Participatory Budgeting: Data, Tools, and Analysis

TL;DR

This paper introduces a comprehensive library and tools for participatory budgeting data analysis, demonstrating that alternative rules can improve fairness and utility in project selection.

Contribution

It provides open source data and tools, and compares different selection rules, highlighting the fairness and utility benefits of the Method of Equal Shares.

Findings

Method of Equal Shares yields fairer outcomes than Utilitarian Greedy.

Proportional rules can often replace district/category divisions, increasing voter utility.

Using alternative rules improves overall fairness and utility in participatory budgeting.

Abstract

We provide a library of participatory budgeting data (Pabulib) and open source tools (Pabutools and Pabustats) for analysing this data. We analyse how the results of participatory budgeting elections would change if a different selection rule was applied. We provide evidence that the outcomes of the Method of Equal Shares would be considerably fairer than those of the Utilitarian Greedy rule that is currently in use. We also show that the division of the projects into districts and/or categories can in many cases be avoided when using proportional rules. We find that this would increase the overall utility of the voters.