“A Unique Maximal Domain for Strategy-Proofness without Pareto Efficiency ” by Stephen Ching
The University of Hong Kong
Ching and Serizawa (1998) showed that the single-plateaued domain is the unique maximal domain for strategy-proofness, symmetry,and efficiency, but pointed out that strategy-proofness becomes redundant when symmetry is strengthened to strong symmetry (which is weaker than anonymity), i.e. the single-plateaued domain remains the unique maximal domain for strong symmetry and efficiency. In this paper, efficiency is relaxed to unanimity and continuity. The weakly monotonic single-peaked domain is identified as the unique maximal domain for strategy-proofness, strong symmetry, unanimity, and continuity. Strategy-proofness can no longer be dropped in this result. The tie between strategy-proofness and single-peakedness is restored.