The Federal Reserve will keep its "extraordinary" support for the economy for "some time to come," Chairman Janet Yellen said Monday in Chicago.

Labor conditions are worse than indicated by the falling unemployment rate, as evidenced by the low participation rate seen in recent months, according to Yellen.

She noted there are 7 million people working part time but who would like a full-time job.

"This number is much larger than we would expect at 6.7 percent unemployment, based on past experience, and the existence of such a large pool of 'partly unemployed' workers is a sign that labor conditions are worse than indicated by the unemployment rate."

In another sign that the jobs market has not quite healed, the number of people who voluntarily quit their jobs "is noticeably below levels" before the recession.

"For the many reasons I have noted today, I think this extraordinary commitment is still needed and will be for some time, and I believe that view is widely shared by my fellow policy makers at the Fed," Yellen said.

RTTNews