Stefano Vannucci
DEPS, Università di Siena
Abstract
Majority judgment as recently formulated and advocated by Balinski and Laraki in their influential monograph (Majority Judgment (2010)) is a method to aggregate profi les of judgments which are expressed in a common language consisting of a bounded linearly ordered set of grades. It is shown that majority judgment is strategy-proof but not coalitionally strategy-proof on a very comprehensive class of rich single peaked preference domains. The proof relies on the key observation that a common bounded linear order of grades makes the set of gradings a product of bounded chains, which is a special instance of a bounded distributive lattice. As a by-product, we also obtain a characterization of majority judgment with an odd number of agents by anonymity, bi-idempotence and strategy-proofness on rich single peaked domains.
Keywords
Strategy-proofness, bounded distributive lattice, single peakedness, majority rule, majority judgment
Jel Codes
D71
