The trustees of the Social Security trust fund recently had some good news for U.S. taxpayers. Without any changes in taxes or benefits, the system will remain solvent until the year 2037, not 2034 as projected last year.

This marks the third year in a row the system's projected financial difficulties have been moved further into the future. Why is it, then, that supporters of Social Security are on the defensive? Why do private accounts still have so much appeal?

The answer certainly is not that the system is in crisis. Shortfalls in Social Security revenue are as imminent today as the Y2K crisis was in 1963. "Only 37 years left" is not the sort of call to action that will draw a large crowd.

Any forecast 37 years into the future is more hunch than science, anyway. It was only a few years ago an eminent economist promised to eat his hat if the federal budget achieved a surplus by 2002. Social Security projections are hardly more reliable than the forecast that cost that economist his hat.

People don't trust Social Security because we pay so much into it and seem to get so little in return. The average family pays more in Social Security contributions than federal income taxes.

Retirees, on the other hand, receive only $ 804 monthly, on average, in benefits. It seems obvious a good investment advisor could get a better return on all the money is being paid into Social Security.

There are two reasons you have to pay in so much to Social Security compared with what you get back. First, Social Security is not just a retirement plan, it provides for the survivors of workers who die young (life insurance), it supports those with career-ending injuries (disability insurance) and protects retirees from the rising cost of living (inflation insurance).

Second, and this is a key point, Social Security is not an investment at all. The Social Security system doesn't invest your money, it doesn't save much either. Instead of investing workers' taxes, it has been spending them.

Does the system provide jobs and perks for armies of bureaucrats? No, in fact Social Security is extremely cost-effective, much cheaper to run than a typical private investment fund. Costs of running the system are less than 1 percent of contributions. Does it divert money to pay for wasteful public programs?

No, when the Treasury borrows from the relatively small Social Security trust fund, it pays the same return on its bonds as it pays to millions of private investors.

This is what happens to your Social Security tax dollars: Most flow out that same year as benefits to retirees. Almost from the start, Social Security used tax contributions to pay benefits to current retirees.

The idea was the people who paid those taxes would be supported in retirement by the next generation of taxpayers. The Social Security contributions of the early taxpayers could have been used to build up investments to pay for their retirement, and so on.

But instead of waiting many years to start paying benefits, Social Security taxes were paid out immediately as benefits to retirees. When those taxpayers retired, the next generation of taxpayers supported them. And so on. For 70 years, we have been encouraged to think of Social Security taxes as contributions to an investment fund.

They are not. They are payments to our parents and aunts and uncles, payments that will be replicated when we retire and our children pay for our retirement.

The appeal of private investment funds comes from a deliberate distortion of Social Security, in which an intergenerational transfer system is compared with an investment system.

Private saving accounts for retirement are a great idea, but they cannot come at the cost of shunning our responsibilities to earlier generations of workers.

The $804-a-month average benefit makes up the majority of income for all but the top 40 percent of retirees. Private retirement accounts can only come on top of Social Security, not instead of it. Social Security taxes are spoken for and they are being well spent.

Bernard Wasow is a senior fellow at The Century Foundation. This article originally appeared in Bridge News on April 11, 2000.