---
title: "Participatory Budgeting with Project Groups"
authors:
  - "Pallavi Jain"
  - "Krzysztof Sornat"
  - "Nimrod Talmon"
  - "Meirav Zehavi"
doi: "10.24963/ijcai.2021/39"
url: "https://ijcai.org/proceedings/2021/39"
pdf: "https://ijcai.org/proceedings/2021/0039.pdf"
venue: "Proceedings of the Thirtieth International Joint Conference on Artificial Intelligence"
year: 2021
pages: "276-282"
track: "Main Track"
keywords:
  - "Agent-based and Multi-agent Systems: Economic Paradigms, Auctions and Market-Based Systems"
  - "Agent-based and Multi-agent Systems: Computational Social Choice"
  - "Agent-based and Multi-agent Systems: Voting"
---

# Participatory Budgeting with Project Groups

Pallavi Jain, Krzysztof Sornat, Nimrod Talmon, Meirav Zehavi

*Proceedings of the Thirtieth International Joint Conference on Artificial Intelligence*, pages 276-282. DOI: [10.24963/ijcai.2021/39](https://doi.org/10.24963/ijcai.2021/39)

## Abstract

We study a generalization of the standard approval-based model of participatory budgeting (PB), in which voters are providing approval ballots over a set of predefined projects and---in addition to a global budget limit---there are several groupings of the projects, each group with its own budget limit. We study the computational complexity of identifying project bundles that maximize voter satisfaction while respecting all budget limits. We show that the problem is generally intractable and describe efficient exact algorithms for several special cases, including instances with only few groups and instances where the group structure is close to being hierarchical, as well as efficient approximation algorithms. Our results could allow, e.g., municipalities to hold richer PB processes that are thematically and geographically inclusive.