But influential Fed officials see little harm in postponing the decision, particularly compared with the risks of pulling back too soon. Significant details of the eventual retreat also remain the subjects of unresolved debates, according to the public statements and interviews. And some officials argue that the slow pace of inflation is itself a reason for the Fed to maintain its stimulus campaign.

“Everything else equal, I would like to see a couple of months of good numbers,” Charles L. Evans, president of the Federal Reserve Bank of Chicago, told Reuters on Friday, referring to the relatively strong jobs numbers in November.

Mr. Evans added that he was “certainly nervous” about the sluggish pace of inflation. Rising prices can help stimulate the economy, making it easier for companies to increase profits and for borrowers to repay debts. Inflation also encourages people and businesses to borrow more money and to spend it more quickly.

Low inflation reduces those incentives. It also means the economy is closer to deflation, or a general decline in prices, which has the opposite effect: freezing economic activity by discouraging both borrowing and spending.