Firms in inter-organizational networks such as supply chains or strategic alliances are exposed to interdependent risks. These are risks that are transferable across partner firms. They can be decomposed into intrinsic risks a firm faces from its own operations and extrinsic risks transferred from its partners. Firms broadly have access to two security strategies: either they can independently eliminate both intrinsic and extrinsic risks by securing their links with partners, or alternatively, firms can cooperate with partners to eliminate sources of intrinsic risk in the network. We develop a graph-theoretic model of interdependent security and demonstrate that the network-optimal security strategy can be computed in polynomial time. Then, we use cooperative game-theoretic tools to examine whether and when firms can sustain the network-optimal security strategy via cost-sharing mechanisms that are stable, fair, computable, and implementable via a series of bilateral cost-sharing arrangements. We consider different informational assumptions in the network and show that, when the players know only their own costs, firms have a clear incentive to cooperate globally whereas, in the presence of public information, there may not exist cost-sharing mechanisms that can sustain network-wide cooperation. We then design a novel cost-sharing mechanism: the agreeable allocation, that is easy to compute, bilaterally implementable, ensures stability, and is fair in a well-defined sense. However, the agreeable allocation need not always exist. We then generalize levels of agreeable allocation, with weaker implementability properties but greater existence guarantees.

翻译：供应链或战略联盟等跨组织网络中的企业面临着相互依赖的风险，即可在合作伙伴企业间转移的风险。这些风险可分解为企业自身运营产生的内在风险，以及源自合作伙伴的外在风险。企业大致可采用两种安全策略：要么通过保障与合作伙伴的链路来独立消除内在和外在风险，要么与合作伙伴协作消除网络中的内在风险源。我们建立了相互依赖安全的图论模型，并证明网络最优安全策略可在多项式时间内计算。随后，我们运用合作博弈论工具，研究企业能否通过稳定、公平、可计算且可通过系列双边成本分摊安排实施的机制，维持网络最优安全策略。我们考虑了网络中的不同信息假设，表明当参与者仅知晓自身成本时，企业具有明确的全球合作动机；而在公共信息环境下，可能存在无法通过成本分摊机制维持全网合作的情况。我们设计了一种新型成本分摊机制——可接受分配，该机制易于计算、可双边实施、确保稳定性，且在严格意义上具有公平性。但可接受分配并非总是存在。我们进而推广了可接受分配水平，在保留较弱的可实施性属性前提下，增强了存在性保障。