To Explain the Fed, Choose a Vice

The search for the best metaphor to describe the tapering of the Federal Reserve’s monthly bond purchases later this year rolled forward on Friday.

The latest contestant is the Richmond Fed president, Jeffrey Lacker.

“The Federal Reserve is not only leaving the punch bowl in place, we’re continuing to spike the punch, though at a decreasing rate over the next year,” Mr. Lacker said.

This was reminiscent of Thursday’s best effort, which also invoked an addictive vice.

“It seems to me,” said Dennis P. Lockhart, president of the Federal Reserve Bank of Atlanta, “the chairman said we’ll use the patch â€" and use it flexibly â€" and some in the markets reacted as if he said ‘cold turkey.’ ”

(Mr. Lacker was riffing on a famous description ofcentral banking by a former Fed chairman, William McChesney Martin. The job, Mr. Martin said, is “to take away the punch bowl just as the party gets going.”)

The point that Fed officials are trying to make is mathematically straightforward. Since December, the Fed has expanded its holdings of Treasury securities and mortgage-backed securities by $85 billion a month. Starting later this year, perhaps in September, the Fed is going to buy less each month.

But - this is the key - the Fed will still be expanding its portfolio. More alcohol! More nicotine! More stimulus for the American economy!

It is relevant at this point to note that neither Mr. Lacker nor Mr. Lockhart is among the strongest supporters of the Fed’s efforts. The supporters tend to favor metaphors less freighted with negative connotations.

Consider the choice of the chairman, Ben S. Bernanke:

“To use the analogy of driving an automobile, any slowing in the pace of purchases will be akin to letting u! p a bit on the gas pedal as the car picks up speed, not to beginning to apply the brakes,” he said last week.

Ah, that’s much more dignified. The Fed as designated driver rather than enabler.

Except, of course, that markets didn’t get Mr. Bernanke’s point, which is the reason we are now enduring the other metaphors.