On Strategy-proofness and Symmetric Single-Peakedness

• Authors: Inés Moreno de Barreda.
• BSE Working Paper: 421 | September 15
• Keywords: strategy-proofness , Single-peaked preferences , median voter , Feasibility Constraints
• JEL codes: D7
• strategy-proofness
• Single-peaked preferences
• median voter
• Feasibility Constraints

We characterize the class of strategy-proof social choice functions on the domain of symmetric single-peaked preferences. This class is strictly larger than the set of generalized median voter schemes (the class of strategy-proof and tops-only social choice functions on the domain of single peaked preferences characterized by Moulin (1980)) since, under the domain of symmetric single-peaked preferences, generalized median voter schemes can be disturbed by discontinuity points and remain strategy-proof on the smaller domain. Our result identifies the specific nature of these discontinuities which allow to design non-onto social choice functions to deal with feasibility constraints.