Exploring Welfare Maximization and Fairness in Participatory Budgeting

TL;DR

This dissertation explores new welfare-maximizing and fair PB rules, introduces novel utility and fairness notions, and analyzes their properties across different models with dichotomous and ordinal preferences.

Contribution

It proposes novel PB rules that optimize welfare and fairness, filling gaps in existing literature with new utility and fairness concepts for various PB models.

Findings

New PB rules that maximize welfare and fairness.

Introduction of novel utility and fairness notions.

Comprehensive analysis across different preference and cost models.

Abstract

Participatory budgeting (PB) is a voting paradigm for distributing a divisible resource, usually called a budget, among a set of projects by aggregating the preferences of individuals over these projects. It is implemented quite extensively for purposes such as government allocating funds to public projects and funding agencies selecting research proposals to support. This PhD dissertation studies the welfare-related and fairness-related objectives for different PB models. Our contribution lies in proposing and exploring novel PB rules that maximize welfare and promote fairness, as well as, in introducing and investigating a range of novel utility notions, axiomatic properties, and fairness notions, effectively filling the gaps in the existing literature for each PB model. The thesis is divided into two main parts, the first focusing on dichotomous and the second focusing on ordinal preferences. Each part considers two cases: (i) the cost of each project is restricted to a single value and partial funding is not permitted and (ii) the cost of each project is flexible and may assume multiple values.