{"type":"ScholarlyArticle","title":"Participatory Budgeting Project Strength via Candidate Control","authors":[{"name":"Piotr Faliszewski","slug":"piotr-faliszewski","given":"Piotr","family":"Faliszewski","affiliation":""},{"name":"Łukasz Janeczko","slug":"ukasz-janeczko","given":"Łukasz","family":"Janeczko","affiliation":""},{"name":"Dušan Knop","slug":"dusan-knop","given":"Dušan","family":"Knop","affiliation":""},{"name":"Jan Pokorný","slug":"jan-pokorny","given":"Jan","family":"Pokorný","affiliation":""},{"name":"Šimon Schierreich","slug":"simon-schierreich","given":"Šimon","family":"Schierreich","affiliation":""},{"name":"Mateusz Słuszniak","slug":"mateusz-s-uszniak","given":"Mateusz","family":"Słuszniak","affiliation":""},{"name":"Krzysztof Sornat","slug":"krzysztof-sornat","given":"Krzysztof","family":"Sornat","affiliation":""}],"abstract":"We study the complexity of candidate control in participatory budgeting elections. The goal of constructive candidate control is to ensure that a given candidate wins by either adding or deleting candidates from the election (in the destructive setting, the goal is to prevent a given candidate from winning). We show that such control problems are NP-hard to solve for many participatory budgeting voting rules, including Phragmén and Equal-Shares, but there are natural cases with polynomial-time algorithms. We also argue that control by deleting candidates is a useful tool for assessing the performance (or, strength) of initially losing projects, and we support this view with experiments on real-life PB instances.","doi":"10.24963/ijcai.2025/425","url":"https://ijcai.org/proceedings/2025/425","pdf":"https://ijcai.org/proceedings/2025/0425.pdf","markdown":"https://ijcai.org/proceedings/2025/425.md","bibtex":"https://ijcai.org/proceedings/2025/bibtex/425","volume":{"slug":"2025","title":"Proceedings of the Thirty-Fourth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2025","url":"https://ijcai.org/proceedings/2025/","year":2025,"location":"Montreal, Canada","dates":"16-22 August 2025","editors":"James Kwok","isbn":"978-1-956792-06-5","publisher":"International Joint Conferences on Artificial Intelligence Organization","doi_prefix":"10.24963/ijcai.2025"},"section":"Game Theory and Economic Paradigms","track":"Main Track","number":425,"pages":{"first":3821,"last":3829},"keywords":["Game Theory and Economic Paradigms: GTEP: Computational social choice"],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}