Change: U.S. work force smallest as a percentage since 1983

Only 45.4% of Americans had jobs in 2010, the lowest rate since 1983 and down from a peak of 49.3% in 2000. Last year, just 66.8% of men had jobs, the lowest on record.

The bad economy, an aging population and a plateau in women working are contributing to changes that pose serious challenges for financing the nation’s social programs…

Other key findings:

•Men leave. Working-age men have been dropping out of the labor force for decades. The disappearance quickened when construction and manufacturing jobs vanished in the recession from December 2007 through June 2009. Until the 1960s, more than 80% of men worked.