Judgement aggregation without full rationality

Franz Dietrich, Christian List

Research output: Contribution to journalArticlepeer-review

64 Citations (Scopus)

Abstract

Several recent results on the aggregation of judgments over logically connected propositions show that, under certain conditions, dictatorships are the only propositionwise aggregation functions generating fully rational (i.e., complete and consistent) collective judgments. A frequently mentioned route to avoid dictatorships is to allow incomplete collective judgments. We show that this route does not lead very far: we obtain oligarchies rather than dictatorships if instead of full rationality we merely require that collective judgments be deductively closed, arguably a minimal condition of rationality, compatible even with empty judgment sets. We derive several characterizations of oligarchies and provide illustrative applications to Arrowian preference aggregation and Kasher and Rubinstein’s group identification problem.
Original languageEnglish
Pages (from-to)15-39
Number of pages25
JournalSocial Choice and Welfare
Volume31
Issue number1
DOIs
Publication statusPublished - Jun 2008

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