That is why Joan Campagna planned to wait until age 70 to retire.

"I'm worried," said Ms. Campagna, who lives in Fort Myers, Fla., and was 64 years old in April when she lost her job as an executive assistant at a small public-relations firm. In June, she began withdrawing her Social Security benefits, six years earlier than intended. As a result, she is receiving $1,417 per month, about $600 less than if she waited until age 70. "I want to be sure that I can support myself," she says of her unplanned early retirement. "That's my biggest concern."

The U.S. Social Security Administration, which was established in the wake of the Great Depression under President Franklin D. Roosevelt, saw a 21% surge in applications for retired worker benefits for the fiscal year ended Sept. 30. Only about 15 percentage points of that was expected from a surge in baby boomers and working women reaching retirement age, according to Stephen Goss, the agency's chief actuary.

Ms. Coile and Mr. Levine's research indicates that many of those who retire for lack of work are less educated, earned lower incomes and were less likely to have investments or other sources of income, meaning they are more reliant on Social Security payments during their retirement, and more adversely affected when those payments are reduced.

The end result, said Ms. Coile, is that "it leaves workers forced into retirement by a late-career layoff with lower income and a higher risk of poverty."

That effect is already being felt by food pantries, homeless shelters and people like Guy Kelley, director of the Merrimack Valley Community Service Corps based in Lawrence, Mass., who said he has a waiting list of 15 to 20 applicants for the 50 or so slots in his "foster grandparent" program, which pays a meager hourly stipend of $2.65.

"There are people clamoring for these positions," Mr. Kelley said. "That basically means people either can't find work or have given up and are desperate for anything right now."

Among 55- to 64-year-olds, unemployment was 7% in November, up from 6.6% in October, despite a decline in overall unemployment. That is more than double the rate when the recession began, and the highest seen in November since the Labor Department's records began in 1948.

And these unemployed jobseekers say it is even more difficult for them to find work because of what they see as age bias.

"Employers think that I can barely check my email," says Bob Bellin, a 55-year-old unemployed executive in Cleveland who describes himself as tech-savvy. The former chief executive of a billboard-advertising company has been job hunting since early 2008. "My fear is that by the time the economy improves, I'll be a guy who's 58 and out of a job for three years, and...that guy probably doesn't have much of a shot."