Archives 2024-2025
Archives 2024-2025
September 12th : Yossi Spiegel (Coller School of Management, Tel Aviv University)
Title : A Dynamic Model of Predation
Location and time: This session is organized jointly with the reading group "Networks and Games" note that it takes place on Thursday, 3 pm and the location is the conference room on the 6th floor at the Maison des Sciences Economiques.
Summary: Growing concern about the market power of big tech giants has led to renewed interest in predatory behavior. We study the feasibility and profitability of predation in a dynamic environment, using a parsimonious infinite- horizon, complete information setting in which an incumbent repeatedly faces potential entry. When a rival enters, the incumbent chooses whether to ac- commodate or predate it; the entrant then decides whether to stay or exit. We show that there always exists a Markov perfect equilibrium, which can be of three types: accommodation, monopolization, and recurrent predation. We then analyze and compare the welfare e§ects of di§erent antitrust policies.
September 20th : Konstantinos V. Katsikopoulos (University of Southampton)
Title : Cognitive Operations: Models that Open the Black Box and Predict our Decisions
Location: Maison des Sciences Économiques, room S17
Summary: Improving human behavior requires first understanding it. Can mathematical models help provide such understanding? Yes. Cognitive Operations performs a systematic examination of two main approaches to modeling human decision making: optimization and simple heuristics. The approaches are discussed by focusing on general types of decisions—under risk, under uncertainty, strategic interaction and inventory control—and by drawing on economics, psychology and artificial intelligence. Cognitive Operations is committed to supporting academics and practitioners who seek to select a modeling approach that suits the operational decision at hand. It shows how to build models and employs clear criteria for assessing them. For a model to open the black box it must specify the cognitive processes that lead to the observed decisions. To predict decisions means to fix a model in one context and to test it in another. The comparative assessment of optimization and heuristic models serves scientific pluralism and leads to surprising insights. The studies in Cognitive Operations zoom in on bounded rationality, a field pioneered by Herb Simon, a founder of behavioral economics, cognitive psychology as well as artificial intelligence. They are useful complements to mathematical, conceptual and empirical studies of human decision making. It is possible to open the black box and predict our decisions.
September 27th: Evan Piermont (Royal Holloway, University of London )
Title : Modeling the Modeler: A Normative Theory of Experimental Design
Location: Maison des Sciences Économiques, room S17
Summary: We consider an analyst whose goal is to identify a subject’s utility function through revealed preference analysis. We argue the analyst’s preference about which experiments to run should adhere to three normative principles: The first, Structural Invariance, requires that the value of a choice experiment only depends on what the experiment may potentially reveal. The second, Identification Separability, demands that the value of identification is independent of what would have been counterfactually identified had the subject had a different utility. Finally, Information Monotonicity asks that more informative experiments are preferred. We provide a representation theorem, showing that these three principles characterized Expected Identification Value maximization, a functional form that unifies several theories of experimental design. We also study several special cases and discuss potential applications.
October 11th : Nicola Botta (Pottsdam Institute for Climate impact research )
Title : Trustable Pareto optimal controls with FP
Location: Maison des Sciences Économiques, room S17
Summary: We combine numeric and symbolic methods to accelerate first-principles simulations and enable optimisation of fusion confinement designs, building a reliable and versatile toolset for performance optimisation of strongly coupled physical systems with a large parameter space, and apply it to explore reliable fusion designs.”
November 29th: Erwin Ooghe (KU Leuven)
Title : Fairness gaps for earnings tax design
Location: Maison des Sciences Économiques, room S17
Summary: In a setting with skill and preference heterogeneity, we characterize a family of social welfare measures that aggregate fairness gaps, dened as the dierence between the money-metric utilities that individuals have and the money-metric utilities they should have in a fair society. Each welfare measure can be decomposed into government revenues (size), excess burden (ineciency), and unfair inequality (inequity). As a proof of concept, we evaluate four hypothetical earnings tax reforms based on two normative parameters: the degree of unfairness aversion and the degree of compensation for productive skills.
December 6th : Zoi Terzopoulou (GATE)
Title : TBA
Location: Maison des Sciences écoomiques, room S17
Summary: TBA
December 13th : Marcello Bassili (DEPS, University of Sienna )
Title : A new approach for imprecise probabilities
Location: Maison des Sciences Économiques, room S17
Summary: This paper introduces a novel concept of interval probability measures that enables the representation of imprecise probabilities, or uncertainty, in a natural and coherent manner. Within an algebra of sets, we introduce a notion of weak complementation denoted as ψ. The interval probability measure of an event H is defined with respect to the set of indecisive eventualities (ψ(H))c, which is included in the standard complement Hc.We characterize a broad class of interval probability measures and de- fine their properties. Additionally, we establish an updating rule with respect to H, incorporating concepts of statistical independence and de- pendence. The interval distribution of a random variable is formulated, and a corresponding definition of stochastic dominance between two ran- dom variables is introduced. As a byproduct, a formal solution to the century-old Keynes-Ramsey controversy is presented.
January 31st : Georges Zaccour (GERAD, HEC Montreal, Canada)
Title : Payment schemes for finitely repeated Prisoner's Dilemma games
Location: Maison des Sciences Économiques, room S17
Summary
We consider finitely repeated Prisoner's Dilemma game and propose a method of sustaining cooperation as an ε-equilibrium in limited retaliation behavior strategies. The main feature of this strategy is that the punishment of a deviated player does not necessarily last until the end of the game. The duration of punishment depends on the stage when deviation happens, and it is not uniquely defined. We propose two payment schemes along the cooperative trajectory to sustain cooperation based on these limited retaliation strategies. If the payments in the game are organized following these schemes, when they exist, then players have no incentive to deviate and cooperation is sustainable.
February 7th :Michel Grabisch (Centre d'Economie de la Sorbonne)
Title : A polynomial view of TU-games
Location: Maison des Sciences Économiques, room S17
Summary: We propose in this paper a polynomial representation of TU-games, and more generally set functions on a finite set. Our representation needs a countably infinite set of players and the natural ordering of finite sets of N, defined recursively. For a given basis of the vector space of games, we associate to each game v a formal polynomial of degree at most 2^n-1 whose coefficients are the coordinates of v in the given basis. By the fundamental theorem of algebra, v can be represented by the roots of the polynomial. We present some new families of games stemming from this polynomial context, like the irreducible games, the multiplicative games and the cyclotomic games.