Informal commitments in planner–doer games

Abstract

This paper studies the role of informal commitments in dynamic choice under self-control. Informal commitments, in contrast to formal commitments, are ad hoc personal rules of behavior that are not always observable. Moreover, the effectiveness of these rules in constraining future choices is often dependent on the decision-maker. We model informal commitments using an extension of a standard planner–doer model, after Thaler and Shefrin (1981). Taking a preference over menus (i.e. formal commitments) as an observable, our main results show how to elicit and partially identify this model. Our model can explain evidence on self-control behavior that cannot be represented by the Gul and Pesendorfer (2001) model of self-control nor by any of its recent extensions.