Economics and New Year’s Resolutions

In recent days, we’ve introduced a pair of regular guest bloggers, Ian Ayres and Sudhir Venkatesh. We are happy and proud to now introduce a third, a terrific addition and no stranger to readers of this blog: Justin Wolfers, an economist at Wharton and a great explorer of everything from racial bias in N.B.A. refereeing to the decline in women’s happiness to divorce myths.

With the holidays upon us, it’s hard not to turn the economists’ gaze to the rituals around us. So let me ask, what exactly are New Year’s resolutions about? Here are seven theories, collected around my Christmas Eve table:

1. Aspirations: a statement (to self; to others?) of who and what I want to be. New Year’s Eve is simply a focal point for this statement of aspirations.

2. Commitments to self (or my future self): a statement of what I want to be. And if I don’t achieve it, I will be left with the guilt of not having lived up to a promise to myself. If that is costly enough, then the commitment may be useful.

3. Commitments to others: many of us describe our commitments to our friends. Henceforth, it is their job to hold us to it, or else to make us feel bad. Describing my commitment to my friends is like posting a bond, based on my future good behavior. (And perhaps this is a less costly commitment than betting at Stickk.com).

4. A clean slate: we rarely respect the irrelevance of sunk costs in our behavior. The New Year is a clean slate. If my behavior is history dependent (why not eat the chocolate cake if I’m already overweight?), then the clean slate allows my behavior to escape past poor behavior.

5. A signal: I only get to make a small number of resolutions, and so making a resolution about fitness is credible, relative to the fact that I chose not to make a resolution about tardiness. (In this sense, it is like the A.E.A. signaling system, where aspiring assistant professors can make a New Year’s resolution that they really, really would like to work at two specific universities.) Perhaps related to Nos. 2 or 3.

6. Intertemporal reallocation: diets in January follow gluttony in December. Or hard work in January follows slacker time in December. And this is more efficient than forgoing all that terrific food/all those wonderful celebrations/all that time off in December. By this theory, it isn’t surprising that so many resolutions are about health/diet/fitness, and it isn’t any concern that we rarely respect these resolutions past February.

7. Cheap Talk: New Year’s resolutions are simply hot air, stated at around 11:55 pm, on a night involving plenty of alcohol. They are rarely respected, and there is no way for them to be enforced. They are a ritual, but not more important than kissing a loved one 5 minutes later.

Beyond theory, what about empirics? Let me report the results of an informal poll around our holiday table: none of the men (out of 3) and 2 of the women (out of 4) typically make New Year’s resolutions, and only one person actually expects to keep her resolutions. Is this typical?

Do you make New Year’s resolutions? Why or why not? Comments are open.