p.1

Timing and Self-Control

Drew Fudenberg
David K. Levine

Abstract

The standard dual-self model of self-control, with a shorter-run self who cares only about the current period, is excessively sensitive to the timing of decisions and to the interpolation of additional "no-action" time periods in between the dates when decisions are made. We show that when the shorter-run self is not completely myopic, this excess sensitivity goes away. To accommodate the combination of short time periods and convex costs of self-control, we introduce a cognitive resource variable that tracks how the control cost depends on the self-control that has been used in the recent past. We consider models with both linear and convex control costs, illustrating the theory through a series of examples. We examine when opportunities to consume will be avoided or delayed, and we consider the way in which the marginal interest declines with delay.