{"type":"ScholarlyArticle","title":"The Condorcet Principle for Multiwinner Elections: From Shortlisting to Proportionality","authors":[{"name":"Haris Aziz","slug":"haris-aziz","given":"Haris","family":"Aziz","affiliation":"UNSW , Sydney , Australia"},{"name":"Edith Elkind","slug":"edith-elkind","given":"Edith","family":"Elkind","affiliation":"University of Oxford , Oxford , UK"},{"name":"Piotr Faliszewski","slug":"piotr-faliszewski","given":"Piotr","family":"Faliszewski","affiliation":"AGH University , Krakow , Poland; Data61 , Sydney , Australia"},{"name":"Martin Lackner","slug":"martin-lackner","given":"Martin","family":"Lackner","affiliation":"University of Oxford , Oxford , UK"},{"name":"Piotr Skowron","slug":"piotr-skowron","given":"Piotr","family":"Skowron","affiliation":"TU Berlin , Berlin , Germany"}],"abstract":"We study two notions of stability in multiwinner elections that are based on the Condorcet criterion. The first notion was introduced by Gehrlein and is majoritarian in spirit. The second one, local stability, is introduced in this paper, and focuses on voter representation.  The goal of this paper is to explore these two notions, their implications on restricted domains, and the computational complexity of rules that are consistent with them.","doi":"10.24963/ijcai.2017/13","url":"https://ijcai.org/proceedings/2017/13","pdf":"https://ijcai.org/proceedings/2017/0013.pdf","markdown":"https://ijcai.org/proceedings/2017/13.md","bibtex":"https://ijcai.org/proceedings/2017/bibtex/13","volume":{"slug":"2017","title":"Proceedings of the Twenty-Sixth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2017","url":"https://ijcai.org/proceedings/2017/","year":2017,"location":"Melbourne, Australia","dates":"19-25 August 2017","editors":"Carles Sierra","isbn":"978-0-9992411-0-3","publisher":"International Joint Conferences on Artificial Intelligence Organization","doi_prefix":"10.24963/ijcai.2017"},"section":"Agent-based and Multi-agent Systems","track":"Main track","number":13,"pages":{"first":84,"last":90},"keywords":["Agent-based and Multi-agent Systems: Social Choice Theory","Agent-based and Multi-agent Systems: Cooperative Games"],"videos":[],"references":[{"position":1,"raw":"[Arrow et al., 2002] K. J. Arrow, A. Sen, and K. Suzumura, editors. Handbook of social choice and welfare, volume 1. Elsevier, 2002.","title":"Handbook of social choice and welfare","authors":null,"year":"2002","venue":null,"doi":null,"url":null,"internal_url":null},{"position":2,"raw":"[Aziz et al., 2017a] H. Aziz, M. Brill, V. Conitzer, E. Elkind, R. Freeman, and T. Walsh. Justified representation in approval-based committee voting. Social Choice and Wel- fare, 48(2):461-485, 2017.","title":"Justified representation in approval-based committee voting","authors":"Aziz","year":"2017","venue":"Social Choice and Welfare","doi":null,"url":null,"internal_url":null},{"position":3,"raw":"[Aziz et al., 2017b] H. Aziz, E. Elkind, P. Faliszewski, M. Lackner, and P. Skowron. The Condorcet principle for multiwinner elections: From shortlisting to proportional- ity. Technical Report arXiv:1701.08023, arXiv.org, 2017.","title":"The Condorcet principle for multiwinner elections: From shortlisting to proportionality","authors":"Aziz","year":"2017","venue":null,"doi":null,"url":null,"internal_url":null},{"position":4,"raw":"[Barberà and Coelho, 2008] S. Barberà and D. Coelho. How to choose a non-controversial list with k names. Social Choice and Welfare, 31(1):79-96, 2008.","title":"How to choose a non-controversial list with k names","authors":"S Barberà, D Coelho","year":"2008","venue":"Social Choice and Welfare","doi":null,"url":null,"internal_url":null},{"position":5,"raw":"[Brandt et al., 2016a] F. Brandt, V. Conitzer, U. Endriss, A. Procaccia, and J. Lang, editors. Handbook of Computa- tional Social Choice. Cambridge University Press, 2016.","title":"Handbook of Computational Social Choice","authors":"Brandt","year":"2016","venue":null,"doi":null,"url":null,"internal_url":null},{"position":6,"raw":"[Brandt et al., 2016b] F. Brandt, C. Geist, and D. Peters. Op- timal bounds for the no-show paradox via SAT solving. In Proceedings of the 15th International Conference on Au- tonomous Agents and Multiagent Systems (AAMAS-2016), pages 314-322, 2016.","title":"Optimal bounds for the no-show paradox via SAT solving","authors":"Brandt","year":"2016","venue":"Proceedings of the 15th International Conference on Autonomous Agents and Multiagent Systems (AAMAS-2016)","doi":null,"url":null,"internal_url":null},{"position":7,"raw":"[Coelho, 2004] D. Coelho. Understanding, evaluating and selecting voting rules through games and axioms. PhD thesis, 2004.","title":"Understanding, evaluating and selecting voting rules through games and axioms","authors":"D Coelho","year":"2004","venue":null,"doi":null,"url":null,"internal_url":null},{"position":8,"raw":"[Darmann, 2013] A. Darmann. How hard is it to tell which is a Condorcet committee? Mathematical Social Sciences, 66(3):282-292, 2013.","title":"How hard is it to tell which is a Condorcet committee?","authors":"A Darmann","year":"2013","venue":"Mathematical Social Sciences","doi":null,"url":null,"internal_url":null},{"position":9,"raw":"[Dwork et al., 2001] C. Dwork, R. Kumar, M. Naor, and D. Sivakumar. Rank aggregation methods for the web. In Proceedings of the 10th International World Wide Web Conference (WWW-2001), pages 613-622, 2001.","title":"Rank aggregation methods for the web","authors":"C Dwork, R Kumar, M Naor, D Sivakumar","year":"2001","venue":"Proceedings of the 10th International World Wide Web Conference (WWW-2001)","doi":null,"url":null,"internal_url":null},{"position":10,"raw":"[Elkind et al., 2015] E. Elkind, J. Lang, and A. Saffidine. Condorcet winning sets. Social Choice and Welfare, 44(3):493-517, 2015.","title":"Condorcet winning sets","authors":"E Elkind, J Lang, A Saffidine","year":"2015","venue":"Social Choice and Welfare","doi":null,"url":null,"internal_url":null},{"position":11,"raw":"[Elkind et al., 2017] E. Elkind, P. Faliszewski, P. Skowron, and A. Slinko. Properties of multiwinner voting rules. So- cial Choice and Welfare, 48(3):599-632, 2017.","title":"Properties of multiwinner voting rules","authors":"E Elkind, P Faliszewski, P Skowron, A Slinko","year":"2017","venue":"Social Choice and Welfare","doi":null,"url":null,"internal_url":null},{"position":12,"raw":"[Fishburn, 1981a] P. Fishburn. Majority committees. Jour- nal of Economic Theory, 25(2):255-268, 1981.","title":"Majority committees","authors":"; P Fishburn, Fishburn","year":"1981","venue":"Journal of Economic Theory","doi":null,"url":null,"internal_url":null},{"position":13,"raw":"[Fishburn, 1981b] P. C. Fishburn. An analysis of simple vot- ing systems for electing committees. SIAM Journal on Applied Mathematics, 41(3):499-502, 1981.","title":"An analysis of simple voting systems for electing committees","authors":"P C Fishburn, Fishburn","year":"1981","venue":"SIAM Journal on Applied Mathematics","doi":null,"url":null,"internal_url":null},{"position":14,"raw":"[Garey and Johnson, 1979] M. Garey and D. Johnson. Com- puters and Intractability: A Guide to the Theory of NP- Completeness. W. H. Freeman and Company, 1979.","title":"Computers and Intractability: A Guide to the Theory of NP-Completeness","authors":"M Garey, D Johnson","year":"1979","venue":null,"doi":null,"url":null,"internal_url":null},{"position":15,"raw":"[Gehrlein, 1985] W. V. Gehrlein. The Condorcet criterion and committee selection. Mathematical Social Sciences, 10(3):199-209, 1985.","title":"The Condorcet criterion and committee selection","authors":"W V Gehrlein","year":"1985","venue":"Mathematical Social Sciences","doi":null,"url":null,"internal_url":null},{"position":16,"raw":"[Johnson and Niemi, 1983] D. S. Johnson and K. A. Niemi. On knapsacks, partitions, and a new dynamic program- ming technique for trees. Mathematics of Operations Re- search, 8(1):1-14, 1983.","title":"On knapsacks, partitions, and a new dynamic programming technique for trees","authors":"D S Johnson, K A Niemi","year":"1983","venue":"Mathematics of Operations Research","doi":null,"url":null,"internal_url":null},{"position":17,"raw":"[Kamwa, 2017a] E. Kamwa. On stable rules for selecting committees. Journal of Mathematical Economics, 70:36- 44, 2017.","title":"On stable rules for selecting committees","authors":"] E Kamwa ; A, Kamwa","year":"2017","venue":"Journal of Mathematical Economics","doi":null,"url":null,"internal_url":null},{"position":18,"raw":"[Kamwa, 2017b] E. Kamwa. Stable rules for electing com- mittees and divergence on outcomes. Group Decision and Negotiation, 26(3):547-564, 2017.","title":"Stable rules for electing committees and divergence on outcomes","authors":"; E Kamwa, Kamwa","year":"2017","venue":"Group Decision and Negotiation","doi":null,"url":null,"internal_url":null},{"position":19,"raw":"[McGarvey, 1953] David C McGarvey. A theorem on the construction of voting paradoxes. Econometrica, 21(4):608-610, 1953.","title":"A theorem on the construction of voting paradoxes","authors":"C David, Mcgarvey","year":"1953","venue":"Econometrica","doi":null,"url":null,"internal_url":null},{"position":20,"raw":"[Mirrlees, 1971] J. Mirrlees. An exploration in the theory of optimal income taxation. Review of Economic Studies, 38:175-208, 1971.","title":"An exploration in the theory of optimal income taxation","authors":"J Mirrlees","year":"1971","venue":"Review of Economic Studies","doi":null,"url":null,"internal_url":null},{"position":21,"raw":"[Moulin, 1988] H. Moulin. Condorcet's principle implies the no show paradox. Journal of Economic Theory, 45:53-64, 1988.","title":"Condorcet's principle implies the no show paradox","authors":"H Moulin","year":"1988","venue":"Journal of Economic Theory","doi":null,"url":null,"internal_url":null},{"position":22,"raw":"[Moulin, 1989] H. Moulin. Axioms of Cooperative Decision Making. Cambridge University Press, 1989.","title":"Axioms of Cooperative Decision Making","authors":"H Moulin","year":"1989","venue":null,"doi":null,"url":null,"internal_url":null},{"position":23,"raw":"[Ratliff, 2003] T. C. Ratliff. Some startling inconsistencies when electing committees. Social Choice and Welfare, 21(3):433-454, 2003.","title":"Some startling inconsistencies when electing committees","authors":"T C Ratliff","year":"2003","venue":"Social Choice and Welfare","doi":null,"url":null,"internal_url":null},{"position":24,"raw":"[Roberts, 1977] K. W. S. Roberts. Voting over income tax schedules. Journal of Public Economics, 8(3):329-340, 1977.","title":"Voting over income tax schedules","authors":"K W S Roberts","year":"1977","venue":"Journal of Public Economics","doi":null,"url":null,"internal_url":null},{"position":25,"raw":"[Rothstein, 1991] P. Rothstein. Representative voter theo- rems. Public Choice, 72(2):193-212, 1991.","title":"Representative voter theorems","authors":"P Rothstein","year":"1991","venue":"Public Choice","doi":null,"url":null,"internal_url":null},{"position":26,"raw":"[Saporiti and Tohmé, 2006] A. Saporiti and F. Tohmé. Single-crossing, strategic voting and the median choice rule. Social Choice and Welfare, 26(2):363-383, 2006.","title":"Single-crossing, strategic voting and the median choice rule","authors":"A Saporiti, F Tohmé","year":"2006","venue":"Social Choice and Welfare","doi":null,"url":null,"internal_url":null},{"position":27,"raw":"[Sekar et al., 2017] S. Sekar, S. Sikdar, and L. Xia. Con- dorcet consistent bundling with social choice. In Proceed- ings of the 16th International Conference on Autonomous Agents and Multiagent Systems (AAMAS-2017), pages 33- 41, 2017.","title":"Condorcet consistent bundling with social choice","authors":"S Sekar, S Sikdar, L Xia","year":"2017","venue":"Proceedings of the 16th International Conference on Autonomous Agents and Multiagent Systems (AAMAS-2017)","doi":null,"url":null,"internal_url":null},{"position":28,"raw":"[Skowron et al., 2016] P. Skowron, P. Faliszewski, and J. Lang. Finding a collective set of items: From propor- tional multirepresentation to group recommendation. Ar- tificial Intelligence, 241:191-216, 2016.","title":"Finding a collective set of items: From proportional multirepresentation to group recommendation","authors":"P Skowron, P Faliszewski, J Lang","year":"2016","venue":"Artificial Intelligence","doi":null,"url":null,"internal_url":null}],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}