We investigate the stability of cooperation agreements, such as those agreed by cartels, among firms in a Cournot model of oligopolistic competition embedded in a multimarket contact setting. Our analysis considers a broad array of 64 potential market structural configurations under linear demand and quadratic production costs. We establish that for an appropriate range of parameter values there exists a unique core stable market configuration in which an identical two‐firm cartel is sustained in both markets. Our result highlights the significance of multimarket presence for cartel formation in light of the well‐known result from the single‐market setting where cartels are non‐profitable.

中文翻译：

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卡多多国寡头垄断市场的稳定性

我们以嵌入多市场联系环境中的Cournot寡头竞争模型研究企业之间合作协议（如卡特尔达成的协议）的稳定性。我们的分析考虑了线性需求和二次生产成本下的64种潜在市场结构配置。我们确定，对于适当范围的参数值，存在一个独特的核心稳定市场配置，其中两个市场都维持相同的两个公司卡特尔。鉴于卡特尔无利可图的单一市场环境中的著名结果，我们的结果突出了多市场存在对卡特尔形成的重要性。