9 - The Tragedy of the Commons as a Voting Game

Summary

9.1 Introduction

Tragedies of the Commons are often associated with n-person Prisoner's Dilemmas. This is indeed in line with Garrett Hardin's presentation of the story of the herdsmen whose cattle overgraze a commons in his seminal article “The Tragedy of the Commons” (1968) and Robyn Dawes's analysis of this story (1975). Bryan Skyrms (2001) argues that public goods problems often have the structure of n-person Assurance Games whereas Hugh Ward and Michael Taylor (1982) and Taylor (1987, 1990) argue that they often have the structure of n-person Games of Chicken. These three games can also be found as models of public goods problems in Dixit and Skeath (1999: 362–367). Elinor Ostrom (1990: 2–3) reminds us that the Tragedy of the Commons has a long history that predates Hardin starting with Aristotle's Politics. I will present three classical Tragedies of the Commons presented in Aristotle, Mahanarayan, who is narrating a little known sixteenth-century Indian source, and Hume. These classical authors include four types of explanations of why tragedies ensue in their stories, viz. the Expectation-of-Sufficient-Cooperation Explanation, The Too-Many-Players Explanation, the Lack-of-Trust Explanation, and the Private-Benefits Explanation. I present the Voting Game as a model for public goods problems, discuss its history, and show that these explanations as well as the stories themselves align more closely with Voting Games than with Prisoner's Dilemmas, Games of Chicken, and Assurance Games.

9.2 The Tragedy of the Commons and the n-person Prisoner's Dilemma

Hardin (1968) argues that, just like herdsmen add cattle to a commons up to the point that is beyond its carrying capacity, the human population is expanding beyond the earth's carrying capacity. In both cases, there is an individual benefit in adding one animal or one human offspring, but the costs to the collective exceed the benefits to the individual:

The tragedy of the commons develops in this way. […]