New method ensures fair budget choices with additive preferences
Core Up-To-One for Participatory Budgeting with Additive Utilities
Computer Science and Game Theory
Summary
Participatory budgeting lets communities decide how to spend shared funds based on what people value. This paper presents a new way to pick projects that balances everyone's happiness fairly while staying within the budget. The authors show mathematically that their method satisfies a fairness notion called core-up-to-one, meaning no group of people would prefer reallocating the budget by changing just one item. This approach helps guarantee fair outcomes when people express how much they value different options.
What this means in practice
- •For municipal budget planners: Produce budget allocation plans that reflect community preferences fairly and respect spending limits using the new selection rule.
- •For online crowdfunding platforms: Design funding rounds that fairly approximate group satisfaction when participants assign additive values to project options.
A theory result. No direct application yet.
Authors
Piotr Skowron
Abstract
We study participatory budgeting with additive utilities. We introduce a selection rule based on utility-weighted harmonic entropy and a cost penalty, and prove that it returns budget-feasible outcomes satisfying core-up-to-one.