Strategy-proofness on the Non-Paretian Subdomain

TL;DR

This paper proves that any strategy-proof voting rule on a specific non-Pareto-dominance domain with at least three options must be dictatorial, extending classical results in social choice theory.

Contribution

It establishes a new characterization of strategy-proof rules on the non-Paretian subdomain, showing they are dictatorial if they include three or more alternatives.

Findings

Strategy-proof rules on NP with ≥3 alternatives are dictatorial.

The result extends Gibbard-Satterthwaite theorem to a restricted domain.

The paper clarifies the structure of strategy-proof social choice functions on NP.

Abstract

Let g be a strategy-proof rule on the domain NP of profiles where no alternative Pareto-dominates any other. Then we establish a result with a Gibbard-Satterthwaite flavor: g is dictatorial if its range contains at least three alternatives.