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ELe séminaire se tient le lundi de 11h à midi, en général en salle 01 (rez-de-chaussée)
à l'Institut Henri Poincaré, 11 rue Pierre et Marie Curie, Paris 5ème. Plan


Sur cette page, vous trouverez les titres et les abstracts des séminaires du mois à venir.

Les noms des speakers des mois à venir se trouvent sur l'agenda.

Les abstracts des séances précédentes peuvent être trouvé sur la page suivante Archives 2016-??.


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The seminar takes place on monday morning from 11h to 12h, most of the time in Salle 01 (ground floor) at

Institut Henri Poincaré, 11 rue Pierre et Marie Curie, Paris 5ème. Plan


On this page, you will find the titles and the abstract for the seminar of the coming month.

The name of future speakers are displayed in the agenda.

The abstracts and the titles of the previous seminar can be found on the following page Archives 2016-??.


December 2019



Lundi 2 Décembre Alfred Galichon (New York University)
  • Title: The equilibrium flow problem and multivocal gross substitutes (joint with Larry Samuelson and Lucas Vernet).
    • Abstract We show that several classical economic models such as  two-sided matching models, min-cost flow problems, hedonic models, and dynamic programming problems are subcases of a more general class of problems called equilibrium flow problems. To analyze this problem, we introduce a novel notion of gross substitutes for correspondences called "multivocal gross substitutes". We show that this notion generalizes some familiar notions of substitutes (such as weak gross substitutes) while strengthening others (such as that of Kelso and Crawford).  Our main result, the inverse isotonicity theorem, establishes that if an excess supply correspondence satisfies multivocal gross substitutes, then the inverse correspondence is isotone in the strong set order, extending to the corresponding case results by Berry, Gandhi and Haile (2013). As another consequence, extend the lattice structure results of Demange and Gale (1985) to general networks beyond the bipartite case.

Lundi 9 Décembre Jose Correa (Universidad de Chile)
  • Title: On the Price of Anarchy for flows over time
    • Abstract : Dynamic network flows, or network flows over time, constitute an important model for real-world situations where steady states are unusual, such as urban traffic and the Internet. These applications immediately raise the issue of analyzing dynamic network flows from a game-theoretic perspective. In this paper we study dynamic equilibria in the deterministic fluid queuing model in single-source single-sink networks, arguably the most basic model for flows over time. In the last decade we have witnessed significant developments in the theoretical understanding of the model. However, several fundamental questions remain open. One of the most prominent ones concerns the Price of Anarchy, measured as the worst case ratio between the minimum
      time required to route a given amount of flow from the source to the  sink, and the time a dynamic equilibrium takes to perform the same task. Our main result states that if we could reduce the inflow of the  network in a dynamic equilibrium, then the Price of Anarchy is exactly e/(e − 1) ≈ 1.582. This significantly extends a result by Bhaskar, Fleischer, and Anshelevich (SODA 2011). Furthermore, our methods allow to determine that the Price of Anarchy in parallel-link networks is exactly 4/3. Finally, we argue that if a certain very natural monotonicity conjecture holds, the Price of Anarchy in the general case is exactly e/(e − 1).

      The talk is based on joint work with Andres Cristi and Tim Oosterwijk

Lundi 16 Décembre Christina Pawlowitsch (Université Panthéon-Assas, LEMMA)
  • Title: "Evolutionary dynamics of costly signaling" (joint with Josef Hofbauer)
    • Abstract :


      Costly-signaling games have a remarkably wide range of applications (education as a costly signal in the job market, handicaps as a signal for fitness in mate selection, politeness in language). The formal analysis of evolutionary dynamics in costly-signaling games has only recently gained more attention. In this paper, we study evolutionary dynamics in two basic classes of games with two states of nature, two signals, and two possible reactions in response to signals: a discrete version of Spence’s (1973) model and a discrete version of Grafen’s (1990) formalization of the handicap principle. We first use index theory to give a rough account of the dynamic stability properties of the equilibria in these games. Then, we study in more detail the replicator dynamics and to some extent the best-response dynamics.(joint with Josef Hofbauer)



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