Conference announcement: 30 Years of Game Theory at Institut Henri Poincaré, October 06-10, 2025, Paris.

Welcome

The Séminaire parisien de Théorie des Jeux is an open, inter-institutional, multi-disciplined seminar which covers all fields of game theory. It takes place on Monday from 11:00 to 12:00 am at Institut Henri Poincaré, 11 rue Pierre et Marie Curie, Paris 5ème. MAP

You will find the program for the current academic year on the page 2025/2026 and the program for past years on the page Archives.

The junior seminar welcomes PhD students in game theory to present their work.  You will find the program for the current academic year on the page Junior Seminar 2025/2026.

Next seminar:  

November 24, 2025 (room Pierre Grisvard): 

Paul-Henry MOISSON (PSE) 

will present ; Political Cycles over Worldviews: Increments and Backlashes in Complexity (joint with Philippe Jehiel)

Abstract : "We develop a dynamic model of political competition in which politicians propose worldviews to explain observed outcomes, and policies adapted to these worldviews. Voters differ in their ability to understand worldviews, which we parameterize by how many categories of scenarios they can encompass. In a given period, voters choose between the incumbent and a challenger politician, and vote for the one who proposes the most plausible worldview among those they understand. This in turn determines the current-period policy, which is added to the set of observations to be explained in the next period. We consider the ergodic distributions over worldviews and corresponding policies that can arise from such dynamics. We show that there may be multiple ergodic distributions, but in all of them the complexity of the winning worldview follows a deterministic cycle, composed of steady increments towards higher complexity, interrupted by a backlash towards the simplest worldview which consistently picks the short-termist policy no matter how inefficient that policy may be. We consider the implications of our model in terms of voting turnout, support for the winning politician and efficiency.

Organizers

Frédéric Koessler (CNRS, HEC Paris), frederic.koessler[at]gmail[dot]com

Maël Letreust  (CNRS,  IRISA Rennes), mael.le-treust[at]cnrs[dot]fr

Chantal Marlats (LEMMA, Université Paris Panthéon-Assas), chantal.marlats[at]u-paris2[dot]fr

Yannick Viossat (CEREMADE, PSL), viossat[at]ceremade[dot]dauphine[dot]fr

To join (or unsuscribe from) our mailing list, please contact Chantal Marlats at chantal.marlats[at]assas-universite[dot]fr. 

Former organizers

Joseph Abdou; Bernard De Meyer; Françoise Forges; Olivier Gossner;  Marie Laclau; Rida Laraki; Lucie Ménager; Vianney Perchet; Jérôme Renault; Dinah Rosenberg; Sylvain Sorin; Tristan Tomala; Xavier Venel; Nicolas Vieille; Guillaume Vigeral; Bruno Ziliotto