Elsevier

Journal of Economic Theory

Volume 145, Issue 5, September 2010, Pages 1648-1674
Journal of Economic Theory

Individual versus group strategy-proofness: When do they coincide?

https://doi.org/10.1016/j.jet.2010.03.006Get rights and content

Abstract

A social choice function is group strategy-proof on a domain if no group of agents can manipulate its final outcome to their own benefit by declaring false preferences on that domain. There are a number of economically significant domains where interesting rules satisfying individual strategy-proofness can be defined, and for some of them, all these rules turn out to also satisfy the stronger requirement of group strategy-proofness. We provide conditions on domains guaranteeing that for all rules defined on them, individual and group strategy-proofness become equivalent. We also provide a partial answer regarding the necessity of our conditions.

References (24)

  • K. Border et al.

    Straightforward elections, unanimity and phantom voters

    Rev. Econ. Stud.

    (1983)
  • P. Dasgupta et al.

    The implementation of social choice rules: Some general results on incentive compatibility

    Rev. Econ. Stud.

    (1979)
  • Cited by (74)

    • On the manipulability of equitable voting rules

      2023, Games and Economic Behavior
    • Anonymous, non-manipulable binary social choice

      2022, Games and Economic Behavior
    • Restricted environments and incentive compatibility in interdependent values models

      2022, Games and Economic Behavior
      Citation Excerpt :

      This is an example in which our Theorem 4 also applies, since the universal set of strict preferences is partially knit (see Proposition 2) and dictatorships are ex post group incentive compatible, but we use it here as a warning sign that the implications of Theorem 4, as already explained may or may not be of interest depending on the environments. This result that applies to private values provides a complementary view of our unifying results in Barberà et al. (2010, 2016), because partial knitness is not the same domain condition that those that we invoked there, nor is the proof of equivalence the same. Justifying the use of our conditions on environments is clearly needed, since they are certainly involved and abstract.

    View all citing articles on Scopus

    We are grateful to three anonymous referees and many colleagues for their useful comments in different congresses and workshops where the paper was presented. Salvador Barberà gratefully acknowledges support from the Spanish Ministry of Science and Innovation through grant “Consolidated Group-C” ECO2008-04756, and by the Generalitat de Catalunya, Departament d'Universitats, Recerca i Societat de la Informació through the Distinció per a la Promoció de la Recerca Universitària, grant SGR2009-0419 and the Barcelona GSE Research Network. Dolors Berga acknowledges the support of the Spanish Ministry of Science and Innovation through grant SEJ2007-60671 and of Generalitat de Catalunya, through grant SGR2009-0189. She also acknowledges the Research Recognition Programme of the Barcelona GSE. Bernardo Moreno acknowledges financial support from Junta de Andalucía through Proyecto de Excelencia 522 and the ECO2008-03674 from the Spanish Ministry of Science and Innovation.

    View full text