International Society on Dynamic Games

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May 6, 2021

Dynamic Games and Applications Seminar

 

May 6, 2021 11:00 AM – 12:00 PM (Montreal Time, UTC -4)

Buyer direct financing under supplier disruption risk

Xiao Huang – John Molson School of Business, Concordia University, Canada

Xiao Huang

Webinar link
Webinar ID: 881 6070 4034
Passcode: 095916

We consider a dyadic supply chain in which a large and creditworthy buyer procures from a capital-constrained supplier subject to disruption risk. The buyer may offer direct financing (BDF) to the supplier with customized payment terms (PE) and tailored interest rates (TR). We analyze the value and interplay of these elements by characterizing equilibrium contractual terms under several BDF contracts with different PE and TR potentials.

Published by Sergey Kumkov
April 28, 2021

Dynamic Games and Applications Seminar

Apr 29, 2021 11:00 AM – 12:00 PM (Montreal time, UTC -4)

Team collaboration in innovation contests

Sidika Tunc Candogan – School of Management, University College London, United Kingdom

Sidika Tunc Candogan

Webinar link
Webinar ID : 962 7774 9870
Passcode : 285404

 

In an innovation contest, an organizer elicits solutions to an innovation-related problem from a group of solvers. Although solvers are capable of developing individual solutions and making individual submissions, if the organizer encourages collaboration, solvers may collaborate as teams and make team submissions. Motivated from different policies adopted by various crowdsourcing platforms (e.g., InnoCentive, Topcoder, and 99designs), we identify conditions under which the organizer can benefit from team submissions. By examining equilibrium outcomes of a game-theoretic model, we show that when the organizer seeks high-novelty solutions to a nondecomposable problem (e.g., design challenges at InnoCentive), the organizer can benefit from team submissions despite the decrease in solvers’ efforts. Yet, when the organizer seeks low-novelty solutions to a nondecomposable problem (e.g., logo design challenges at 99designs), the organizer may not benefit from team submissions. We further show that when the organizer seeks low-novelty or high-novelty solutions to a decomposable problem (e.g., software challenges at Topcoder), the organizer can benefit from team submissions, but under some conditions. Finally, we also analyze when solvers can benefit from collaborating as teams because the organizer’s benefit from team submissions hinges upon solvers’ decisions. We show that unless there emerges synergy within teams, solvers can benefit from collaborating as teams because collaboration reduces solvers’ incentive to exert effort.

Published by Sergey Kumkov
April 22, 2021

Dear Colleagues,

 

Dynamic Games and Applications is planning the following special issues:

 

Modeling and Control of Epidemics

Guest Editors: Quanyan Zhu, Elena Gubar, Eitan Altman

Submission Deadline: extended to June 15, 2021

 

Dynamic Games and Social Networks

Guest Editors: Ennio Bilancini, Leonardo Boncinelli, Paolo Pin, Simon Weidenholzer

Submission Deadline: June 30, 2021  

 

Multi-agent Dynamic Decision Making and Learning

Guest editors:  Konstantin Avrachenkov, Vivek S. Borkar, U. Jayakrishnan Nair

Submission Deadline: June 30, 2021 

 

Dynamic Games in Environmental Economics and Management

Guest Editors: Ngo Van Long, Florian Wagener

Submission Deadline: June 30, 2021

 

Learning and Computations in Games & Economics

Guest Editors: Mehryar Mohri, Vianney Perchet

 

Submission Deadline: October 15, 2021

Published by Sergey Kumkov
April 19, 2021

Dynamic Games and Applications Seminar

Apr 22, 2021 11:00 AM – 12:00 PM (Montreal time, UTC -4)

Interdiction games on graphs

Margarida Carvalho – Department of Computer Science and Operations Research, Université de Montréal, Canada

Margarida Carvalho

Webinar link
Webinar ID: 962 7774 9870
Passcode: 285404

 

In integer programming games, players' feasible strategies are described by lattice points inside polyhedra. This game representation is natural when players' decisions have integrality restrictions. In this talk, we will start by presenting practical examples of integer programming games. Then, we will focus on a particular "dynamic" integer programming game played over a graph, the Multilevel Critical Node problem. Besides a discussion on the problem difficulty, we will describe an exact cutting plane algorithm to determine the game equilibrium and a reinforcement learning based heuristic to approximate it.

Published by Sergey Kumkov
April 12, 2021

ISS Informal Systems Seminar

Apr 16, 2021 02:00 PM – 03:00 PM (Eastern Daylight Time, UTC -4)

Epidemic spread with transportation: Modeling, inference, and control

 

Philip E. Paré – Purdue University, United States

Philip E. Paré

Webinar link
Webinar ID: 910 7928 6959
Passcode: VISS

 

In this talk, we explore how networked compartmental models of epidemic processes combined with transportation data can be used to model the spread of COVID-19. We first employ a networked SEIR (susceptible-exposed-infected-recovered) model and present necessary and sufficient conditions for identifying the model parameters from data. We illustrate several shortcomings of traditional approaches by applying the identification results to COVID-19 testing and travel data from the Northeastern United States and use these inaccuracies as motivation for the latter two parts of the talk. One typical error is assuming that testing data perfectly capture the underlying epidemic states, which is not accurate due to delays in testing results, testing inaccuracies, and biased/partial population sampling. We present an algorithm for inferring the underlying epidemic states of an SIR model from testing data that accounts for heterogeneous delays and a closed-form expression for the error of the algorithm. The last part of the talk focuses on the recent development of a networked SEIR model that incorporates population flow as the viral spread mechanism to capture infection transmission between sub-populations. We show, under reasonable assumptions, that the dynamics have a consensus-type behavior where in steady-state each sub-population has the same amount of recovered individuals. Employing this model, we present several approaches for using travel restrictions as a control mechanism.

Published by Sergey Kumkov
April 12, 2021

Dynamic Games and Applications Seminar

Apr 15, 2021 11:00 AM – 12:00 PM (Eastern Daylight Time, UTC -4)

Investment in cleaner technologies in a transboundary pollution dynamic game. A numerical investigation

 

Guiomar Martín-Herrán –Departamento de Economía Aplicada, Universidad de Valladolid, Spain

Guiomar Martín-Herrán

Webinar link
Webinar ID: 962 7774 9870
Passcode: 285404

Within a non-cooperative transboundary pollution dynamic game, we study the strategic impact of a region's investment in the adoption of a cleaner technology, as embodied by a reduction in the emission per output ratio, on the equilibrium outcomes and regions' welfare. The ratio of emissions to output is endogenous and is a decreasing function of the level of the stock of clean technology. Each region can invest in a clean technology in addition to its control of emissions. Clean technology is assumed to be public knowledge so that both regions benefit from the investment in clean technology of an individual region. Pollution damage is modelled as a strictly convex function in the pollution stock. We analyze the feedback equilibrium of the non-cooperative game between two regions played over an infinite horizon. The formulation of the transboundary pollution dynamic game does not fit any special structure of analytically tractable games such as linear-state or linear-quadratic differential games. We develop numerical methods to characterize the feedback equilibrium of the non-cooperative game between two regions. The equilibrium trajectories of the stock of pollution and stock of clean technology as well the regions' welfare are compared under different scenarios.

 

(jointly with Javier de Frutos and Paula M. López-Pérez).

Published by Sergey Kumkov
April 7, 2021

ISS Informal Systems Seminar

Apr 9, 2021 10:00 AM – 11:00 AM (Eastern Daylight Time, UTC -4)

Mean-field and graph limits for collective dynamics models with time-varying weights

Nathalie Ayi – Jacques-Louis Lions Laboratory, Sorbonne University, France

Nathalie Ayi

Webinar link
Webinar ID: 910 7928 6959
Passcode: VISS

In this work, we study a model for opinion dynamics where the influence weights of agents evolve in time via an equation which is coupled with the opinions’ evolution. We explore the natural question of the large population limit with two approaches: the now classical mean-field limit and the more recent graph limit. After establishing the existence and uniqueness of solutions to the models that we will consider, we provide a rigorous mathematical justification for taking the graph limit in a general context. Then, establishing the key notion of indistinguishability, which is a necessary framework to consider the mean-field limit, we prove the subordination of the mean-field limit to the graph one in that context. This actually provides an alternative (but weaker) proof for the mean-field limit. We conclude by showing some numerical simulations to illustrate our results.

 

Bio: Nathalie Ayi is an Assistant Professor at the Jacques Louis Lions laboratory at Sorbonne University (Paris). Before joining this laboratory, she was a post-doctoral fellow in the IPSO INRIA team at Rennes. She received her PhD degree in Mathematics from the University of Nice Sophia-Antipolis in 2016. Her field of research is partial differential equations with a specific interest in kinetic theory and the study of scaling limits.

Published by Sergey Kumkov