Strategy-Proofness and Single-Crossing
Theoretical Economics 4 (2009), 127–163
Posted: 15 Aug 2017
Date Written: November 10, 2007
Abstract
This paper analyzes strategy-proof collective choice rules when individuals have single-crossing preferences on a finite and ordered set of social alternatives. It shows that a social choice rule is anonymous, unanimous, and strategy-proof on a maximal single-crossing domain if and only if it is an extended median rule with n−1 fixed ballots distributed over the individuals’ most preferred alternatives. As a by-product, the paper also proves that strategy-proofness implies the tops-only property. It also offers a strategic foundation for the so-called “single-crossing version” of the Median Voter Theorem, by showing that the median ideal point can be implemented in dominant strategies by a direct mechanism in which every individual reveals his true preferences.
Keywords: Single-Crossing, Strategy-Proofness, Tops-Only, Peak Rules
JEL Classification: C72, D71, D78
Suggested Citation: Suggested Citation