message.

Feldstein will serve as Greenspan's faculty escort during the Commencement activities, a duty he says the University selected him to perform because of their mutual interest in economic policy.

Feldstein, who like Greenspan was appointed to high office by President Ronald Reagan, counts himself among the legions of people who think highly of Greenspan's economic handiwork.

"I think his policies have been very good," Feldstein wrote in his e-mail message. "He dealt wisely with bringing down inflation, he responded well to two financial market crises (the 1987 stock market crash and the 1998 credit crunch), and he has helped to advance important improvements in deregulating the financial sector."