Once again, President Clinton has all of Washington discussing the unmentionable in public. I refer, of course, to Social Security. Reform of our demographically challenged retirement program, once politically impossible, was designated officially discussable by the president’s State of the Union address in January.

Some people advocate tiny tweaks to the system, like raising the retirement age, cutting benefits or hiking payroll taxes. Others — like me — prefer privatizing Social Security: permitting workers to privately invest their payroll taxes in stocks, bonds and the like. (Characteristically, the president is doing his best to straddle the debate; he announced that he’d accept a little privatization, but only in the context of preserving the system.)

The moral and intellectual appeal of letting working-class people accumulate retirement savings the same way middle- and upper-income people always have — through investments that appreciate at market rates — is forcing defenders of the current system to attack privatization. Since everyone knows that stocks and bonds will give a better return to investors than the special-issue U.S. Treasury bonds that the Social Security Administration is required by law to buy, some who favor the current system are doing their best to obscure the workings of both Social Security and a privatized retirement system.

Take a Herblock cartoon in the Washington Post captioned “Have We Got a Deal for You!” A grinning privatization advocate attempts to persuade a baby boomer, while in the background a gigantic bull representing the stock market leaps into the air. Herblock, whose New Deal loyalties have remained unchanged in over a half century of cartooning, is suggesting in his characteristically unsubtle way that the bull market must soon come back to earth. A moment’s thought reveals the cartoonist’s power to have it both ways: imagine what Herblock could do with this material if the market were in free fall!

In any case, snapshots of stock market fluctuation miss the point: no one should make retirement investments expecting a quick gain. Investments in stocks will likely net an annual 10 percent return over the long run. Compare this to what young workers will get under the current system: a negative return. They’d be better off if Social Security had never existed.

Despite the comforting vision of “ensured” benefits, government spending programs are not immortal, especially those funded by payroll taxes that would dwindle with rising unemployment.

Henry Aaron, a Brookings Institution economist, makes two other arguments against privatizing Social Security. They do little more than unwittingly highlight the flaws of the current system. First, he suggests that the government could administer a complex retirement program far more cheaply than the private sector could. That’s not obvious; people unimpressed with the efficiency of (for instance) the post office would surely disagree.

But Aaron makes a more interesting argument about the present program: he says it serves as “social insurance.” “One needs to remember why we have social insurance. It is to ensure that people have a reliable income floor when retirement, death, or disability cuts their earnings and that this income bears some relation to what they previously earned. Such income should not depend on what happens to stock and bond prices or whether people choose their investments wisely. It should be ensured.”

Such lofty sentiments conceal the way Social Security really works. There’s no way to guarantee Social Security benefits unless you’re comfortable with huge future tax hikes. All the soothing rhetoric in the world about ensuring an income floor doesn’t hide the fact that wishing won’t make it so. Someone still must pick up the tab for Social Security payouts. Social Security investments in Treasury bills are slightly safer than burying money in the backyard. Over time, you can bet that inflation will consume capital.

Opponents of privatization are not shy about predicting an economic collapse that would harm investors. Sure, another depression that delivers a body blow to the financial markets could happen. But assume it does: it would have an equally devastating effect on our current, already unsteady retirement system. Despite the comforting vision of “ensured” benefits, government spending programs are not immortal, especially those funded by payroll taxes that would dwindle with rising unemployment.

In any case, even the worst two decades of modern American economic history — the period around the 1929 crash and the Great Depression — saw an annualized stock market return of over 3 percent; that miserable return is a better rate than the one I’ll get from the current system.

The wonderful thing about insurance is that it’s capable of funding itself; the terrible thing about Social Security is that it isn’t. People buy insurance to hedge against catastrophic and unpredictable events like loss of life, property or occupation. Aging is sometimes unpleasant, but it is surely predictable. No insurance salesman would write you a policy against getting old, or anything else that happens with such clocklike regularity. Historically, people have dealt with old age by saving for it. Privatization would reinforce that kind of healthy behavior rather than the dependence that the current system seems to encourage.

Aaron argues that people shouldn’t be allowed to “play financial roulette” with retirement savings. That’s a cheap shot, since — over time — gamblers fighting the house edge lose, investors in T‑bills come out about even, and stock market investors can be expected to win. In any case, the current system threatens to come up on double zero.