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  <title>EconStor Community: Center for Mathematical Economics (IMW), Bielefeld University</title>
  <link rel="alternate" href="https://hdl.handle.net/10419/43753" />
  <subtitle>Center for Mathematical Economics (IMW), Bielefeld University</subtitle>
  <id>https://hdl.handle.net/10419/43753</id>
  <updated>2026-04-29T02:53:47Z</updated>
  <dc:date>2026-04-29T02:53:47Z</dc:date>
  <entry>
    <title>Regulation in a mean-field investment game with climate damage</title>
    <link rel="alternate" href="https://hdl.handle.net/10419/318521" />
    <author>
      <name>Aïd, René</name>
    </author>
    <author>
      <name>Federico, Salvatore</name>
    </author>
    <author>
      <name>Ferrari, Giorgio</name>
    </author>
    <author>
      <name>Rodosthenous, Neofytos</name>
    </author>
    <id>https://hdl.handle.net/10419/318521</id>
    <updated>2025-06-03T07:29:08Z</updated>
    <published>2025-01-01T00:00:00Z</published>
    <summary type="text">Title: Regulation in a mean-field investment game with climate damage
Authors: Aïd, René; Federico, Salvatore; Ferrari, Giorgio; Rodosthenous, Neofytos
Abstract: We study the problem of optimal investment in brown (carbon-intensive) production amid climate change and the impact of rising global temperatures. Our approach is based on a mean-field model of firms that produce goods whose productivity is adversely affected by temperature-related damages, which are in turn linked to the global stock of greenhouse gas (GHG) emissions. Each firm controls its investment rate in view of increasing its capital stock, which evolves stochastically due to idiosyncratic Gaussian shocks and is subject to exponential depreciation in the absence of investment. Firms aim to maximize their expected discounted profits, net of investment costs, by choosing investment strategies that respond to the level of aggregate GHG emissions and their adverse impact. We constructively establish the existence and uniqueness of a mean-field equilibrium, by characterising it as the unique solution to a bespoke three-dimensional system of forward-backward ordinary differential equations. This characterisation enables the implementation of the model to support numerical analyses for exploring the implications of climate damage on equilibrium outcomes and policy design in terms of taxes and phase-out dates for brown production.</summary>
    <dc:date>2025-01-01T00:00:00Z</dc:date>
  </entry>
  <entry>
    <title>The Maschler-Perles-Shapley value for taxation games</title>
    <link rel="alternate" href="https://hdl.handle.net/10419/318483" />
    <author>
      <name>Rosenmüller, Joachim</name>
    </author>
    <id>https://hdl.handle.net/10419/318483</id>
    <updated>2025-06-03T07:29:12Z</updated>
    <published>2025-01-01T00:00:00Z</published>
    <summary type="text">Title: The Maschler-Perles-Shapley value for taxation games
Authors: Rosenmüller, Joachim
Abstract: We continue the discussion of the taxation game following our presentation in [12]. Our concept describes a cooperative game played between a set of jurisdictions (" countries"). These players admit the operation of a multinational enterprise (MNE, the "firm") within their jurisdiction. The original version of this game is due to W. F. Richter [3],[4]. We suggest an extension of the model by introducing the dual game of the firm's profits and the tax function game. The latter is the NTU game generated by introducing tax functions (the term "tariffs" will be avoided henceforth). In [12] we treated the bargaining situation obtained when all countries decide to cooperate - otherwise everyone will fall back on their status quo point. However, in his basic paper, Richter argues that the share of the tax basis allotted to a country should be determined by the Shapley value of the taxation game. This idea establishes an interesting new field of applications. The Shapley value "as a tool in theoretical economics" [13], [14] has widely been applied in Game Theory, Equilibrium Theory, applications to Cost Sharing problems, Airport Landing Fee games, and many others. Based on these ideas, we continue our presentation by formulating the tax function game for the countries involved and introducing the Maschler-Perles-Shapley value as developed in [11]. To this end, we introduce the adjusted TU game, which reflects a rescaling of utility measurement as suggested by the superadditivity axiom of the Maschler-Perles solution. Then the Maschler-Perles-Shapley value of the tax function game is the image of the Shapley value of the adjusted TU game on the Pareto surface of the grand coalition. We demonstrate that the Maschler-Perles-Shapley value for the tax function game is Pareto efficient, covariant with affine transformations of utility, and anonymous.</summary>
    <dc:date>2025-01-01T00:00:00Z</dc:date>
  </entry>
  <entry>
    <title>Stationary mean-field games of singular control under Knightian uncertainty</title>
    <link rel="alternate" href="https://hdl.handle.net/10419/318549" />
    <author>
      <name>Ferrari, Giorgio</name>
    </author>
    <author>
      <name>Tzouanas, Ioannis</name>
    </author>
    <id>https://hdl.handle.net/10419/318549</id>
    <updated>2025-06-03T07:28:53Z</updated>
    <published>2025-01-01T00:00:00Z</published>
    <summary type="text">Title: Stationary mean-field games of singular control under Knightian uncertainty
Authors: Ferrari, Giorgio; Tzouanas, Ioannis
Abstract: In this work, we study a class of stationary mean-field games of singular stochastic control under model uncertainty. The representative agent adjusts the dynamics of an Itô-diffusion via onesided singular stochastic control, aiming to maximize a long-term average expected profit criterion. The mean-field interaction is of scalar type through the stationary distribution of the population. Due to the presence of uncertainty, the problem involves the study of a stochastic (zero-sum) game, where the decision maker chooses the 'best' singular control policy, while the adversarial player selects the 'worst' probability measure. Using a constructive approach, we prove existence and uniqueness of a stationary mean-field equilibrium. Finally, we present an example of mean-field optimal extraction of natural resources under uncertainty and we analyze the impact of uncertainty on the mean-field equilibrium.</summary>
    <dc:date>2025-01-01T00:00:00Z</dc:date>
  </entry>
  <entry>
    <title>Welfare effects of a concealed information exchange</title>
    <link rel="alternate" href="https://hdl.handle.net/10419/318448" />
    <author>
      <name>Müller, Lars</name>
    </author>
    <author>
      <name>Karos, Dominik</name>
    </author>
    <id>https://hdl.handle.net/10419/318448</id>
    <updated>2025-06-03T07:28:27Z</updated>
    <published>2025-01-01T00:00:00Z</published>
    <summary type="text">Title: Welfare effects of a concealed information exchange
Authors: Müller, Lars; Karos, Dominik
Abstract: This paper analyzes the welfare effects of private and unilateral disclosure of sensitive information in a sequential bargaining context. We consider a model where two sellers each propose a take-it-or-leave-it price for a homogeneous good to a single buyer. The buyer accepts or rejects the first seller's offer before the second seller proposes her price. Crucially, the second seller might learn the first seller's price and whether it was accepted, allowing her to update her belief about the buyer's willingness to pay and optimize her pricing strategy. The welfare effects caused by this information exchange are evaluated under general conditions. We show that it benefits the buyer if a rejection is revealed but might harm him if an acceptance is revealed. Additionally, the information exchange improves the societal welfare by reducing inefficiencies and promoting additional trade. This paper strengthens the theoretical framework for assessing the welfare effects of information exchanges by offering new insights and providing tools to assess causality for alleged damages.</summary>
    <dc:date>2025-01-01T00:00:00Z</dc:date>
  </entry>
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