Precise Complexity of the Core in Dichotomous and Additive Hedonic Games

Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 10576)

Abstract

Hedonic games provide a general model of coalition formation, in which a set of agents is partitioned into coalitions, with each agent having preferences over which other players are in her coalition. We prove that with additively separable preferences, it is \(\varSigma _2^p\)-complete to decide whether a core- or strict-core-stable partition exists, extending a result of Woeginger (2013). Our result holds even if valuations are symmetric and non-zero only for a constant number of other agents. We also establish \(\varSigma _2^p\)-completeness of deciding non-emptiness of the strict core for hedonic games with dichotomous preferences. Such results establish that the core is much less tractable than solution concepts such as individual stability.

Notes

Acknowledgements

I thank the anonymous reviewers for helpful feedback that improved the clarity of presentation, and Lena Schend for useful discussions. I am supported by EPSRC, by ERC under grant number 639945 (ACCORD), and by COST Action IC1205.

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Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  1. 1.Department of Computer ScienceUniversity of OxfordOxfordUK

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