{"type":"ScholarlyArticle","title":"Determining Winners in Elections with Absent Votes","authors":[{"name":"Qishen Han","slug":"qishen-han","given":"Qishen","family":"Han","affiliation":"Rensselaer Polytechnic Institute"},{"name":"Amelie Marian","slug":"amelie-marian","given":"Amelie","family":"Marian","affiliation":"Rutgers University"},{"name":"Lirong Xia","slug":"lirong-xia","given":"Lirong","family":"Xia","affiliation":"Rensselaer Polytechnic Institute"}],"abstract":"An important question in elections is determining whether a candidate can be a winner when some votes are absent. We study this determining winner with absent votes (WAV) problem with elections that take top-truncated ballots. We show that the WAV problem is NP-complete for single transferable vote, Maximin, and Copeland, and propose a special case of positional scoring rule such that the problem can be computed in polynomial time. Our results for top-truncated rankings differ from the results in full rankings as their hardness results still hold when the number of candidates or the number of missing votes are bounded, while we show that the problem can be solved in polynomial time in either case.","doi":"10.24963/ijcai.2024/312","url":"https://ijcai.org/proceedings/2024/312","pdf":"https://ijcai.org/proceedings/2024/0312.pdf","markdown":"https://ijcai.org/proceedings/2024/312.md","bibtex":"https://ijcai.org/proceedings/2024/bibtex/312","volume":{"slug":"2024","title":"Proceedings of the Thirty-Third International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2024","url":"https://ijcai.org/proceedings/2024/","year":2024,"location":"Jeju, Korea","dates":"3-9 August 2024","editors":"Kate Larson","isbn":"978-1-956792-04-1","publisher":"International Joint Conferences on Artificial Intelligence Organization","doi_prefix":"10.24963/ijcai.2024"},"section":"Game Theory and Economic Paradigms","track":"Main Track","number":312,"pages":{"first":2816,"last":2824},"keywords":["Game Theory and Economic Paradigms: GTEP: Computational social choice"],"videos":[],"references":[{"position":1,"raw":"[Ayadi et al., 2019] Manel Ayadi, Nahla Ben Amor, Jérôme Lang, and Dominik Peters. 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