Advanced Textbooks in Economics, Volume 18: The Strategy of Social Choice focuses on the social, economics, and political implications of social choice. The publication first surveys introduction, social choice functions and correspondences, and monotonicity and the arrow theorem. Discussions focus on efficiency, anonymity and neutrality, classifying voting methods, normative versus positive approach to voting, voting and the non-strategic theory of social choice, and development of the strategic theory of voting. The text then ponders on strategy-proofness and monotonicity and sophisticated voting. Topics include sophisticated implementation, voting by binary choices, strategy-proof social choice functions and game forms, Gibbard-Satterthwaite theorem, and restricted domains. The manuscript examines cooperative voting and voting by veto, including the minority principle, proportional veto core, voting by integer veto, effectivity functions, maximal and stable effectivity functions, and implementation by Nash equilibrium. The text is a dependable source of data for researchers interested in the process of social choice.

This book was written mainly during the Spring periods of 2008 and 2009, when the ?rst author was visiting Maastricht University. Financial s- port both from the Dutch Science Foundation NWO (grants 040. 11. 013 and 0. 40. 11. 082) and from the research institute METEOR (Maastricht Univ- sity) is gratefully acknowledged. Jerusalem Bezalel Peleg Maastricht Hans Peters April 2010 v Contents Preview to this book . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi Part I Representations of constitutions 1 Introduction to Part I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. 1 Motivation and summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. 2 Arrow’s constitution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. 3 Arrow’s Impossibility Theorem and its implications. . . . . . . . . 4 1. 4 Ga ̈rdenfors’s model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 5 Notes and comments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2 Constitutions, e?ectivity functions, and game forms . . . . . . 7 2. 1 Motivation and summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2. 2 Constitutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2. 3 Constitutions and e?ectivity functions . . . . . . . . . . . . . . . . . . . . 12 2. 4 Game forms and a representation theorem. . . . . . . . . . . . . . . . . 16 2. 5 Representation and simultaneous exercising of rights. . . . . . . . 19 2. 6 Notes and comments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3 Nash consistent representations. . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3. 1 Motivation and summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3. 2 Existence of Nash consistent representations: a general result 22 3. 3 The case of ?nitely many alternatives. . . . . . . . . . . . . . . . . . . . . 24 3. 4 Nash consistent representations of topological e?ectivity functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 3. 5 Veto functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 3. 5. 1 Finitely many alternatives. . . . . . . . . . . . . . . . . . . . . . . . . 34 3. 5. 2 Topological veto functions. . . . . . . . . . . . . . . . . . . . . . . . . 36 3. 6 Liberalism and Pareto optimality of Nash equilibria. . . . . . . . . 40 3. 7 Notes and comments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 vii viii Contents 4 Acceptable representations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 4. 1 Motivation and summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

This second part of a two-volume set continues to describe economists' efforts to quantify the social decisions people necessarily make and the philosophies that those choices define. Contributors draw on lessons from philosophy, history, and other disciplines, but they ultimately use editor Kenneth Arrow's seminal work on social choice as a jumping-off point for discussing ways to incentivize, punish, and distribute goods. - Develops many subjects from Volume 1 (2002) while introducing new themes in welfare economics and social choice theory - Features four sections: Foundations, Developments of the Basic Arrovian Schemes, Fairness and Rights, and Voting and Manipulation - Appeals to readers who seek introductions to writings on human well-being and collective decision-making - Presents a spectrum of material, from initial insights and basic functions to important variations on basic schemes

Since World War II the subject of social choice has grown in many and surprising ways. The impossibility theorems have suggested many directions: mathematical characterisations of voting structures satisfying various sets of conditions, the consequences of restricting choice to certain domaines, the relation to competitive equilibrium and the core, and trade-offs among the partial satisfactions of some conditions. The links with classical and modern theories of justice and, in particular, the competing ideas of rights and utilitarianism have shown the power of formal social choice analysis in illuminating the most basic philosophical arguments about the good social life. Finally, the ideals of the just society meet with the play of self interest; social choice mechanisms can lend themselves to manipulation, and the analysis of conditions under which given ideals can be realised under self interest is a political parallel to the welfare economics of the market. The contributors to these volumes focus on these issues at the forefront of current research.

First published in 1971, Social Choice is both a text and reference containing the proceedings of a conference dealing with contemporary work on the normative and descriptive aspects of the social choice problem. This reissue will be of interest to advanced undergraduate and graduate courses on group decision making and social choice. Economists, social psychologists, political scientists and sociologists will welcome this valuable work.

This book offers a comprehensive analysis of the social choice literature and shows, by applying fuzzy sets, how the use of fuzzy preferences, rather than that of strict ones, may affect the social choice theorems. To do this, the book explores the presupposition of rationality within the fuzzy framework and shows that the two conditions for rationality, completeness and transitivity, do exist with fuzzy preferences. Specifically, this book examines: the conditions under which a maximal set exists; the Arrow’s theorem; the Gibbard-Satterthwaite theorem and the median voter theorem. After showing that a non-empty maximal set does exists for fuzzy preference relations, this book goes on to demonstrating the existence of a fuzzy aggregation rule satisfying all five Arrowian conditions, including non-dictatorship. While the Gibbard-Satterthwaite theorem only considers individual fuzzy preferences, this work shows that both individuals and groups can choose alternatives to various degrees, resulting in a social choice that can be both strategy-proof and non-dictatorial. Moreover, the median voter theorem is shown to hold under strict fuzzy preferences but not under weak fuzzy preferences. By providing a standard model of fuzzy social choice and by drawing the necessary connections between the major theorems, this book fills an important gap in the current literature and encourages future empirical research in the field.

Using the economic approach of social choice theory, this unique book examines difficulties found in democratic processes involved in the creation and implementation of planning policies. Social choice theory focuses on the hard trade-offs to be made between rationality in decision-making on the one hand, and political values such as democracy, liberalism and freedom from manipulation on the other. As an institution can be seen as a set of rules, the focus on rules and procedures of collective choice makes social choice theory well suited for analysing important political aspects of planning institutions. Special attention is given to communicative planning and the logical reasons why all the desirable properties of dialogue cannot be simultaneously attained. The analysis provides original and significant new insights into the process and the institutions involved. It highlights weak spots of present planning techniques and procedures and suggests further steps towards institutionally enriched planning theory.

A comprehensive survey of computational aspects of collective decisions for graduate students, researchers, and professionals in computer science and economics.

This book illuminates the sources and consequences of cycles and instability in the mathematical theory of voting and social choice.

The present book treats a highly specialized topic, namely effec tivity functions, which are a tool for describing the power structure implicit in social choice situations of various kind. One of the ad vantages of effectivity functions is that they seem to contain exactly the information which is needed in several problems of implementa tion, that is in designing the rules for individual behaviour given that this behaviour at equilibrium should result in a prescribed functional connection between preferences and outcome. We shall be interested in both formal properties of effectiv ity functions and applications of them in social choice theory, and among such applications in particular the implementation problem. This choice of emphasis necessarily means that some other topics are treated only superficially or not at all. We do not attempt to cover all contributions to the field, rather we try to put some of the results together in order to get a reasonably coherent theory about the role of the power structure in cooperative implementation. The authors are indebted to many persons for assistance and advice during the work on this book. In particular, we would like to thank Peter Fristrup and Bodil Hansen for critical reading of the manuscript, and Lene Petersen for typesetting in '.lEX.