With the Federal Reserve having doubled its base of assets to $2.1 trillion in the past month, Philadelphia Fed Bank President Charles Plosser yesterday urged that the system consider how it can gracefully retrench once the economic crisis ebbs.

Mr. Plosser told an Economics Club of Pittsburgh luncheon that he supported the bailout moves aimed at easing credit, boosting liquidity and rescuing select institutions that pose, to borrow Chairman Ben Bernanke's phrase, "systemic risk."

But in addressing the crowd of some 200 at the Omni William Penn Hotel, Downtown, he spoke of his overarching concern that the Fed look toward devising a more precise, trigger point-based decision process.

"This expansion of the scope and scale of Fed lending may not have been so large," he said, "had we had better resolution mechanisms to deal with such failing firms as Bear Stearns and AIG."

Without tipping his hand on what he'll do Dec. 16, Mr. Plosser, one of 10 voting Federal Open Market Committee members, said cutting the Fed rate below its current 1 percent would pose a raft of complications.

"I don't know what it'll take, but the closer one gets to zero, the technical consequences become difficult," he said. "What are you going to do when money markets charge fees and offer zero percent?"

Mr. Plosser's economic forecast was for gross domestic product to show negative growth in the fourth quarter as it had in the third, before inching upward. As for the unemployment rate, he foresaw a climb well above 7 percent in 2009 before a midyear retreat.

While recent decisions have been unanimous, Mr. Plosser had been one of two Federal Open Market Committee members who in March opposed a 75-basis-point cut to 2 1/4 percent.

Subsequent drops in energy and commodity prices have eased his concerns of stirring an overheated economy, but not those related to the burst of new programs that the Fed has taken on this past month.

Mr. Plosser said the Fed discount loan window, for instance, used to be reserved for banks, credit unions and savings and loans.

In the past year or so, he said, the preferred loans have been made to securities dealers, investment banks, a global insurer and most recently to issuers of commercial paper.

"This panoply of lending facilities bears little resemblance to the classic textbook image of the Fed's discount window in normal times. It doesn't even look similar to the kind of lending activities we did during the Great Depression," he said.

Mr. Plosser said the scope of today's global turmoil justified those actions. Still, he is worried perhaps more than most Fed members that returning to the bank's core mission -- price stability -- will be problematic.

"We've doubled the Fed's balance sheets in a month," he said. "We've injected a lot of liquidity into the banks, and at some point we have to take it back. It's not going to be easy."