Why make New Year's resolutions? If you need to start a diet or get up earlier in the morning, why wait until Jan. 1? Why not do it any day? New Year's resolutions do not make any sense.
While perfectly logical, however, that analysis misses the point. New Year's resolutions help people cope with some of the most difficult conflicts human beings face.
So argues one of the economics profession's greatest experts on conflict, Thomas Schelling, who shared the 2005 Nobel in economic science for, in the words of the citation, "having enhanced our understanding of conflict and cooperation through game-theory analysis."
Schelling, a professor emeritus at the University of Maryland, is famous for his work on conflicts between nation-states, particularly those with nuclear weapons.
One of his best-known ideas is "precommitment." One party in a conflict, he demonstrated, can often strengthen its strategic position by cutting off some of its options to make its threats more credible. An army that burns its bridges, making retreat impossible, is a classic military example. Others involve strong diplomatic commitments. By passing a law saying the US will defend Taiwan if it is attacked, for example, Congress gives future administrations less flexibility in dealing with a crisis, but the threat makes an attack less likely. In the early 1980s, Schelling applied similar analysis to individuals' internal struggles, seeking to develop what he called "strategic egonomics, consciously coping with one's own behavior, especially one's conscious behavior."
The problem, he suggested, is that pretty much everybody suffers from a split personality. One self desperately wants to lose weight or quit smoking or get up early to work. The other wants dessert or a cigarette or loves sleep.
Both selves are equally valid, and equally rational about pursuing their desires. But they do not exist at the same time.
"What I have in mind is an act or decision that a person takes decisively at some particular point in time, about which the person's preferences differ from what they were earlier, when the prospect was contemplated but the decision was still in the future," he wrote in Ethics, Law and the Exercise of Self-Command.
"If the person could make the final decision about that action at the earlier time, precluding a later change in mind, he would make a different choice from what he knows will be his choice on that later occasion."
New Year's resolutions help the earlier self overrule the later one by raising the cost of straying. "More is threatened by failure than just the substance of the resolution: One's personal constitution is violated, confidence demoralized, and the whole year spoiled. At least one can try to make it so," Schelling wrote in The Intimate Contest for Self-Command a 1980 essay in his book Choice and Consequence: Perspectives of an Errant Economist.
As many a broken resolution demonstrates, those consequences are not a very big enough deterrent. To make success more likely, Schelling suggests a few additional strategies.
One is a mild precommitment: not keeping sweets or tobacco in the house, for instance. At the very least, this forces you to delay indulgence until you can go to the store -- and possibly to recover your resolve.
Another approach is to use bright-line rules, which make it harder to cheat through clever reinterpretation. That may explain why many people find it easier to eliminate whole categories of food, like carbohydrates, rather than simply cut back on calories.