If you agree—and only if you agree—Progressive Insurance will give you a device to install in your car that will rat you out for jack-rabbit starts and slamming on the brakes. * It’s a small thing that plugs into your on-board diagnostic system, and it transmits as you drive. If your little minder shows that you don’t act like Dale Earnhardt Jr. behind the wheel, you’ll save up to 30 percent on your auto insurance. Although there’s no official penalty for letting the company find out that you regularly lay down rubber, in fact you’ll pay more for coverage than will tamer drivers. You’ll also be acting to tame your own behavior by raising the price of recklessness.

Progressive’s driving spy is a sneaky example of the “precommitment device,” a technique that people use to bind themselves to their preferred desires, and a subject I have been studying for my new book about the problem of self-control, We Have Met the Enemy.

People have all kinds of desires, of course—even boring people like me, for whom a midlife crisis means not a red sports car but a nifty new Apple router. And all of us prefer some of our desires to others. For instance, you may want to knock back a few martinis at lunch on Thursday or sleep with your wife’s younger sister the next time you see her. But you probably also want to keep your job and stay out of divorce court. For obvious reasons these latter desires are the ones you prefer. The problem is, how to adhere to them?

Enter precommitment. On Wednesday, for example, looking ahead, you order a nice healthy salad to be delivered Thursday—and then you eat it at your desk, far from any sources of gin or vermouth. As for your sister-in-law, whenever you’re supposed to visit you find an excuse to stay away, thereby sheltering yourself from temptation.

But of course you could still ignore the salad on the desk and go out and drink your lunch, or you could take the radioactive sister-in-law to a concert. Most commitment techniques—including marriage—are just too easily circumvented.

That’s why truly binding precommitment devices are so interesting. The first known practitioner of such voluntary bondage was wily Odysseus, en route home from the Trojan War. As his ship approached the Sirens, he was determined to hear their song without, well, going overboard. Necessity being the mother of invention, he invented history’s first precommitment device. “You must bind me tight with chafing ropes,” our hero instructs in Robert Fagles’ translation, “so I cannot move a muscle, bound to the spot, erect at the mast-block, lashed by ropes to the mast. And if I plead, commanding you to set me free, then lash me faster. …”

What a moment! The Odyssey is really all about self-control, and Odysseus’ foresight and skill at managing desire explains why he—and he alone—survives the harrowing journey back to Ithaca. His actions in this instance set the standard for all who would later enlist others to compel themselves to follow their own commands.

Once you become aware of precommitment (the term was coined by economist Robert Strotz in 1956), it crops up everywhere. Thomas De Quincey, for example, tells us that Coleridge hired strong men to keep him out of opium dens—a practice that persists to this day in the “sobriety minders” who are hired to help celebrities keep their noses clean. The adventures of one real-life minder, however embellished, even became the basis of a TV show, The Cleaner. Following World War I, a disillusioned Ludwig Wittgenstein took great pains to give away his fortune irrevocably, just as armies in the past have burned their boats to make retreat impossible.

And let’s not forget Young Frankenstein, in which Gene Wilder asks to be locked in a room with the monster. “Love is the only thing that can save this poor creature,” he tells his aides, “and I am going to convince him that he is loved even at the cost of my own life. No matter what you hear in there, no matter how cruelly I beg you, no matter how terribly I may scream, do not open this door or you will undo everything I have worked for. Do you understand? Do not open this door.”

A minute later of course, he’s begging to be let out—but that’s the point. Precommitment works by putting the wrong choice beyond reach. And best of all, it’s voluntary.

The evidence is all around us that Americans are struggling—and often failing—to uphold their preferred desires. Hardly anyone wants to be fat, after all, yet two-thirds of us are. A large proportion of smokers have tried to quit. Most procrastinators would prefer to escape their dilatory impulses but struggle to overcome their powerful wish to avoid work.

The problem is that short-term rewards are just so much more seductive than long-term goals. And besides, what’s one little dessert, one more puff, or just a few more minutes at World of Warcraft when your thesis isn’t due for another year? People often understand how weak they are in this way, which is why (for example) they support the Social Security system, a giant precommitment device whereby we subject ourselves to taxation in order to forestall destitution that we could easily prevent if only we could save for ourselves.

How can you use precommitment to keep yourself from giving in to unwanted desires? You’re probably already doing so—for example, by asking your significant other, on the way to a restaurant, not to let you order dessert when you get there. Dan Ariely, that tireless student of human irrationality, has collected several interesting precommitment anecdotes from regular people, including one who placed her credit card in a container of water in the freezer, thereby requiring a cooling off—er, that is, warming up—period before use, and another who, before a date with a guy she knew she shouldn’t sleep with, wore her “granniest” underwear—presumably to deter herself from disrobing. In this she was unwittingly following the advice of St. Jerome, who argued that the determined virgin, “by a deliberate squalor … makes haste to spoil her natural good looks.” Jerome’s friend Paula, who ran a convent near his monastery in Bethlehem, evidently took the same view of cleanliness and chastity, warning, “A clean body and a clean dress mean an unclean soul.”

Most of us really ought to make more use of such techniques, as Dean Karlan and John Romalis did. The two economists each agreed to lose 38 pounds in six months or forfeit half his annual income to the other. They made a similar deal to keep the weight off afterward. This all worked well enough that Karlan later went on to found stickK.com, a Web site that allows you to provide a credit card number and make a legally binding agreement to do (or not do) a certain thing. If you fail—and you can appoint a referee to decide—then you forfeit the money, which the site will give to a friend or enemy you’ve chosen. (You can also choose a charity you like—or one you hate, such as the George W. Bush or Bill Clinton library, which might be even more motivating.)

As a libertarian-leaning Democrat, I’ve tried to think of ways the government might help us with precommitment. Some states and Canadian provinces already allow gamblers to bar themselves from casinos for a period of years. In British Columbia, some gamblers on the self-exclusion registry got in anyway and lost several hundred thousand dollars. They sued the province and the casinos for failing to do what Jenny Holzer said: “Protect me from what I want.”

What if we took this kind of thing further? One possibility might be to let people sign up to pay extra taxes based on the change in their weight. Health costs are largely socialized anyway, and there is precedent in the private sector, where insurers setting term-life premiums often take account of smoking, cholesterol, and other factors that individuals can influence. Another idea would be to require a driver’s license or other I.D. for the purchase of cigarettes or alcohol. The state would offer to emblazon these “NO TOBACCO,” for example, until the next renewal, perhaps three years later. During that time stores couldn’t sell you the stuff.

Modern life is a wonderful thing, rife with freedom and opportunity, but it comes with the problem of self-control. That’s a nice problem, since I can’t think of anyone else I’d want to be in charge. Yet most of us are probably kidding ourselves if we think willpower alone can do the job. Much better to make like Odysseus and face the music in safety.



Correction, Jan. 21, 2011: Thisarticle originally said the device from Progressive Insurance would rat you out for speeding. But while the device records your speed, it doesn’t know where you are, and the company says it can’t tell if you were violating any speed limit. Customers install the device only if they want to. (Return to the corrected sentence.) Like Slate on Facebook. Follow us on Twitter.