More than 15.4 million American workers aged 20 or over lost their jobs, or 11 out of 100 adult workers, during the three-year period from 2007 through 2009, according to the Northeastern University's Center for Labor Market Studies, in Boston, who analyzed U.S. Bureau of Labor statistics.

"It was the most workers ever found to be displaced, the highest displacement rate, and the lowest re-employment rate" in the 30-year history that the Bureau of Labor has kept statistics on job losses, said the school's Joseph McLaughlin, one of the authors of the report, sponsored in part by the Alternative Schools Network in Chicago.

The 18-month downturn dubbed the Great Recession began in December 2007 and ended in June 2009, but the subsequent economic recovery has been sluggish and particularly slow to produce the positions needed to get people back to work and absorb new workers.

Teenaged workers, whether it was students seeking summer jobs or school dropouts and graduates looking for full-time work, were particularly hard-hit by joblessness. Only one in four U.S. teenagers held a job in 2011, the smallest percentage in decades and half what it was in 1999-2000.

A weak job market hurts teenagers most, McLaughlin said, because employers need not hire inexperienced and younger workers because there are plenty of adults seeking work.

"We find that early work experience really helps prepare them for full-time work. It also boosts their earnings later on," he said of teenaged workers.

The issue of youth employment entered the Republican presidential campaign debate when former House Speaker Newt Gingrich suggested school-age children be employed sweeping up schools to gain experience and earn some money.

"I give him credit for identifying the problem -- just not the way he tried to solve it," McLaughlin said.

SLUGGISH RECOVERY

During the full years 2007 to 2009, the average number of newly "dislocated workers" -- defined as jobs lost because the company closed or moved, or there was insufficient work, or the position or job shift was eliminated -- was 5.14 million, compared to the next-highest yearly level of 3.8 million workers who lost jobs during the 2001-2003 period.

"The numbers are nearly double to what we've had before. It's not even close to what we've seen in the past," McLaughlin said.

Of those who lost jobs during the three-year period, 49 percent had gotten a new one by January 2010, the lowest rate of re-employment since the Bureau has compiled statistics.

Overall, workers who got new jobs earned 7 percent less than they did before, according to the report.

Education provided some protection from job loss during the three-year period from 2007 to 2009, the report found. Among high school dropouts, 15 percent suffered job "dislocation," compared to 13 percent of high school graduates, 8.5 percent of those with college degrees, and 6 percent of those with Master's degrees.

Job losses hit hardest in the construction and manufacturing, according to the report, with roughly one in five workers in those industries losing jobs. One in 10 financial service workers were let go, and one in 20 in education and healthcare lost jobs.

(Reporting By Andrew Stern)

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