It's getting more common—and not just because times are tough

Although "early retirement" remains a dream and a goal for many American workers, the reality is that the average age at which people expect to retire has been creeping up steadily over the past several years, according to data from the 2009 Employee Benefit Research Institute (EBRI) Retirement Confidence Survey. In fact, since 1991, the midpoint age at which people plan to retire has increased from 62 to 65, and the percentage of people still in the workforce at age 55 has increased steadily since 1993.

And in 2009, lots of people decided to postpone leaving the workforce for two very obvious reasons: an economy mired in recession and a stock market downturn that left many would-be retirees feeling poorer than they'd like. In fact, according to the survey, 36 percent of the respondents cited the poor economy as the reason for delaying their retirement in 2009; another 28 percent cited the need to make up for stock market losses.

No surprise there: Hard economic times and falling asset values make the prospect of retirement a scary one—and it's a big enough challenge even when times are good.

But here's the good news. Working longer can be a very rational and productive strategy to deal with economic and investment challenges. And the benefits may be even greater than you might think at first blush:

• Working longer means you postpone tapping your retirement assets. The longer you wait, the longer those assets are likely to last—plus your retirement funds stay invested and have the potential to grow.
• Staying on the job also means you'll have more opportunities to add to your retirement assets through tax-advantaged retirement plans like 401(k) or IRA accounts. (Don't forget: people 50 and over can make catch-up contributions of up to $5,500 in 2009 to their 401(k) or 403(b) accounts and an additional $1,000 to an IRA).
• Remaining in the workforce probably keeps you on the company health plan, a huge plus.
• Working longer also means you should be able to postpone taking Social Security benefits—the longer you wait (up until age 70), the bigger the benefit.
• Finally, there are many who believe that working keeps you younger. It's important, and healthy, to stay active and engaged, and having a job can be an ideal way to do so.

Be warned however: Not everyone who wants to keep working gets to. In fact, the EBRI study found that 47 percent of retirees in 2009 left their jobs earlier than expected because of health reasons, changes at their companies, and other reasons.

Of course, if you're ready to retire—that is, if you're financially prepared and you're ready to leave the workforce—go for it! But if you're worried about your ability to retire comfortably, consider postponing your retirement. Keep working and saving aggressively. You'll definitely increase your chances of having a financially secure retirement. And if you enjoy your work, why give it up in the first place?