Although employment is recovering, with the most recent unemployment rate at 5.1%, there remain large numbers of people who have left the workforce.

The percentage of those working or who are looking for work is at 62.4%, the lowest reading since October 1977. The index peaked in 1997 at 67.2%, according to the Bureau of Labor Statistics.

Some of the drop can be linked to the number of baby boomers retiring. Others have left the workforce because the Affordable Care Act means that they don’t have to stay on a job to keep health insurance.

But others still haven’t seen the recovery from the Great Recession, which began at the end of the George W. Bush presidency. Participation is even lower among those in their prime earning years, from 25 to 34, when most Americans are on their own. That number is now at 80.6%, down from 84% in early 2008.

Pessimistic analysts are looking for the trend to continue. “A further decline in the participation rate suggests the U.S. labor market is undergoing a significant slowdown in the second half of the year,” Lindsey Piegza, chief economist at Stifel, Nicolaus & Co., told MarketWatch.

-Steve Straehley

To Learn More:

Share of Americans in Labor Force Shrinks to 38-Year Low (by Jeffry Bartash, MarketWatch)

Labor Participation Rate (ZeroHedge)

How America’s Workforce Has Changed Since 1977 (by David A. Graham, The Atlantic)

Percentage of Americans with Jobs Hits 31-Year Low (by Noel Brinkerhoff, AllGov)

Percentage of African-American Adult Men with Jobs Hits Record Low (by Noel Brinkerhoff and David Wallechinsky, AllGov)