Decomposability and strategy-proofness in multidimensional models

• Main Authors: CHATTERJI, Shurojit, ZENG, Huaxia
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2023
• Subjects: Decomposability; strategy-proofness; Economic Theory
• Online Access: https://ink.library.smu.edu.sg/soe_research/2723; https://ink.library.smu.edu.sg/context/soe_research/article/3722/viewcontent/2303.10889_wp.pdf
• Institution: Singapore Management University

We introduce the notion of a multidimensional hybrid preference domain on a (finite) set of alternatives that is a Cartesian product of finitely many components. We demonstrate that in a model of public goods provision, multidimensional hybrid preferences arise naturally through assembling marginal preferences under the condition of semi-separability - a weakening of separability. The main result shows that under a suitable “richness” condition, every strategy-proof rule on this domain can be decomposed into component-wise strategy-proof rules, and more importantly every domain of preferences that reconciles decomposability of rules with strategy-proofness must be a multidimensional hybrid domain.