Jobless Americans who dropped out of the work force typically searched for work for five months before ultimately giving up last year.

The amount of time the unemployed spent hunting for jobs rose sharply last year. Those out of work tended to search for about 20 weeks before quitting in 2010, compared to 8.5 weeks in 2007, according to a recent Labor Department report. The report studied how long unemployed workers took to either find a new job or quit looking. Labor-force participation, the share of Americans who are working or looking for jobs, has fallen to its lowest percentage since the mid-1980s. That’s partly because people have grown discouraged about their ability to find jobs and have given up looking. With those workers on the sidelines, the unemployment rate has been lower than it otherwise would be. The official unemployment rate hit 9.1% in May. Including all of those who had part-time jobs but wanted to work full-time as well as those who want to work but had given up searching, the rate was 15.8%.