The United States job market has been improving. But is it close to being good?

That is one of the chief issues likely to be debated next week at the meeting of the Federal Open Market Committee. If it is close, and one traditional indicator seems to show that it is, then the time is near when the Federal Reserve should begin to tighten monetary policy. To not do so would be to risk a return of rising inflation.

But if it is not close, such a tightening could do serious damage to the recovery, hurting the prospects for employment of many who have been out of work for years.

Perhaps the most puzzling feature of the Great Recession and its aftermath was the sharp decline in the percentage of working-age people in the labor force. You have to be either working or looking for work to be in the labor force. People who are not looking are ignored when the government calculates the unemployment rate, which has fallen to 6.1 percent from a peak of 10 percent.

“This is involving millions of prime-age Americans who have dropped out of the work force,” says Andrew T. Levin, a research fellow at the International Monetary Fund who spent 22 years at the Fed, the last two years as a special adviser to Ben Bernanke and Janet Yellen, who were chairman and vice chairwoman at the time. “The question is, Do we give up on those people?”