US Federal Reserve Chairman Mr Alan Greenspan says policymakers have been proven correct in their decision not to try to prick a 1990s stock-market bubble that subsequently broke on its own.

"There appears to be enough evidence, at least tentatively, to conclude that our strategy of addressing the bubble's consequences rather than the bubble itself has been successful," Mr Greenspan told the annual meeting of the American Economic Association in San Diego, California, at the weekend.

Mr Greenspan cited the "exceptionally" mild nature of the eight-month 2001 recession despite a series of shocks to the economy that included plunging stock prices, the September 11th attacks, corporate scandals and wars in Afghanistan and Iraq.

In defending the Fed's tactics, Mr Greenspan said had Fed stepped in to curb stock prices by raising rates, it might have done damage to the entire economy in the process. Stock prices collapsed in early 2000, wiping out trillions of dollars of investors' wealth.

Now in his 17th year as chief of the US central bank, Mr Greenspan stressed that sound policymaking requires judgment and can be helped, but not fully guided, through simple rules.

He said the US economy's resilience and ability to adapt quickly had also increased its ability to weather adversity.

"Much of the ability of the US economy to absorb these sequences of shocks resulted from notably improved structural flexibility," Mr Greenspan said in a relatively academic address.

"But highly aggressive monetary ease was doubtless also a significant contributor to stability."

He said the idea that the Fed could have brought the 1990s stock bubble to a gentle decline by ratcheting up interest rates - as some critics have suggested it should have done - "is almost surely an illusion".

In a question-and-answer period later, Mr Greenspan said policymakers could have halted the rise in stock prices by raising interest rates until it happened, "but it would bring the whole economy down with it".

The Fed chief made no comment about current US economic conditions and offered no hint about how soon US central bank policymakers might move interest rates up from 45-year lows in the face of mounting evidence of a broad-based recovery in US economic activity.

Mr Greenspan said policymakers had to choose between a variety of possible events in setting a course for interest rates.

"A central bank needs to consider not only the most likely future path for the economy but also the distribution of possible outcomes about that path," he said.

He said such judgment was a factor in the Fed's decision to take a low interest-rates stance to limit the risk of deflation, a potentially dangerous fall in consumer prices, even though such an outcome did not appear to be in the cards.

"Such a cost-benefit analysis is an ongoing part of monetary policy decision-making and causes us to tip more toward monetary ease when a contractionary event ... seems especially likely or the costs associated with it seem especially high," he said.

The Fed lowered interest rates by 4¾ percentage points in 2001 after the stock market's collapse and the September 11th attacks, and by another three-quarters of a percentage point by the end of June 2003 to the current 1 per cent, the lowest rate since 1958.

In a reference to inflation-targeting regimes used by some other countries' central banks, including the European Central Bank, though not the Federal Reserve, Mr Greenspan suggested they could not replace a solid record of sound policy guided by judgment.   - (Reuters)