The instability of robust aggregation

Matthias Hild ()

Social Choice and Welfare, 2004, vol. 23, issue 2, 207-227

Abstract: Levi’s ‘robust aggregation’ suggests a generalization of the standard ‘ex ante’ mode of aggregating individuals’ expected utilities into a social choice function. This generalization applies some social choice rule not only to the actual individuals but also to hypothetical individuals with all possible combinations of the actual individuals’ probabilities and utilities. We show that robust aggregation can lead to preference reversals in the social choice when the very same decision situation is described with different degrees of detail, thus violating a desirable stability condition. We also show that any stable robust social choice rule must collapse back into the ex ante mode without recourse to hypothetical individuals. Under sufficient conditions, such as strong Pareto optimality, robust aggregation even leads to an infinite series of reversals in group choices. By contrast, stability is ubiquitous in the standard ex ante mode and is closely related to independence of irrelevant alternatives. Copyright Springer-Verlag 2004

Date: 2004
References: Add references at CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
http://hdl.handle.net/10.1007/s00355-003-0248-4 (text/html)
Access to full text is restricted to subscribers.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:spr:sochwe:v:23:y:2004:i:2:p:207-227

Ordering information: This journal article can be ordered from
http://www.springer. ... c+theory/journal/355

DOI: 10.1007/s00355-003-0248-4

Access Statistics for this article

Social Choice and Welfare is currently edited by Bhaskar Dutta, Marc Fleurbaey, Elizabeth Maggie Penn and Clemens Puppe

More articles in Social Choice and Welfare from Springer, The Society for Social Choice and Welfare Contact information at EDIRC.
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().