Collective Rationality

Abstract

A theory of collective rationality identifies collective acts that are evaluable for rationality and formulates principles for their evaluation. This book argues that a group's act is evaluable for rationality if it is the product of acts its members freely and fully control. It also argues that such an act is collectively rational if the acts of the group's members are rational. Efficiency is a goal of collective rationality, but not a requirement, except in cases where conditions are ideal for joint action and agents have rationally prepared for coordination. A theory of collective rationality also yields principles concerning solutions to games. One principle requires that a solution constitute an equilibrium among the incentives of the agents in the game. In a cooperative game some agents are coalitions of individuals, and it may be impossible for all agents to pursue all incentives. Because rationality is attainable, the appropriate equilibrium‐standard for cooperative games requires pursuit of an incentive only if it provides a sufficient reason to act. The book's theory of collective rationality supports an attainable equilibrium‐standard for solutions to cooperative games and shows that its realization follows from individuals' rational acts. This book's theory of collective rationality contributes to philosophical projects such as contractarian ethics and to practical projects such as the design of social institutions.