The trend challenges conventional wisdom that entrepreneurs are mostly young. They're just as likely to be folks like Franny Martin, who launched a Michigan cookie company in 2002 when she was nearly 56.

Business is hot: She expects $500,000 in revenue this year, nearly triple last year's.

"I'm thrilled!" says Martin, a 30-year corporate veteran.

Older Americans are entrepreneurship's bright spot. Overall self-employment fell during most of the past decade, edging up only recently.

That weak performance is worrisome because entrepreneurs fuel the economy by buying computers and other goods and by creating most new jobs and innovations.

To be sure, entrepreneurship isn't a slam-dunk for older corporate refugees. They often lack skills, such as tech know-how or marketing smarts. They may underestimate healthcare and other startup costs. And they risk gambling retirement savings on a venture that may go belly-up.

"People tend to romanticize self-employment. They think everyone will wind up like Steve Jobs," the Apple Computer co-founder, says Jules Lichtenstein, a senior policy adviser at AARP, the advocacy group for seniors.

Despite the risks, more older workers are coming to entrepreneurship's rescue.

Boomers want the security of being their own boss when corporations are slashing payrolls, tossing fiftysomethings into a dicey labor market. One-third of AARP members work, and many need to work past the traditional retirement age of 65.

Near Atlanta, Jim Minick, 51, started an elderly care business in 2003 because he feared another layoff. His Home Care Georgia in Smyrna helps people with daily tasks at home, such as getting dressed. It became profitable in 2004. Minick expects more than $140,000 in revenue this year.

In 25 years of human-resource and sales jobs, Minick was laid off three times.

"You don't want to find yourself 55 or 60 with no one wanting to hire you," he says. "That's a concern with any 50-year-old."

Older workers want more flexible schedules to spend time with aging parents or on hobbies while easing into retirement.

Near Phoenix, Bill Gluth, 54, started a small-business consulting firm in 2001 after leaving a marketing job at a graphics company. He expects to take more annual vacation: as much as two months.

That's typical of entrepreneurs 50 and older, research by think-tank Rand found. About 41 percent work part-time versus just 26 percent of workers that age employed by others.

The number of Americans age 50 and up will soar by 31 million to 118 million from 2005 to 2020, predicts the Census Bureau. Much of that is fueled by the baby-boom generation.

Growth also is driven by rising life expectancy, giving workers a shot at a second career as entrepreneurs, says Jim Hoopes, a business history professor at Babson College.