{"type":"ScholarlyArticle","title":"An Experimental View on Committees Providing Justified Representation","authors":[{"name":"Robert Bredereck","slug":"robert-bredereck","given":"Robert","family":"Bredereck","affiliation":"TU Berlin , Berlin , Germany"},{"name":"Piotr Faliszewski","slug":"piotr-faliszewski","given":"Piotr","family":"Faliszewski","affiliation":"AGH University , Kraków , Poland"},{"name":"Andrzej Kaczmarczyk","slug":"andrzej-kaczmarczyk","given":"Andrzej","family":"Kaczmarczyk","affiliation":"TU Berlin , Berlin , Germany"},{"name":"Rolf Niedermeier","slug":"rolf-niedermeier","given":"Rolf","family":"Niedermeier","affiliation":"TU Berlin , Berlin , Germany"}],"abstract":"We provide an experimental study of committees that achieve (proportional/extended) justified representation (JR/PJR/EJR). In particular, we ask how many such committees exist and how varied they are in terms of voter satisfaction and coverage.  We find that under many natural distributions of preferences a large fraction of randomly selected JR committees also provide PJR and EJR.  Further, we find that the sets of JR committees for our elections are very varied and include both high-quality ones and not-so-appealing ones.","doi":"10.24963/ijcai.2019/16","url":"https://ijcai.org/proceedings/2019/16","pdf":"https://ijcai.org/proceedings/2019/0016.pdf","markdown":"https://ijcai.org/proceedings/2019/16.md","bibtex":"https://ijcai.org/proceedings/2019/bibtex/16","volume":{"slug":"2019","title":"Proceedings of the Twenty-Eighth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2019","url":"https://ijcai.org/proceedings/2019/","year":2019,"location":"Macao","dates":"10-16 August 2019","editors":"Sarit Kraus","isbn":"978-0-9992411-4-1","publisher":"International Joint Conferences on Artificial Intelligence Organization","doi_prefix":"10.24963/ijcai.2019"},"section":"Agent-based and Multi-agent Systems","track":"Main track","number":16,"pages":{"first":109,"last":115},"keywords":["Agent-based and Multi-agent Systems: Computational Social Choice","Agent-based and Multi-agent Systems: Voting"],"videos":[],"references":[{"position":1,"raw":"[Aziz et al., 2015] Haris Aziz, Serge Gaspers, Joachim Gud- mundsson, Simon Mackenzie, Nicholas Mattei, and Toby Walsh. 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