Program
COMSOC 2025 venue
TUtheSky
at TU Wien, Rooftop lounge
Getreidemarkt 9/BA, 11th floor
1060 Vienna
Public transport to the COMSOC 2025 venue
Subway stop Karlsplatz (U1, U2, U4), walk about 7 minutes
Tram stop Burgring (D), walk about 5 minutes
Registration and information desk
Location: 11th floor of the TU Wien building Getreidemarkt. There will be signs guiding you from the entrance of the building.
Lunch at Mensa TU Wien (Freihaus)
Location: Wiedner Hauptstraße 8, 1040 Vienna
~10 minutes walk from the conference venue, see route here .
Social excursion at the Austrian Parliament
- Important: To enter the Parliament Building, you will need a valid photo ID which will be scanned at the security check (personal and baggage check) in the entrance area and temporarily stored.
Social dinner at Stöckl im Park SALMBRÄU Ges.m.b.H
- Location: Prinz Eugen Straße 2, 1030 Vienna
Program booklet with abstracts
The program including the abstracts for the talks is available as a pdf here
.
Workshop schedule
16.09.2025 Tuesday
For early arrivals: Registration available 17:00-19:00, with an informal reception during the same period.
17.09.2025 Wednesday
| 08:30–09:15 | Registration and opening remarks | |
| 09:15–10:15 | Keynote: Kurt Mehlhorn | Fair Division of Indivisible Goods |
| 10:15–10:45 | Coffee Break | |
| 10:45–11:05 | Akrami, Rathi | Epistemic EFX Allocations Exist for Monotone Valuations |
| 11:05–11:25 | Conati, Niskanen, de Haan, Järvisalo | Computing Efficient and Envy-Free Allocations under Dichotomous Preferences using SAT |
| 11:25–11:45 | Cookson, Ebadian, Shah | Temporal Fair Division |
| 11:45–12:05 | Bouveret, Gilbert, Lang, Méroué | Constrained Serial Dictatorships can be Fair |
| 12:05–14:00 | Lunch Break | |
| 14:00–14:20 | Hornischer, Terzopoulou | Learning How to Vote with Principles: Axiomatic Insights Into the Collective Decisions of Neural Networks |
| 14:20–14:40 | Cailloux, Hervouin, Ozkes, Sanver | Anonymous and neutral classification aggregation |
| 14:40–15:00 | Ravier, Konieczny, Moretti, Viappiani | From order lifting to social ranking: retrieving individual rankings from partial lifted preferences |
| 15:00–18:00 | Excursion to the Austrian Parliament | |
| 18:30–21:00 | Poster Session |
18.09.2025 Thursday
| 08:45–09:45 | Keynote: Axel Ockenfels | Behavioral Market Design |
| 09:45–10:15 | Coffee Break | |
| 10:15–10:35 | Dery | Interactive and Iterative Peer Assessment: A Social Choice Approach to Eliciting and Aggregating Student Evaluations |
| 10:35–10:55 | Horn, Nüsken, Rothe, Seeger | Skating System Unveiled: Exploring Preference Aggregation in Ballroom Tournaments |
| 10:55–11:15 | Ghosh, Neoh, Teh, Tyrovolas | Fraud-Proof Revenue Division on Subscription Platforms |
| 11:15–11:25 | Short Break | |
| 11:25–11:45 | Delemazure, Peters, Freeman, Lang, Laslier | Reallocating Wasted Votes in Proportional Parliamentary Elections with Thresholds |
| 11:45–12:05 | Boehmer, Fish, Procaccia | Generative Social Choice: The Next Generation |
| 12:05–14:00 | Lunch Break | |
| 14:00–14:20 | Prévotat, Terzopoulou, Zylbersztejn | Strategizing under Rule and Vote Uncertainty: An Experiment |
| 14:20–14:40 | Boehmer, Faliszewski, Janeczko, Kaczmarczyk, Lisowski, Pierczyński, Rey, Stolicki, Szufa, Wąs | Guide to Numerical Experiments on Elections in Computational Social Choice |
| 14:40–15:00 | Faliszewski, Janeczko, Kaczmarczyk, Kurdziel, Pierczyński, Szufa | Learning Real-Life Approval Elections |
| 15:00–15:30 | Coffee Break | |
| 15:30–15:50 | Aziz, Lederer, Peters, Peters, Ritossa | Committee Monotonicity and Proportional Representation for Ranked Preferences |
| 15:50–16:10 | Bardal, Brill, McCune, Peters | Proportionality in Practice: Quantifying Proportionality in Ordinal Elections |
| 16:10–16:30 | Short Break | |
| 16:30–16:50 | Bullinger, Romen, Schlenga | The Power of Matching for Online Fractional Hedonic Games |
| 16:50–17:10 | Caragiannis, Roy | Quantile Agent Utility and Implications to Randomized Social Choice |
| 17:10–17:30 | Constantinescu, Wattenhofer | Byzantine Game Theory: Sun Tzu’s Boxes |
| 17:30–17:45 | Group Photo | |
| 18:30–22:00 | Workshop Dinner |
19.09.2025 Friday
| 08:45–09:45 | Keynote: Moon Duchin | Beyond Sushi: Bridging from COMSOC to practical democracy |
| 09:45–10:15 | Coffee Break | |
| 10:15–10:35 | Brandt, Dong, Peters | Condorcet-Consistent Choice Among Three Candidates |
| 10:35–10:55 | Meir, Ghalme | On Condorcet’s Jury Theorem with Abstention |
| 10:55–11:15 | Ding, Yu | An Axiomatic Characterization of the Minimax Voting Method |
| 11:15–11:25 | Short Break | |
| 11:25–11:45 | Berker, Casacuberta, Robinson, Ong, Conitzer, Elkind | From Independence of Clones to Composition Consistency: A Hierarchy of Barriers to Strategic Nomination |
| 11:45–12:05 | Schmidt-Kraepelin, Suksompong, Utke | Discrete Budget Aggregation: Truthfulness and Proportionality |
| 12:05–14:00 | Lunch Break | |
| 14:00–14:20 | Dong, Frank, Peters, Suksompong | Reconfiguring Proportional Committees |
| 14:20–14:40 | Kehne, Schmidt-Kraepelin, Sornat | Robust Committee Voting, or The Other Side of Representation |
| 14:40–15:00 | Masařík, Pierczyński, Skowron | A Generalised Theory of Proportionality in Collective Decision Making |
| 15:00–15:30 | Coffee Break | |
| 15:30–15:50 | Papasotiropoulos, Pishbin, Skibski, Skowron, Wąs | Method of Equal Shares with Bounded Overspending |
| 15:50–16:10 | Kraiczy, Robinson, Elkind | Streamlining Equal Shares |
| 16:10–16:30 | Baychkov, Brill, Utke | Mixed Voting Rules for Participatory Budgeting |
| 16:30–16:50 | Short Break | |
| 16:50–17:10 | Nguyen, Song | Approximate Core of Participatory Budgeting via Lindahl Equilibrium |
| 17:10–17:30 | Faliszewski, Janeczko, Knop, Pokorný, Schierreich, Słuszniak, Sornat | Participatory Budgeting Project Strength via Candidate Control |
| 17:30–19:00 | Business Meeting |
Keynotes Abstracts
Keynote Kurt Mehlhorn: Who Gets What? Fair Division of Indivisible Goods
A set of indivisible goods, e.g., a car, a house, a toothbrush, …, has to be split among a set of agents in a fair manner. Each agent has its own valuation function for sets of goods. What constitutes a fair allocation? When does a fair allocation exist? If it exists, can we compute it efficiently? Can we approximate fair allocations? There are three main notions of fairness in the literature: Envy-based, Share-based, and maximum Nash Social Welfare. I will discuss all three notions and survey what is known.
Keynote Axel Ockenfels: Behavioral Market Design
Addressing pressing economic and social challenges – such as pandemics, climate change, and energy scarcity – requires changes in behavior. In this talk, I will use case studies, primarily from my own research, to illustrate how human behavior and bounded rationality influences the design of institutions aimed at aligning incentives and actions with overarching goals. Economic design research and behavioral science are often complementary, rather than substitutes, in promoting effective behavioral change.
Keynote Moon Duchin: Beyond Sushi: Bridging from COMSOC to practical democracy
In this talk, I’ll start with a (qualified) success story for computational tools in democracy reform: a case study of U.S. redistricting, where graph algorithms have made surprising impacts on legal work around voting rights. Then I’ll explain how perspectives from law and policy can help guide approaches to core questions in other areas of computational social choice, including definitions of key concepts like cohesion and proportionality. As one theme, I’ll develop some descriptive statistics for preference profiles from political elections, which helps frame the challenges of building generative models of preference that better align with messy real-world behavior.
Short Talks Abstracts
See accepted papers