AAMAS 2017. Sixteenth International Conference on Antonomous Agents and Multiagent Sytems. Sao Paulo - Brazil. 8th - 12th May, 2017




The goal of multiwinner elections is to select a group of k individuals (the committee) based on the preferences of a number of agents (voters). While the most prominent example of multiwinner elections comes from the world of politics (parliamentary elections held in almost all modern democracies), they are present nearly everywhere and include choosing other representative bodies (e.g., working groups to deal with particular issues), making various business decisions (e.g., choosing products for an Internet store to put on its homepage, choosing movies to put on a transatlantic flight), or shortlisting tasks (e.g., shortlisting applicants for a given academic position).

In this tutorial we will present a number of applications of multiwinner voting (including the ones mentioned above, but also, e.g., their use in genetic algorithms), a number of multiwinner voting rules, and a number of algorithms for computing them (most of the rules are NP-hard to compute). Based on the axiomatic properties of the rules and on simulation results, we will argue which rules are best-suited for particular applications.

No prior knowledge of computational social choice (i.e., COMSOC) is assumed. The attendees interested in COMSOC will learn cutting-edge results and interesting techniques. Multiagent systems designers will learn a new set of tools. Everyone will enjoy a fresh perspective on voting and democracy!


Piotr Faliszewski is an associate professor at the AGH University of Science and Technology in Krakow, Poland. He has obtained his PhD at the University of Rochester, USA, under the supervision of Prof. Lane A. Hemaspaandra. His main interests regard computational social choice, with focus on algorithms for, complexity of, and axiomatic properties of voting mechanisms. So far, he has written over 30 journal papers and 60 conference papers (including a runner-up for AAMAS-2013 best-paper award), several surveys and bookchapters. He was a visiting professor at the University of Auckland (New Zealand) and Universite Paris Dauphine (France). At AGH, he is teaching courses on Algorithms and Data Structures, Computational Complexity Theory, and Algorithmic Game Theory. He has received the 2013 Polityka Research Award (anually granted to five Polish scientists across all areas of science).
  Piotr Faliszewski 
  AGH University of Science and Technology 
  al. Mickiewicza 30 30-059
  Krakow, Poland 

  phone: +48 510-295-166 
Piotr Skowron is currently a postdoctoral fellow at the University of Oxford, from where he will soon move to Technische Universtiät Berlin for a Humboldt fellowship. He obtained his PhD at the University of Warsaw, Poland, under the supervision of Prof. Piotr Faliszewski and Prof. Krzysztof Rzadca. He is interested in algorithmic game theory, multiwinner elections, and scheduling. Piotr was a runner up for the Victor Lesser Distinguished Thesis Award for year 2015. He is an author of five journal papers and over 25 conference papers.
  Piotr Skowron
  University of Oxford
  Wolfson Building, Parks Road, Oxford OX1 3QD
  United Kingdom

Nimrod Talmon is a postdoctoral fellow at the Weizmann Institute of Science. He obtained his PhD at Technische Universität Berlin, Germany, under the supervision of Prof. Rolf Niedermeier. He is interested in algorithmic game theory and computational social choice, with a focus on combinatorial issues in voting (e.g., combinatorial control problems and multiwinner voting). He is an author of 8 journal papers and 20 conference papers. He has received Best PhD Thesis award from the Institute of Software Engineering and Theoretical Computer Science of Technische Universität Berlin. Nimrod is also a professional musician.
  Nimrod Talmon
  Weizmann Instutute of Science
  234 Herzl Street, Rehovot 7610001



Slides: Many of the ideas presented in the tutorial are also covered in the coming-up chaper on multiwinner elections:
  • Multiwinner Voting: A New Challenge for Social Choice Theory, P. Faliszewski, P. Skowron, A. Slinko, N. Talmon, In U. Endriss, editor, Trends in Computational Social Choice, 2017 (to appear)
    Draft of the chapter: ch2_trends_draft.pdf