OPINION: Why we sometimes tie our own hands

Daniel Akst is author of the forthcoming book "We Have Met the Enemy: Self Control in an Age of Excess."

Politicians on all sides, it seems, are tossing their caps in the air.

Faced with election-year ire over the state's crushing property-tax burden, Gov. David A. Paterson has proposed a legislative cap of roughly 4 percent on annual increases in the widely resented levy. Gubernatorial hopeful Attorney General Andrew Cuomo has gone further by proposing a 2 percent annual cap.

Is capping property taxes a good idea? From a policy standpoint it's debatable, but limiting spending by forcibly constraining taxes makes perfect sense to students of human nature.

In fact, measures like a property-tax cap are among the oldest and most effective techniques governments (and people) use to control their own unwanted behavior. The folks who worry about these things professionally - economists, psychologists and the like - call these tactics commitment devices.

Armies that burned their boats after landing on some distant shore did something very similar, much like the disgruntled employee who burns his bridges by firing off some vituperative e-mail as a parting shot. Dieters do the same thing when they avoid buying ice cream to keep themselves from eating any - or have their jaws wired shut, if buying the ice cream was just too tempting. Taxpayers who elect to overpay the Internal Revenue Service all year, forgoing interest in order to get a fat refund later from Uncle Sam, are in the same boat.

Governments have a hard time similarly binding themselves because later politicians can undo the constraints imposed by earlier ones. But governments can also make the constraints very hard to undo.

In the U.S. Constitution, for example, politicians in the 18th century adopted a document that not only constrained their successors - by banning any laws limiting freedom of speech or religion, for example - but also made their handiwork really hard to reverse. The Constitution contains a clause that makes amendments difficult by requiring approval from "three fourths of the several States."

The Social Security system is perhaps the nation's most beloved commitment device, and voters strongly support it. Why should this be, when they could easily save the money for themselves rather than paying it to the government in the form of a payroll tax? The answer is that they know themselves - and they don't trust themselves to do the saving that the government forces on them. The remarkable thing is that they trust the government to pay them back years down the road when they retire.

People like to be able to commit themselves, which is why they persist in getting married. A few states even offer "covenant marriage," a kind of super-matrimony that is harder to get into - and out of. With divorce now commonplace and relatively stigma-free, covenant marriage comes closer than the regular kind to being binding, which is what any truly effective commitment device needs.

Unfortunately, even binding commitment devices can fail. The European Union caps national deficits, but member states often spend their way right through them. Closer to home, legislators in Albany passed a law in 1998 that certainly seemed binding: If they don't adopt a budget for the state by April 1, they don't get paid until the job is done. Regardless, the lawmakers have repeatedly failed to adopt a budget.

So will a legislated limit on property taxes stick? In all likelihood it will, as it has in California and Massachusetts, for the simple reason that the voters will insist, just as they have with Social Security. Politicians won't dare cross them on such an issue - proving that some caps, once donned, are awfully tough to remove.