12 papers
A Polynomial-Time Rule Satisfying Full Justified Representation
Fabian Frank, Jannik Peters
In approval-based multiwinner voting, voters submit an approval ballot on which basis a committee of fixed size has to be selected. Compared to single-winner voting this makes…
Beyond Lower Quota: Avoiding Overrepresentation in Multi-Winner Voting
Anton Baychkov, Martin Lackner, Jan Maly +2
Recently, in the social choice literature, much attention has been given to the question of avoiding underrepresentation in approval-based multi-winner voting. In this paper, we ex…
Two Observations on Metric Distortion and Condorcet Winning Sets
Jannik Peters
In this research note we briefly connect two well-studied topics in computational social choice: metric distortion and the selection of undominated committees. In particular, we sh…
An Axiomatic Analysis of Proportionality Notions in Approval-Based Multiwinner Voting
Chris Dong, Jannik Peters
Even though proportional representation is a fundamental goal in multiwinner voting and a plethora of proportionality notions has been introduced, the normative justifications for…
Explanation Systems for Approval-Based Multiwinner Voting
Niclas Boehmer, Luca Kreisel, Jannik Peters
In approval-based multiwinner voting, voters express approval preferences over a set of candidates, and the goal is to return a winning committee. This model captures a broad range…
Candidate Monotonicity and Proportionality for Lotteries and Non-Resolute Rules
Jannik Peters
We study the problem of designing multiwinner voting rules that are candidate monotone and proportional. We show that the set of committees satisfying the proportionality axiom of…