NEW YORK — Why is it so devilishly difficult to save for retirement? Humorist Ben Stein — who's an economist by training — thinks he has the answer.

"You've got an angel on one shoulder saying, 'Be prudent and prepare for your future,' " he says. "But the devil's on the other, saying 'No, enjoy yourself right now. Live it up and buy whatever you want.'

"Let's face it, the devil is much more fun to deal with."

Stein is the spokesman for the National Retirement Planning Coalition, a group of consumer advocacy and trade associations that sponsors an annual retirement planning campaign.

His aim this year is to convince Americans that to have a comfortable retirement, they need to better balance their short-term spending with long-term savings.

"I know I had to change my own mind-set," Stein said in an interview, clad as usual in dress suit and sneakers. "We all buy to feel good. But now every month I feel good looking at my (financial) statements."

Many more Americans need to change their own psychological approach to spending and saving if they're going to have enough money when they stop working.

A recent study by the nonprofit Employee Benefit Research Institute in Washington, D.C., found that half of all workers have saved less than $25,000 toward retirement.

The more-earnest savers have done better, with workers who have invested in company-sponsored 401(k) retirement accounts for at least six years averaging $91,042 in savings at the end of 2004, EBRI found. The account balances of workers in their 60s averaged $136,400, it said.

That may sound like a lot of money, but it has to last a long time. Americans are living longer and often face escalating healthcare costs as they age. At the same time, company pensions and retiree health benefits are being slashed, and the Social Security system may not be able to sustain the payments it makes now.

"The devil is saying, 'The government will take care of you, your employer will take care of you, some mystery agency will come from nowhere and take care of you,' " Stein said. "You have to know that you have to take care of yourself."

The key is to start saving sooner rather than later.

Robert J. Reby, a financial planner based in Danbury, Conn., and the author of "Retire Without Worry," says that people should begin by estimating how much money they need to support the lifestyle they want in retirement.

There's no correct answer, he added, saying: "We have some clients that need $1,200 a month and some clients that need $35,000. The most typical is $5,000 to $6,000 a month."

Once you've got a retirement goal, you can step up your monthly savings to try to reach it, Reby said.

Americans of all ages are more aware of the importance of saving and investing for retirement, thanks to company education efforts, the media, financial planners and adult education courses, Reby said.

"The challenge is converting the knowledge to action ... about taking care of yourself and living within your means," Reby said. "If you don't, all that awareness and sophistication doesn't do a lot of good."