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Majority judgment and strategy-proofness: a characterization

  • Stefano VannucciEmail author
Original Paper
  • 22 Downloads

Abstract

Majority judgment as recently formulated and advocated by Balinski and Laraki in their influential monograph (Majority Judgment (2010)) is a method to aggregate profiles of judgments which are expressed in a common language consisting of a linearly ordered, and typically bounded, set of grades. It is shown that majority judgment thus defined is strategy-proof but not coalitionally strategy-proof on a very comprehensive class of rich single peaked preference domains. The proof relies on the key observation that a common bounded linear order of grades makes the set of gradings a product of bounded chains, which is a special instance of a bounded distributive lattice. Relying on the foregoing result, this paper also provides a simple characterization of majority judgment with an odd number of agents by anonymity, bi-idempotence and strategy-proofness on rich single peaked domains.

Keywords

Strategy-proofness Bounded distributive lattice Single peakedness Majority rule Majority judgment 

Mathematics Subject Classification

05C05 52021 52037 

JEL Classification

D71 

Notes

Acknowledgements

Thanks are due to two anonymous reviewers and an Associate Editor for their careful reading of the paper, and their most focussed, helpful and constructive criticisms.

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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Economics and StatisticsUniversity of SienaSienaItaly

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