International Society of Dynamic Games

  • Seminar: Lucia Sbragia

    Lucia Sbragia
    Durham University
    UK

    Seminar, Department of Decision Sciences, HEC Montreal

    International environmental agreements in the presence of adaptation and self-image

    April 30, 2024 11:00 AM — 12:00 PM (Montreal time)

    Zoom webinar link

    We examine the stability and effectiveness of an international environmental agreement when countries can decide both their emissions and adaptation levels. We assume that adaptation requires a prior irreversible investment and presents the characteristics of a private good by reducing a country’s vulnerability to the impact of pollution, while mitigation policies produce a public good by reducing the total amount of pollution. By using a stylized model capturing the main features of the Paris agreement, we show that investments in adaptation do not ameliorate the participation to the agreement, total emissions by countries are higher than when countries can only emit, and that global welfare is higher with adaptation than without. All this suggests that adaptation is beneficial even if there may be a loss in participation. We also investigate the impact of a regulated adaptation.

    (joint work with Michèle Breton)

  • DGA Seminar: Georges Zaccour

    Georges Zaccour
    Department of Decision Sciences HEC Montréal
    Canada

    Dynamic Games and Applications Seminar

    Dynamic Games Played over Event Trees with Coupling Constraints

    April 18, 2024 11:00 AM — 12:00 PM (Montreal time)

    Zoom webinar link

    In this talk, I will first present the framework of dynamic games played over event trees (DGPETs) and characterize Nash equilibrium in a setup where the players’ action sets are interdependent. Second, I will illustrate the theory with a model where a set of competing firms procure a product from the same supplier that faces a capacity constraint, including a possible complete shortage, which binds together the ordering strategies of the firms. Numerical results are discussed.
    (The second part is a paper with Elena Parilina and Stefan Wrzaczek.)

  • DGA Seminar: Michel Grabisch

    Michel Grabisch
    Université Paris 1
    France

    Dynamic Games and Applications Seminar

    On the design of public debate in social network

    April 11, 2024 11:00 AM — 12:00 PM (Montreal time)

    Zoom webinar link

    We propose a model of the joint evolution of opinions and social relationships in a setting where social influence decays over time. The dynamics are based on bounded confidence: social connections between individuals with distant opinions are severed while new connections are formed between individuals with similar opinions. Our model naturally gives raise to strong diversity, i.e., the persistence of heterogeneous opinions in connected societies, a phenomenon that most existing models fail to capture. The intensity of social interactions is the key parameter that governs the dynamics. First, it determines the asymptotic distribution of opinions. In particular, increasing the intensity of social interactions brings society closer to consensus. Second, it determines the risk of polarization, which is shown to increase with the intensity of social interactions. Our results allow to frame the problem of the design of public debates in a formal setting. We hence characterize the optimal strategy for a social planner who controls the intensity of the public debate and thus faces a trade-off between the pursuit of social consensus and the risk of polarization. We also consider applications to political campaigning and show that both minority and majority candidates can have incentives to lead society towards polarization.

    (with A. Mandel and A. Rusinowska).