Set-rationalizable choice and self-stability

Journal article

Rationalizability and similar notions of consistency have proved to be highly problematic in the context of social choice, as witnessed by a range of impossibility results, among which Arrow's is the most prominent. We propose to rationalize choice functions by preference relations over sets of alternatives (set-rationalizability ) and introduce two consistency conditions, which are defined in analogy to Sen's α and γ. We find that a choice function satisfies one of these conditions if and only if it is set-rationalizable and that it satisfies both if and only if it is self-stable, a new concept based on earlier work by Dutta. The class of self-stable social choice functions contains a number of appealing Condorcet extensions.

Authors: Brandt, F; Harrenstein, B

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Journal of Economic Theory
• Volume: 146
• Issue: 4
• Pages: 1721-1731
• Publication date: 2011-07-01
• DOI: 10.1016/j.jet.2011.03.006
• ISSN: 0022-0531
• Keywords: Stable Sets; Consistency; Social Choice Theory; Rationalizability; Choice Theory