Participatory Budgeting Project Strength via Candidate Control
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 Phragm\'en and Method of Equal Shares, but there are natural cases with polynomial-time algorithms (e.g., for the GreedyAV rule and projects with costs encoded in unary). 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.
Cite
@article{arxiv.2601.16511,
title = {Participatory Budgeting Project Strength via Candidate Control},
author = {Piotr Faliszewski and Łukasz Janeczko and Dušan Knop and Jan Pokorný and Šimon Schierreich and Mateusz Słuszniak and Krzysztof Sornat},
journal= {arXiv preprint arXiv:2601.16511},
year = {2026}
}
Comments
A preliminary version appeared in IJCAI '25