"About the same amount I made 30 years ago," Wood, 69, says of his $12 hourly wage. "I'm worried about my portfolio because of low interest rates, even to the point of considering full-time again."

Feeble returns on the safest investments such as bank deposits and fixed-income securities represent a "financial repression" transferring money from savers to borrowers, says Bill Gross, manager of the world's biggest bond fund. Workers 65 and older, struggling with years of depressed yields, are the only group of Americans who are increasingly employed or looking for jobs, according to Labor Department participation-rate data.

"We're going to be financially repressed for decades," Gross, the 69-year-old billionaire co-founder of Pacific Investment Management Co., told Bloomberg Radio Feb. 7, citing Federal Reserve interest-rate policy that aims to cut borrowing costs. "I hate to be gloomy, but, yes, for the next 10 years, the oldsters, and I'm in that camp, are going to be disappointed in terms of the policy rate."