Fair and Inclusive Participatory Budgeting: Voter Experience with Cumulative and Quadratic Voting Interfaces

TL;DR

This paper implements and evaluates cumulative and quadratic voting interfaces in a digital participatory budgeting platform, finding voters prefer more expressive methods despite their complexity, which supports fairness and inclusion.

Contribution

It introduces and assesses the usability of cumulative and quadratic voting interfaces in a real-world digital participatory budgeting platform.

Findings

Voters prefer more expressive voting methods over simpler ones.

Complex voting interfaces are found useful and align with voter preferences.

Expressive voting methods can promote fairness and inclusion in participatory budgeting.

Abstract

Cumulative and quadratic voting are two distributional voting methods that are expressive, promoting fairness and inclusion, particularly in the realm of participatory budgeting. Despite these benefits, graphical voter interfaces for cumulative and quadratic voting are complex to implement and use effectively. As a result, such methods have not seen yet widespread adoption on digital voting platforms. This paper addresses the challenge by introducing an implementation and evaluation of cumulative and quadratic voting within a state-of-the-art voting platform: Stanford Participatory Budgeting. The findings of the study show that while voters prefer simple methods, the more expressive (and complex) cumulative voting becomes the preferred one compared to k-ranking voting that is simpler but less expressive. The implemented voting interface elements are found useful and support the observed voters' preferences for more expressive voting methods. *