Hyperbolic Discounting

James Surowiecki reviews The Thief of Time, a book about procrastination, in The New Yorker.

The essence of procrastination lies in not doing what you think you should be doing, a mental contortion that surely accounts for the great psychic toll the habit takes on people. This is the perplexing thing about procrastination: although it seems to involve avoiding unpleasant tasks, indulging in it generally doesn’t make people happy...

Most of the contributors to the new book agree that this peculiar irrationality stems from our relationship to time - in particular, from a tendency that economists call "hyperbolic discounting." A two-stage experiment provides a classic illustration: In the first stage, people are offered the choice between a hundred dollars today or a hundred and ten dollars tomorrow; in the second stage, they choose between a hundred dollars a month from now or a hundred and ten dollars a month and a day from now. In substance, the two choices are identical: wait an extra day, get an extra ten bucks. Yet, in the first stage many people choose to take the smaller sum immediately, whereas in the second they prefer to wait one more day and get the extra ten bucks. In other words, hyperbolic discounters are able to make the rational choice when they’re thinking about the future, but, as the present gets closer, short-term considerations overwhelm their long-term goals. A similar phenomenon is at work in an experiment run by a group including the economist George Loewenstein, in which people were asked to pick one movie to watch that night and one to watch at a later date. Not surprisingly, for the movie they wanted to watch immediately, people tended to pick lowbrow comedies and blockbusters, but when asked what movie they wanted to watch later they were more likely to pick serious, important films. The problem, of course, is that when the time comes to watch the serious movie, another frothy one will often seem more appealing...

The lesson of these experiments is not that people are shortsighted or shallow but that their preferences aren’t consistent over time. We want to watch the Bergman masterpiece, to give ourselves enough time to write the report properly, to set aside money for retirement. But our desires shift as the long run becomes the short run.

You'll be pleased to discover this post contains no joke about how long it took me to cite this article.