Professional Activities

For current events and activities, please also see the main page. There is a separate page listing seminar talks.

Multi-year Roles

Head of the Theoretical Computer Science Unit of the ILLC (since 2021)
Head of the (former) Logic and Computation Unit of the ILLC (2011-2016; deputy head, 2010-2011)
Director of the Master of Logic Programme of the ILLC (2010-2015)
SCW: Social Choice and Welfare (associate editor, since 2024)
JAIR: Journal of Artificial Intelligence Research (associate editor, 2015-2024; editorial board member, 2010-2015)
AIJ: Artificial Intelligence Journal (associate editor, 2013-2020)
JAAMAS: Journal of Autonomous Agents and Multiagent Systems (associate editor, 2007-2019)
SSCW: Society for Social Choice and Welfare (elected member of the council, 2016-2022)
IFAAMAS: International Foundation for Autonomous Agents and Multiagent Systems (elected member of the board of directors, 2012-2018)
COST Action IC1205 on Computational Social Choice (chair, 2012-2016)
COST Action IC0602 on Algorithmic Decision Theory (vice chair, 2007-2011)
COMSOC: International Workshop on Computational Social Choice (founder and steering committee member, 2006-2012)
DSCC: Dutch Social Choice Colloquium (co-organiser, since 2016)
COMSOC Video Seminar (chair of the steering committee, 2020-2023)
EurAI: Fellow of the European Association for Artificial Intelligence (since 2023)

2025

3rd Amsterdam/Saint-Etienne Workshop on Social Choice, Amsterdam, April 2025 (co-organiser)
AAMAS-2025: 24th International Conference on Autonomous Agents and Multiagent Systems, Detroit, May 2025 (PC member, doctoral consortium reviewer)
SING20: 20th European Meeting on Game Theory, Maastricht, June 2025 (invited speaker)
Dagstuhl Seminar on Societal Impact of Computational Social Choice, September/October 2025 (invited participant)

2024

2nd Amsterdam/Saint-Etienne Workshop on Social Choice, Saint-Etienne, March 2024 (co-organiser)
AAMAS-2024: 23rd International Conference on Autonomous Agents and Multiagent Systems, Auckland, May 2024 (area chair)
SCaLA-2024, Workshop on Social Choice and Learning Algorithms, Auckland, May 2024 (PC member)
ICMS Workshop on Mathematics of Voting and Representation, Edinburgh, June 2024 (invited speaker)
SCW-2024: 17th Meeting of the Society for Social Choice and Welfare, Paris, July 2024 (PC member)
SAGT-2024: 17th International Symposium on Algorithmic Game Theory, Amsterdam, September 2024 (member of the organising committee)
ECAI-2024 (proceedings, faq): 27th European Conference on Artificial Intelligence, Santiago de Compostela, October 2024 (PC co-chair)
Member of PhD Committee for Dr. Guillermo Menéndez Turata, University of Amsterdam (ILLC), January 2024
Member of PhD Committee for Dr. Patrick Lederer, TU München, March 2024
Member of PhD Committee for Dr. Grzegorz Pierczyński, University of Warsaw, June 2024
Member of PhD Committee for Dr. Willem Feijen, University of Amsterdam (CWI), December 2024

2023

1st Amsterdam/Saint-Etienne Workshop on Social Choice, Amsterdam, March 2023 (co-organiser)
Awesome IT 2023, Amsterdam, May 2023 (invited speaker)
AAMAS-2023: 22nd International Conference on Autonomous Agents and Multiagent Systems, London, May/June 2023 (doctoral consortium co-chair, SPC member, Outstanding SPC Member Award)
AAMAS-2023 Tutorial on Automated Reasoning for Social Choice Theory, London, May 2023 (lecturer)
COMSOC-2023: 9th International Workshop on Computational Social Choice, Beersheba, July 2023 (PC member)
PFIA-2023: Plate-Forme Intelligence Artificielle, Strasbourg, July 2023 (invited speaker)
Summer School on Computational Social Choice, Amsterdam, July 2023 (organiser)
IJCAI-2023: 32nd International Joint Conference on Artificial Intelligence, Cape Town, August 2023 (journal track chair, SPC member, doctoral consortium reviewer)
ECAI-2023: 26th European Conference on Artificial Intelligence, Kraków, September/October 2023 (SPC member)
Talk on "How to write a review" at ECAI-2023 Doctoral Consortium, Kraków, September 2023 (invited speaker)
ECAI-2023 Tutorial on Automated Reasoning for Social Choice Theory, Kraków, September 2023 (lecturer)
Workshop on Participatory Budgeting, Amsterdam, October 2023 (co-organiser)
Mini Workshop on Social Choice Theory, Groningen, November 2023 (invited speaker)
Member of PhD Committee for Dr. Yuliya Veselova, Maastricht University, September 2023
Member of PhD Committee for Dr. Yuzhe Zhang, University of Groningen, November 2023
Member of PhD Committee for Dr. Gogulapati Sreedurga, Indian Institute of Science, Bangalore, December 2023
Graduated Dr. Simon Rey, University of Amsterdam (ILLC), October 2023 (thesis)

2022

Workshop on Formal Models of Democracy, Rotterdam, April 2022 (invited speaker)
GAIW-2022: 4th Games, Agents and Incentives Workshop, Online, May 2020 (PC member)
AAMAS-2022: 21st International Conference on Autonomous Agents and Multiagent Systems, Online, May 2022 (PC member for main and Blue Sky Ideas track)
Workshop on Computational and Topological Social Choice, Mexico City, June 2022 (invited speaker)
MPREF-2022: 13th Multidisciplinary Workshop on Advances in Preference Handling, July 2022 (PC member)
IJCAI-ECAI-2022: 31st International Joint Conference on Artificial Intelligence and 25th European Conference on Artificial Intelligence, Vienna, July 2022 (area chair)
Lorentz Center Workshop on Algorithmic Technology for Democracy, October 2022 (invited participant)
IA2 Autumn School on AI and Preferences, Porquerolles, October 2022 (invited lecturer)
OSGAD-2022: Seminar on Ordered Structures in Games and Decision, Paris, November 2022 (invited speaker)

2021

AAMAS-2021 (proceedings, faq): 20th International Conference on Autonomous Agents and Multiagent Systems, Online, May 2021 (PC co-chair)
COMSOC-2021: 8th International Workshop on Computational Social Choice, Haifa/Online, June 2021 (PC member)
ADT-2021: 7th International Conference on Algorithmic Decision Theory, Toulouse, October 2021 (PC member)
Workshop on Social Choice Theory, Amsterdam, November 2021 (co-organiser)
Graduated Dr. Zoi Terzopoulou, University of Amsterdam (ILLC), June 2021 (thesis)
Graduated Dr. Sirin Botan, University of Amsterdam (ILLC), November 2021 (thesis)

2020

Conference in Honour of Hans Peters on Social Choice, Game Theory, and Applications, Maastricht, January 2020 (invited speaker)
AAAI-2020: 34th AAAI Conference on Artificial Intelligence, New York, February 2020 (area chair)
GAIW-2020: 2nd Games, Agents and Incentives Workshop, Online, May 2020 (PC member)
AAMAS-2020: 19th International Conference on Autonomous Agents and Multiagent Systems, Online, May 2020 (SPC member, Best SPC Member Award, doctoral consortium mentor)
ECAI-2020: 24th European Conference on Artificial Intelligence, Online, August/September 2020 (SPC member)
Workshop on Social Choice Theory: "Beyond Strategyproofness", Online, November 2020 (invited speaker)
NeurIPS-2020: 34th Conference on Neural Information Processing Systems, Online, December 2020 (auxiliary reviewer, recognised as top-10% reviewer)
IJCAI-PRICAI-2020: 29th International Joint Conference on Artificial Intelligence and 17th Pacific Rim International Conference on Artificial Intelligence, Online, January 2021 (area chair)
Member of PhD Committee for Dr. Jan Maly, TU Wien, September 2020
Member of PhD Committee for Dr. Hossein Khani, Université Paris-Dauphine, October 2020

2019

AAAI-2019: 33rd AAAI Conference on Artificial Intelligence, Honolulu, Hawaii, January/February 2019 (SPC member)
Workshop on Individual Preferences and Social Choice, Graz, April 2019 (invited speaker)
JELIA-2019: 16th European Conference on Logics in Artificial Intelligence, Rende, May 2019 (PC member)
GAIW-2019: 1st Games, Agents and Incentives Workshop, Montréal, May 2019 (PC member)
AAMAS-2019: 18th International Conference on Autonomous Agents and Multiagent Systems, Montréal, May 2019 (area chair)
CoCoRICo Workshop on Collective Decision Making, Paris, May 2019 (invited panelist)
3rd ILLC Workshop on Collective Decision Making, Amsterdam, June 2019 (organiser)
IJCAI-2019: 28th International Joint Conference on Artificial Intelligence, Macao, August 2019 (area chair)
Dagstuhl Seminar on Application-Oriented Computational Social Choice, September 2019 (invited participant)
E-Vote-ID 2019: 4th International Joint Conference on Electronic Voting, Bregenz, October 2019 (PC member)
SRA-2019: 2nd Interdisciplinary Workshop on Social Responsibility of Algorithms, Paris, December 2019 (invited speaker)
Visiting Professor (professeur invité), LAMSADE, Université Paris-Dauphine, October 2019

2018

SCW-2018: 14th Meeting of the Society for Social Choice and Welfare, Seoul, June 2018 (PC member)
OE-2018: 1st International Workshop on Ontology of Economics, Cape Town, September 2018 (PC member)
Member of PhD Committee for Dr. Anaëlle Wilczynski, Université Paris-Dauphine, December 2018

2017

AAAI-2017: 31st AAAI Conference on Artificial Intelligence, San Francisco, California, February 2017 (SPC member)
Workshop on Formal Argumentation in Online Discussions, Düsseldorf, April 2017 (invited speaker)
AAMAS-2017: 16th International Conference on Autonomous Agents and Multiagent Systems, São Paulo, May 2017 (SPC member, finalist for the Best SPC Member Award)
Dagstuhl Seminar on Voting: Beyond Simple Majorities and Single-Winner Elections, June 2017 (invited participant)
IJCAI-2017: 26th International Joint Conference on Artificial Intelligence, Melbourne, August 2017 (area chair)
Member of PhD Committee for Dr. Swarnendu Chatterjee, Maastricht University, September 2017
NWO Vici Award 2017 for a project on Collective Information [awarded February 2018]

2016

AAAI-2016: 30th AAAI Conference on Artificial Intelligence, Phoenix, Arizona, February 2016 (SPC member)
NIAS Workshop on Voting, Power and Decision-Making, Netherlands Institute for Advanced Study in the Humanities and Social Sciences, Wassenaar, March 2016 (invited participant)
KR-2016: 15th International Conference on Principles of Knowledge Representation and Reasoning, Capetown, April 2016 (PC member)
AAMAS-2016: 15th International Conference on Autonomous Agents and Multiagent Systems, Singapore, May 2016 (SPC member)
Dagstuhl Seminar on Fair Division, June 2016 (invited participant)
COST Action IC1205 Industry Day, Toulouse, June 2016 (co-organiser)
COMSOC-2016: 6th International Workshop on Computational Social Choice, Toulouse, June 2016 (PC member)
IJCAI-2016: 25th International Joint Conference on Artificial Intelligence, New York City, July 2016 (SPC member)
COST Action IC1205 Summer School on Computational Social Choice, Miramar Palace, San Sebastián, July 2016 (co-organiser)
STAIRS-2016: 8th European Starting Artificial Intelligence Researcher Symposium, The Hague, August 2016 (PC member)
ECAI-2016: 22nd European Conference on Artificial Intelligence, The Hague, August/September 2016 (SPC member)
COST Action IC1205 Workshop on Future Directions in Computational Social Choice, Budapest, November 2016 (co-organiser)
Member of PhD Committee for Dr. Andrea Loreggia, University of Padova, March 2016
Member of PhD Committee for Dr. Shaun White, University of Auckland, September 2016
Visiting Professor (professeur invité), LAMSADE, Université Paris-Dauphine, January/February 2016
Visiting Professor (professeur invité), LIP6, Université Pierre et Marie Curie, Paris, February/March 2016
Visiting Academic, Centre for Philosophy of Natural and Social Science, London School of Economics, April/May 2016

2015

Public Lecture on Collective Annotation at the FNWI Student Colloquium, University of Amsterdam, January 2015 (outreach)
AAAI-2015: 29th AAAI Conference on Artificial Intelligence, Austin, Texas, January 2015 (SPC member)
2nd ILLC Workshop on Collective Decision Making, Amsterdam, March 2015 (organiser)
SMART Cognitive Science: Workshop on Communication and Agency, Amsterdam, March 2015 (invited speaker)
Public Lecture on Cake Cutting at Leve de Wiskunde!, University of Amsterdam, April 2015 (outreach)
ACAN-2015: 8th International Workshop on Agent-based Complex Automated Negotiations, Istanbul, May 2015 (invited speaker)
AAMAS-2015: 14th International Conference on Autonomous Agents and Multiagent Systems, Istanbul, May 2015 (PC member, exhibition chair, doctoral consortium mentor)
Dagstuhl Seminar on Computational Social Choice: Theory and Applications, June 2015 (invited participant)
TTL-2015: 4th International Conference on Tools for Teaching Logic, Rennes, June 2015 (PC member)
Lorentz Center Workshop on Clusters, Games and Axioms, June 2015 (invited participant)
FairDiv-2015: COST Summer School on Fair Division, Grenoble, July 2015 (lecturer)
IJCAI-2015: 24th International Joint Conference on Artificial Intelligence, Buenos Aires, July/August 2015 (area chair for KR and sponsorship co-chair)
ADT-2015: 4th International Conference on Algorithmic Decision Theory, Lexington, Kentucky, September 2015 (PC member)
MATES-2015: 13th German Conference on Multiagent System Technologies, Cottbus, September/October 2015 (PC member)
Public Lecture on Social Choice and Democracy for the Société Européenne de Culture (Nederland), Amsterdam, November 2015 (outreach)
LABEX CIMI Pluridisciplinary Workshop on Game Theory, Toulouse, November 2015 (invited speaker)
WINE-2015: 11th Conference on Web and Internet Economics, Amsterdam, December 2015 (PC member)
Member of PhD Committee for Dr. Piotr Skowron, University of Warsaw, April 2015
Visiting Professor (professeur invité), University of Toulouse 1, November/December 2015

2014

Workshop on Iterative Voting and Voting Games, Padova, January 2014 (invited speaker)
KNAW Academy Colloquium on Dependence Logic: Amsterdam, March 2014 (invited speaker)
Lectures on the Theory of Aggregation, Sun Yat-Sen University, Guangzhou, April 2014 (invited lecturer)
Workshop on Fair Division, Voting and Computational Complexity, Graz, April 2014 (invited speaker)
AAMAS-2014: 13th International Conference on Autonomous Agents and Multiagent Systems, Paris, May 2014 (SPC member and doctoral consortium mentor)
Dagstuhl Seminar on Judgment Aggregation for Artificial intelligence, May 2014 (co-chair)
Lectures on Computational Social Choice, Higher School of Economics, Moscow, May 2014 (invited lecturer)
COMSOC-2014: 5th International Workshop on Computational Social Choice, Pittsburgh, Pennsylvania, June 2014 (PC member and panelist)
SINTELNET Workshop Arguing on the Web 2.0, Amsterdam, June/July 2014 (local organiser)
NMR-2014: 15th International Workshop on Non-Monotonic Reasoning, Vienna, July 2014 (PC member)
KR-2014: 14th International Conference on Principles of Knowledge Representation and Reasoning, Vienna, July 2014 (PC member)
AAAI-2014: 28th AAAI Conference on Artificial Intelligence, Québec City, July 2014 (PC member, Outstanding PC Member Award)
ECAI-2014: 21st European Conference on Artificial Intelligence, Prague, August 2014 (PC member)
STAIRS-2014: 7th European Starting Artificial Intelligence Researcher Symposium, Prague, August 2014 (co-chair)
KES-2014: 18th International Conference on Knowledge-Based and Intelligent Information and Engineering Systems, Gdynia, September 2014 (invited speaker)
MATES-2014: 12th German Conference on Multiagent System Technologies, Stuttgart, September 2014 (invited speaker)
JELIA-2014: 14th European Conference on Logics in Artificial Intelligence, Madeira, September 2014 (PC member)
Public Lecture on Moeilijke Beslissingen, SPUI25 Academic-Cultural Centre, Amsterdam, October 2014 (outreach)
Evening Lecture on Tough Choices for the Interdisciplinair Alumni Netwerk Amsterdam (IANA), De Badcuyp, Amsterdam, November 2014 (outreach)
FAIR-2014: Forum for Artificial Intelligence Research Summer School, Stellenbosch, December 2014 (invited lecturer)
Member of PhD Committee for Dr. Albert Pla, University of Girona, April 2014
Member of PhD Committee for Dr. Eva Hendriks, University of Amsterdam (Economics), June 2014
Voted "Lecturer of the Year" at the Faculty of Science, University of Amsterdam

2013

Tutorial on Judgment Aggregation at the IMS Programme on Algorithmic Game Theory and Computational Social Choice, Singapore, January 2013 (invited lecturer)
1st ILLC Workshop on Collective Decision Making, Amsterdam, April 2013 (organiser)
6th Munich-Sydney-Tilburg Conference on "Models and Decisions", Munich, April 2013 (PC member)
AAMAS-2013: 12th International Conference on Autonomous Agents and Multiagent Systems, Saint Paul, Minnesota, May 2013 (PC member, Best PC Member Award)
AAMAS-2013 Tutorial on Judgment Aggregation, Saint Paul, Minnesota, May 2013 (lecturer)
CiE-2013: Computability in Europe, Milan, July 2013 (invited speaker)
EASSS-2013 Tutorial on Voting Theory, London, July 2013 (lecturer)
AAAI-2013: 27th AAAI Conference on Artificial Intelligence, Bellevue, Washington, July 2013 (PC member)
IJCAI-2013: 23rd International Joint Conference on Artificial Intelligence, Beijing, August 2013 (area chair for MAS and doctoral consortium mentor)
ESSLLI Workshop on Logical Models of Group Decision Making, Düsseldorf, August 2013 (co-chair)
ESSLLI-2013 Course on Logic and Social Choice Theory, Düsseldorf, August 2013 (lecturer)
ICCCI-2013: 5th International Conference on Computational Collective Intelligence Technologies and Applications, Craiova, September 2013 (invited speaker)
LORI-2013: 4th International Workshop on Logic, Rationality and Interaction, Hangzhou, October 2013 (PC member)
Member of PhD Committee for Dr. Lachlan Dufton, University of Waterloo, January 2013
Organised reaccreditation effort for the MSc Logic (report)

2012

Lorentz Center Workshop on Modeling Strategic Reasoning, February 2012 (invited participant)
Dagstuhl Seminar on Computation and Incentives in Social Choice, March 2012 (invited participant)
AAMAS-2012: 11th International Conference on Autonomous Agents and Multiagent Systems, Valencia, June 2012 (PC member)
NMR-2012: 14th International Workshop on Non-Monotonic Reasoning, Rome, June 2012 (PC member)
KR-2012: 13th International Conference on Principles of Knowledge Representation and Reasoning, Rome, June 2012 (PC member)
LOFT-2012: 10th Conference on Logic and the Foundations of Game and Decision Theory, Sevilla, June 2012 (PC member)
Tutorial on Voting Theory at the 2nd International Summer School on Secure Voting, Schloss Dagstuhl, July 2012 (invited lecturer)
AAAI-2012: 26th AAAI Conference on Artificial Intelligence, Toronto, July 2012 (SPC member)
ECAI-2012: 20th European Conference on Artificial Intelligence, Montpellier, August 2012 (PC member)
MPREF-2012: 6th Multidisciplinary Workshop on Advances in Preference Handling, Montpellier, August 2012 (PC member)
BNC-2012: ECAI Workshop on Belief Change, Nonmonotonic Reasoning and Conflict Resolution, Montpellier, August 2012 (PC member)
COMSOC-2012: 4th International Workshop on Computational Social Choice, Kraków, September 2012 (PC member)
JELIA-2012: 13th European Conference on Logics in Artificial Intelligence, Toulouse, September 2012 (PC member)
Workshop on Frameworks for Multiagent Aggregation, Amsterdam, September 2012 (co-organiser)
Tutorial on Judgment Aggregation at the 8th Workshop on Internet and Network Economics (WINE-2012), Liverpool, December 2012 (invited lecturer)
Member of PhD Committee for Dr. Marija Slavkovik, University of Luxembourg, January 2012
Member of PhD Committee for Dr. Dorothea Baumeister, University of Düsseldorf, September 2012
Member of PhD Committee for Dr. Pietro Galliani, University of Amsterdam (ILLC), September 2012
Member of PhD Committee for Dr. Wietske Visser, TU Delft, December 2012
Graduated Dr. Umberto Grandi, University of Amsterdam (ILLC), September 2012 (thesis)

2011

Dagstuhl Seminar on Reasoning about Interaction: From Game Theory to Logic and Back, March 2011 (invited participant)
Session on Computational Social Choice at the European Future Technologies Conference and Exhibition (FET'11), Budapest, May 2011 (organiser)
AAMAS-2011: 10th International Joint Conference on Autonomous Agents and Multiagent Systems, Taipei, May 2011 (SPC member)
RAMiCS-2011: 12th International Conference on Relational and Algebraic Methods in Computer Science, Rotterdam, May/June 2011 (PC member)
EASSS-2011 (call for tutorials): 13th European Agent Systems Summer School, Girona, July 2011 (programme co-chair)
IJCAI-2011: 22nd International Joint Conference on Artificial Intelligence, Barcelona, July 2011 (SPC member)
IJCAI Workshop on Soical Choice and Artificial Intelligence (proceedings), Barcelona, July 2011 (co-chair)
CLIMA-2011: 12th International Workshop on Computational Logic in Multiagent Systems, Barcelona, July 2011 (invited speaker)
AAAI-2011: 25th AAAI Conference on Artificial Intelligence, San Francisco, August 2011 (PC member)
Tutorial on Computational Social Choice at the 9th Tbilisi Symposium on Language, Logic and Computation, Kutaisi, September 2011 (invited lecturer)
LORI-2011: 3rd International Workshop on Logic, Rationality and Interaction, Guangzhou, October 2011 (PC member)
ADT-2011: 2nd International Conference on Algorithmic Decision Theory, DIMACS/Piscataway, NJ, October 2011 (PC member)
Member of PhD Committee for Dr. Fernando Velázquez-Quesada, University of Amsterdam (ILLC), February 2011
Member of PhD Committee for Dr. Helena Keinänen, Turku School of Economics, June 2011
Member of PhD Committee for Dr. Stefan Minica, University of Amsterdam (ILLC), December 2011

2010

Dagstuhl Seminar on Computational Foundations of Social Choice, March 2010 (invited participant)
Course on Fair Division at the COST-ADT Doctoral School on Computational Social Choice, Estoril, Portugal, April 2010 (lecturer)
KR-2010: 12th International Conference on Principles of Knowledge Representation and Reasoning, Toronto, May 2010 (PC member)
AAMAS-2010: 9th International Conference on Autonomous Agents and Multiagent Systems, Toronto, May 2010 (SPC member)
EC-2010: 11th ACM Conference on Electronic Commerce, Harvard, June 2010 (PC member)
LOFT-2010: 9th Conference on Logic and the Foundations of Game and Decision Theory, Toulouse, July 2010 (PC member)
AAAI-2010: 24th AAAI Conference on Artificial Intelligence, Atlanta, July 2010 (PC member)
AAAI-2010 Tutorial on Voting Theory, Atlanta, July 2010 (lecturer)
SCW-2010: 10th Meeting of the Society for Social Choice and Welfare, Moscow, July 2010 (PC member)
ECAI-2010 (workshop call): 19th European Conference on Artificial Intelligence, Lisbon, August 2010 (workshop chair and PC member)
ECAI-2010 Tutorial on Computational Social Choice, Lisbon, August 2010 (invited lecturer)
JELIA-2010: 12th European Conference on Logics in Artificial Intelligence, Helsinki, September 2010 (PC member)
COMSOC-2010: 3rd International Workshop on Computational Social Choice, Düsseldorf, September 2010 (PC member)

2009

SAC-AT-2009: 24th ACM Symposium on Applied Computing, Track on Agreement Technologies, Honolulu, March 2009 (PC member)
AAMAS-2009: 8th International Conference on Autonomous Agents and Multiagent Systems, Budapest, May 2009 (PC member)
AMEC-2009: 11th Workshop on Agent-mediated Electronic Commerce, Budapest, May 2009 (PC member)
OPTMAS-2009: 2nd International Workshop on Optimisation in Multiagent Systems, Budapest, May 2009 (PC member)
SocInfo-2009: International Conference on Social Informatics, Warsaw, June 2009 (PC member and invited speaker)
EC-2009: 10th ACM Conference on Electronic Commerce, Stanford, California, July 2009 (PC member)
SS@EASSS-2009: Student Session of the 11th European Agent Systems Summer School, Torino, August/September 2009 (PC member)
EASSS-2009 Course: Fair Division, Torino, August/September 2009 (lecturer)
ADT-2009: 1st International Conference on Algorithmic Decision Theory, Venice, October 2009 (PC member)
Member of PhD Committee for Dr. Andreas Witzel, University of Amsterdam (ILLC), September 2009
Graduated Dr. Joel Uckelman, University of Amsterdam (ILLC), December 2009 (thesis)

2008

AAMAS-2008: 7th International Conference on Autonomous Agents and Multiagent Systems, Estoril, Portugal, May 2008 (SPC member, finalist for the Best SPC Member Award)
AAMAS-2008 Tutorial: Fair Division, Estoril, Portugal, May 2008 (lecturer)
AMEC-2008: 10th Workshop on Agent-mediated Electronic Commerce, Estoril, Portugal, May 2008 (PC member)
3rd MARA Get-Together: Workshop on Multiagent Resource Allocation, Amsterdam, June 2008 (chair)
LOFT-2008: 8th Conference on Logic and the Foundations of Game and Decision Theory, Amsterdam, July 2008 (PC member)
EC-2008: 9th ACM Conference on Electronic Commerce, Chicago, July 2008 (PC member)
AAAI-2008: 23rd AAAI Conference on Artificial Intelligence, Chicago, July 2008 (PC member)
ECAI-2008: 18th European Conference on Artificial Intelligence, Patras, July 2008 (PC member)
ESSLLI-2008 Course: Introduction to Computational Social Choice, Hamburg, August 2008 (lecturer)
COMSOC-2008 (proceedings): 2nd International Workshop on Computational Social Choice, Liverpool, September 2008 (co-chair)
KR-2008: 11th International Conference on Principles of Knowledge Representation and Reasoning, Sydney, September 2008 (PC member)
SBIA-2008: 19th Brazilian Symposium on Artificial Intelligence, Salvador, Bahia, October 2008 (PC member)
EUMAS-2008: 6th European Workshop on Multiagent Systems, Bath, December 2008 (PC member)
Guest Researcher, CSLI, Stanford University, January 2008
Visiting Professor (professeur invité), LAMSADE, Université Paris-Dauphine, July 2008

2007

LCD-2007: Workshop on Logics and Collective Decision Making, Lille, March 2007 (PC member)
ARW-2007: 14th Workshop on Automated Reasoning, London, April 2007 (PC member)
AAMAS-2007: 6th International Conference on Autonomous Agents and Multiagent Systems, Honolulu, May 2007 (PC member)
AMEC-2007: 9th Workshop on Agent-mediated Electronic Commerce, Honolulu, May 2007 (PC member)
DALT-2007: 5th International Workshop on Declarative Agent Languages and Technologies, Honolulu, May 2007 (PC member)
EC-2007: 8th ACM Conference on Electronic Commerce, San Diego, June 2007 (PC member)
EASSS-2007 Course: Multiagent Resource Allocation, Durham, August 2007 (co-lecturer)
LADS-2007: Workshop on Languages, Methodologies and Development Tools for Multiagent Systems, Durham, September 2007 (PC member)
Tbilisi-2007: 7th International Tbilisi Symposium on Language, Logic and Computation, October 2007 (PC member)
Dagstuhl Seminar on Computational Issues in Social Choice, October 2007 (co-chair)
BNAIC-2007: 19th Belgian-Dutch Conference on Artificial Intelligence, Utrecht, November 2007 (PC member)
EUMAS-2007: 5th European Workshop on Multiagent Systems, Hammamet, Tunisia, December 2007 (PC member)
Member of PhD Committee for Dr. Sylvain Bouveret, University of Toulouse and Supaéro, November 2007
NWO Vidi Award 2007 for a project on Collective Decision Making in Combinatorial Domains

2006

ARW-2006: 13th Workshop on Automated Reasoning, Bristol, April 2006 (PC member)
DALT-2006 (proceedings): 4th International Workshop on Declarative Agent Languages and Technologies, Hakodate, May 2006 (co-chair)
AAMAS-2006: 5th International Joint Conference on Autonomous Agents and Multiagent Systems, Hakodate, May 2006 (PC member)
AAMAS-2006 Tutorial: Multiagent Resource Allocation, Hakodate, May 2006 (lecturer)
EASSS-2006 Course: Multiagent Resource Allocation, Annecy, July 2006 (co-lecturer)
ECAI-2006: 17th European Conference on Artificial Intelligence, Lake Garda, August 2006 (PC member)
COMSOC-2006 (proceedings): 1st International Workshop on Computational Social Choice, Amsterdam, December 2006 (co-chair)
Member of PhD Committee for Dr. Sylvia Estivie, Université Paris-Dauphine, December 2006

2005

ARW-2005: 12th Workshop on Automated Reasoning, Edinburgh, July 2005 (PC member and secretary/treasurer)
DALT-2005 (proceedings): 3rd International Workshop on Declarative Agent Languages and Technologies, Utrecht, July 2005 (co-chair)
MARA I: 1st Meeting of the AgentLink Technical Forum Group on Multiagent Resource Allocation (TFG-MARA), Ljubljana, February/March 2005 (chair)
MARA II: 2nd Meeting of the AgentLink Technical Forum Group on Multiagent Resource Allocation (TFG-MARA), Budapest, September 2005 (chair)

2004 and before

ARW-2004: 11th Workshop on Automated Reasoning, Leeds, March/April 2004 (PC member and secretary/treasurer)
ARW-2003: 10th Workshop on Automated Reasoning, Liverpool, April 2003 (PC member and secretary/treasurer)
ARW-2002: 9th Workshop on Automated Reasoning, London, April 2002 (PC member and secretary/treasurer)
ARW-2001: 8th Workshop on Automated Reasoning, York, March 2001 (PC member and secretary/treasurer)
ARW-2000 (proceedings): 7th Workshop on Automated Reasoning, London, July 2000 (local co-organiser)
1st International Congress on Tools for Teaching Logic, Salamanca, June 2000 (invited speaker)
Guest Researcher, Department of Informatics, University of Pisa, May/June 2004
Guest Researcher, LIIA, ENSAIS Strasbourg, May/June 2000
Guest Researcher, Department of Philosophy, University of Ferrara, several short stays during 1997 and 1998