Human utility embodies a number of seemingly irrational aspects. The leading example in this paper is that utilities often depend on the presence of salient unchosen alternatives. Our focus is to understand <i>why</i> an evolutionary process might optimally lead to such seemingly dysfunctional features...

In this paper we study the optimal forest conservation policy by a hyperbolically discounting society. Society comprises a series of non-overlapping imperfectly altruistic generations each represented by its own government. Under uncertainty about future pay-offs we determine, as solution of an...

Self-administered rewards are ubiquitous. They serve as incentives for personal accomplish¬ments and are widely recommended as tools for overcoming self-control problems. However, it seems puzzling why self-rewards can work: the prospect of a reward has a motivating force only if the threat of...

In this paper, we develop a revealed preference methodology that allows us to explore whether time inconsistencies in household choice are the product of individual preference nonstationarities or the result of individual heterogeneity and renegotiation within the collective unit. An empirical...

We investigate necessary and sufficient nonparametric conditions for the quasi-hyperbolic consumer. These turn out to be quite tractable. We investigate the performance of this model compared to the standard exponential discounting model using consumer panel data.

How does the need to preserve government debt sustainability affect the optimal monetary and fiscal policy response to a liquidity trap? To provide an answer, we employ a small stochastic New Keynesian model with a zero bound on nominal interest rates and characterize optimal time-consistent...

I examine the circumstances under which a sophisticated time-inconsistent decisionmaker (i) will not or (ii) need not severely miscoordinate her behavior across time, in the sense of following a course of action which fails to be Pareto-optimal for the sequence of temporal selves of the...

We study collective decisions by time-discounting individuals choosing a common consumption stream. We show that with any heterogeneity in time preferences, utilitarian aggregation necessitates a present bias. In lab experiments three quarters of `social planners' exhibited present biases, and...

This paper provides a revealed preference characterisation of quasi-hyperbolic discounting which is designed to be applied to readily-available expenditure surveys. We describe necessary and sufficient conditions for the leading forms of the model and also study the consequences of the...

We prove that the standard quasi-geometric discounting model used in dynamic consumer theory and political economics does not possess continuous Markov perfect equilibria (MPE) if there is a strictly positive lower bound on wealth. We also show that, at points of discontinuity, the decision...