This paper focuses on cooperation among organizations in a common‐pool resource (CPR) problem situation. Cooperation is particularly challenging in settings where resource degradation is produced by a variety of different sectors and parts of the population; and where the problem, as well as public responsibilities, transcend borders and jurisdictions. Focusing on transboundary water quality management in the Rhine catchment area, we ask: What drives two actors in a CPR problem situation to cooperate with each other? We argue that the degree of threat to a CPR is an important driver for collective action, and focus on actors' exposure to and perception of a threat to a CPR. Furthermore, we rely on applications of the ecology of games framework (EGF), taking into account the larger institutional context of CPR management. This allows us to test whether actors' participation in forums, such as regional and international water body associations, helps to overcome the CPR problem by further enhancing interactions among actors. Based on survey data and applying advanced network statistics (exponential random graph models [ERGM]), we conclude that although problem exposure is one factor that enhances joint cooperation, participation in forums plays an even bigger role for cooperation in a CPR problem setting. Our study contributes to research on cooperation in CPR problem settings, highlights the need to more systematically include the effects that CPR problems have on actors when analyzing CPR problem settings, and stresses the function of forums as triggers for cooperation in CPR problem situations.

本文重点关注公共池塘资源（CPR）问题下的组织合作。当资源退化的“始作俑者”来自各类不 同群体，且CPR问题和公共责任超越了司法管辖范围时，合作会很困难。我们将焦点放在莱茵河流域 的水质管理上，并提出如下问题：在面临CPR问题的情况下，什么因素会驱动两个行为者进行合作？ 我们认为，对CPR的威胁是集体行动的驱动因素，因此，我们关注了行为者对CPR威胁的接触以及感 知。我们依赖于生态博弈框架（EGF），来考虑CPR管理背后更大的制度背景。我们检验了行为者参与 论坛是否会有助于增强行为者之间的互动，进而克服CPR问题。根据调查数据，我们采用了社会网 络高级统计分析方法（指数随机图模型，ERGM），并得出结论：对威胁问题的接触可以促进共同合 作；此外，参与论坛对于CPR问题环境下的合作更为重要。该研究有助于对CPR问题环境下的合作进 行探索，突出了在分析CPR问题时系统考虑其对行为者的影响的必要性，并强调了论坛引发合作的 这一功能。