Abstract: In intermediated markets, intermediaries often focused on their own customer bases and were reluctant to share auction information with other intermediaries, which often led to information blockage and reduced allocation efficiency. Existing auction mechanisms in social networks incentivized information sharing through centralized designs, but required all participants to reveal private information to the seller, including intermediaries’ social connections and buyers’ valuations, thereby raising concerns about privacy leakage and seller manipulation. To address these issues, a decentralized information diffusion mechanism with transaction costs (DCIDM-TC) was proposed. The mechanism enabled agents to collaboratively complete allocation and payment without a central authority, while ensuring that intermediaries maintained private downstream links and that no participant had full network visibility. Theoretical analysis shows that the suggested strategy profile of DCIDM-TC constitutes an ex-post Nash equilibrium. In addition, for information blockage problem among intermediaries in the existing centralized information diffusion mechanism with transaction costs (IDM-TC), theoretical analysis and experimental results show that DCIDM-TC is completely consistent in outcome with IDM-TC executed on the shortest-path tree of the intermediated market, thereby providing a decentralized implementation for IDM-TC.

摘要： 中介市场中，中介因仅关注自身客户群体而不愿共享拍卖信息给其他中介群体，易导致信息闭塞并降低资源配置效率。现有的社交网络拍卖机制通过中心化方式激励中介共享信息，但要求所有参与者向卖家披露私有信息(中介的社交连接与买家的估值)，进而引发隐私泄露与卖家作弊风险。针对上述问题，提出一种具有交易成本的去中心化信息扩散机制(DCIDM-TC)。该机制通过参与者协同完成资源分配与支付过程，无需可信中心权威机构，并能保障中介下游连接关系的私有性，避免任何单一参与者获取完整的网络视图。理论分析证明，DCIDM-TC的建议策略组合构成事后纳什均衡。此外，针对现有中心化具有交易成本的信息扩散机制(IDM-TC)中存在的中介间信息闭塞问题，理论分析与实验结果表明，DCIDM-TC与中介市场最短路径树上执行的IDM-TC在结果上完全一致，从而为IDM-TC提供了一种去中心化实现方案。