Preference aggregation theory without acyclicity: The core without majority dissatisfaction

Kumabe, Masahiro and Mihara, H. Reiju (2010): Preference aggregation theory without acyclicity: The core without majority dissatisfaction. Forthcoming in: Games and Economic Behavior

Abstract

Acyclicity of individual preferences is a minimal assumption in social choice theory. We replace that assumption by the direct assumption that preferences have maximal elements on a fixed agenda. We show that the core of a simple game is nonempty for all profiles of such preferences if and only if the number of alternatives in the agenda is less than the Nakamura number of the game. The same is true if we replace the core by the core without majority dissatisfaction, obtained by deleting from the agenda all the alternatives that are non-maximal for all players in a winning coalition. Unlike the core, the core without majority dissatisfaction depends only onthe players' sets of maximal elements and is included in the union of such sets. A result for an extended framework gives another sense in which the core without majority dissatisfaction behaves better than the core.

• Item Type: MPRA Paper
• Language: English
• Keywords: Core; Nakamura number; kappa number; simple games; voting games; maximal elements; acyclic preferences; limit ordinals
• Subjects: D - Microeconomics > D7 - Analysis of Collective Decision-Making > D71 - Social Choice ; Clubs ; Committees ; Associations; C - Mathematical and Quantitative Methods > C7 - Game Theory and Bargaining Theory > C71 - Cooperative Games; C - Mathematical and Quantitative Methods > C0 - General > C02 - Mathematical Methods

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