Overlapping Generations and Environmental Policy: An Introduction

A small but growing body of literature uses overlapping generations (OLG) models to study environmental policy for long-lived problems such as climate change. An OLG model, unlike the infinitely lived representative agent model, distinguishes between impatience with respect to one’s own future utility, and attitudes toward successors’ utility. I discuss the problem of time inconsistency, the role of Markov perfection, and show that a class of OLG models can be studied using methods developed to analyze models of non-constant discounting. An example illustrates the techniques and determines the conditions under which, in equilibrium, there is under-investment or over-investment in natural capital.