One of the main challenges facing contemporary society is to understand how people can make decisions together. Understanding Collective Decision Making builds on evolutionary theories and presents an analytical tool to analyse and visualise collective decision making. By combining theoretical research with real world case studies, the authors provide a coherent and conclusive solution to the often fragmented and dispersed literature on the subject.

The Origins of Collective Decision Making, identifies three paradigms of collective decision making – Counsel, Majority and Consensus, and discovers their origins in traditional, medieval and modern times, and traces their evolution over centuries up to the current juncture.

This study is a result of three continuous years of fieldwork in a hamlet in rural Japan. The data presented and analyzed here consist of records from participant observation, formal and informal interviews, casual conversation and formal questionnaires, and public and private documents. The subject of this research is group decision making, and the results of this process are, after all, a matter of public record. The major conclusions of this study are outlined in their simplest and most straightforward form. A hamlet is fundamentally a nexus for the organization of productive exchange among member households, the form of exchange through which two or more parties actively combine their resources to produce something of value not available, or as cheaply available, to any of them separately. Defection from productive exchange agreements by hamlet members is reduced by making access to future valuable transactions and corporate property contingent upon the integrity of each current exchange transaction. This method of combining a common interest in production with contingent access to productive resources is termed mutual investment and is the major source of consensus in hamlet decision making. When only cooperate resources are at issue, decisions regularly result in unanimity. When a course of action can be implemented only if hamlet members relinquish control over individually held resources, a division will emerge among the membership. Whether or not a formal vote is taken, the distribution of differing opinion will be known through more informal means of communication. In all cases of division, by the time the course of action to be implemented is formally announced, the minority in opposition will be extremely small. The question then must be resolved whether those in the minority will participate in the implementation or resign as hamlet members. This book is written with two rather disparate audiences in mind: readers interested primarily in exchange and decision-making phenomenon, on the one hand, and readers interested primarily in the unity of experience represented by the Japanese sensibility, on the other.

Harrie de Swart is a Dutch logician and mathematician with a great and open int- est in applications of logic. After being confronted with Arrow’s Theorem, Harrie became very interested in social choice theory. In 1986 he took the initiative to start up a group of Dutch scientists for the study of social choice theory. This initiative grew out to a research group and a series of colloquia, which were held approximately every month at the University of Tilburg in The Netherlands. The organization of the colloquia was in the hands of Harrie and under his guidance they became more and more internationally known. Many international scholars liked visiting the social choice colloquia in Tilburg and enjoyed giving one or more presentations about their work. They liked Harrie’s kindness and hospitality, and the openness of the group for anything and everything in the eld of social choice. The Social Choice Theory Group started up by Harrie consisted, and still c- sists, of scholars from several disciplines; mostly economics, mathematics, and (mathematical) psychology. It was set up for the study of and discussion about anything that had to do with social choice theory including, and not in the least, the supervision of PhD students in the theory. Members of the group were, among o- ers, Thom Bezembinder (psychologist), Hans Peters (mathematician), Pieter Ruys (economist), Stef Tijs (mathematician and game theorist) and, of course, Harrie de Swart (logician and mathematician).

This encyclopedia provides a premier reference guide for students, scholars, policy makers, and others interested in assessing the moral consequences of global interdependence and understanding the concepts and arguments that shed light on the myriad aspects of global justice.

In the last decade the techniques of social choice theory, game theory and positive political theory have been combined in interesting ways so as to pro vide a common framework for analyzing the behavior of a developed political economy. Social choice theory itself grew out of the innovative attempts by Ken neth Arrow (1951) and Duncan Black (1948, 1958) to extend the range of economic theory in order to deal with collective decision-making over public goods. Later work, by William Baumol (1952), and James Buchanan and Gordon Tullock (1962), focussed on providing an "economic" interpretation of democratic institutions. In the same period Anthony Downs (1957) sought to model representative democracy and elections while William Riker (1962) made use of work in cooperative game theory (by John von Neumann and Oscar Morgenstern, 1944) to study coalition behavior. In my view, these "rational choice" analyses of collective decision-making have their antecedents in the arguments of Adam Smith (1759, 1776), James Madison (1787) and the Marquis de Condorcet (1785) about the "design" of political institutions. In the introductory chapter to this volume I briefly describe how some of the current normative and positive aspects of social choice date back to these earlier writers.

Voting is often the most public and visible example of mass collective decision-making. But how do we define a collective decision? And how do we classify and evaluate the modes by which collective decisions are made? This book examines these crucial ques