As the heady days of the 1980s recede, one part of the hangover many employees are starting to feel is the shift in the way many companies operate their pensions.

To a far greater extent than at any time since corporate pensions became commonplace, workers are being asked to direct their own pension investments and bear the risk that their strategy will not pay off.

A generation ago, companies bore that risk. Most pensions provided benefits based on a formula, usually related to pay and length of service, and it was up to the company to provide a fund adequate to the task. Such arrangements are still common, particularly at large companies, but they are increasingly meant to be supplemented by the worker's own investments. And in many cases, especially at small companies, the worker must do it all.

During the '80s, as the stock market and the economy boomed, workers often applauded the change. They got a pension that was portable -- a real benefit if they changed jobs -- and instead of some arcane formula they got a real account and could watch its balance growing.

But experts worried -- and still worry -- that most workers were too conservative.

Various studies have found that a substantial majority of the money workers commit to their "defined benefit" pensions -- those on which they bear the investment risk -- goes into fixed-income investments. For example, by one count, two-thirds of the money in 401(k) accounts today is in guaranteed investment contracts, which promise a certain return for a set period of years.

While there have been periods in recent history when fixed-income investments did very well, over the long run the stock market has outperformed most anything else you can think of.

However, as the accompanying chart illustrates, the market's performance has been anything but even. In fact, using the Dow Jones industrial average as a gauge, only three decades have shown more than passbook savings-sized growth, and one of these was the 1980s.

And within the '80s a similar picture emerges. Charles Salisbury of T. Rowe Price Inc., the big Baltimore-based mutual fund operator, points out that if you exclude five particularly good months from the 1980s, the market provided little more than a Treasury bill return.

In other words, $1 invested in the Standard & Poor's 500 stock index (a broader gauge than the Dow Jones industrials) grew to $5.02 during the decade. But if run-ups in November of 1980, August and October of 1982, August of 1984 and January of 1987 were taken out, the $1 would have grown only to $2.92, while $1 invested in Treasury bills would have grown to $2.35.

But Salisbury has other calculations as well. Studying the market's performance in the aftermath of eight post-war crises, including the outbreak of the Korean War in 1950, the first OPEC oil embargo in 1973 and the October 1987 market crash, he finds that the Dow Jones average declined an average of 19 percent, reaching bottom on average five weeks after the crisis. But in all cases but one -- the oil embargo -- the average had more than recovered those losses within a year.

The lesson, Salisbury said, is that "people who did not abandon ship were rewarded henceforth."

Does that mean they will be again? Salisbury thinks that, on balance, "this is not the time to be selling stocks if you have them, and if you have some liquidity, you should be buying."

On the other hand, Camillo A. Schmidt of Potomac Investment Management Inc., a private portfolio management company in Glen Echo, thinks that stocks that do well "will be the exception, not the rule" in the near term, and that with the economy in the shape it's in, "any outlook on equities must be tempered."

" ... The only thing one can say with any sense of certainty is that whatever happened in the immediate past is unlikely to happen in the immediate future," said Schmidt, whose firm manages portfolios of $175,000 and up for individual investors.

In other words, don't expect a rerun of the '80s in the '90s.

What does all this mean for people trying to assure themselves a comfortable retirement?

First, unless you like investment management, or unless you expect to be changing jobs, don't let your employer talk you into giving up your old-fashioned defined benefit pension plan -- where the employer does the investing.

If you have to bear the risk, diversify. Don't let the current market slump scare you out of stocks entirely. Only in the Depression did stocks actually lose money over a decade, and if you are to catch the special months in the special decades, you have to have money already in the market -- "have your line in the water," as the sayings goes.

The younger you are, the longer you can wait for the big one, so you can afford to take more risk. Salisbury said as a rule of thumb, people might consider having 10 percent of their portfolios in fixed-income investments for each decade of their lives. In other words, if you are in your fifties, you should have 50 percent in fixed-income, "climbing toward 60 percent as you near 60," he said.

Said Schmidt, "Not to sound cynical, but my view of the market is it's not likely to make somebody rich. It is likely to provide for specific goals -- retirement, the education of a child or even a trip. If you have a specific goal in mind, the market can come into play, recognizing that {investments are} a competitive marketplace, and you need to look at bonds," certificates of deposit and other investments as well.