Template-type: ReDif-Paper 1.0
Author-Name: Dietrich Franz 
Author-Name: List Christian 
Author-workplace-name: METEOR
Title: Judgment aggregation without full rationality
Abstract: Several recent results on the aggregation of judgments over logically connected propositions show that, under certain conditions, dictatorships are the only independent (i.e., propositionwise) aggregation rules 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 (strong) 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.
Keywords: mathematical economics; 
Series: Research Memoranda
Creation-Date: 2006
Number: 032
File-URL: http://digitalarchive.maastrichtuniversity.nl/fedora/objects/guid:653304e7-9784-4a4c-9cc9-80474830cce0/datastreams/ASSET1/content
File-Format: application/pdf
File-Size: 251803
Handle: RePEc:unm:umamet:2006032