社交网络视角下基于博弈论的信任机制研究

The integrity (honesty and credibility) level of social members is an important manifestation of the soft power and overall competitiveness of a country. At present, the contradiction between the social credit system construction and the level of economic development as well as the stage of social development is still outstanding. To push forward the modernization of national governance system and capacity, we urgently need to accelerate the construction of social credit system. At the micro level, obtaining trust among activity participants and conscientiously observing the contract are the prerequisites for the smooth operation of trading activities. In fact, there are various channels to achieve mutual trust. Under the heterogeneity of trust mechanism, traders have different needs for credit services. This subject intends to embed the social network theory into the trust game model and proposes the theoretical explanation on the differentiation of the trust mechanism. Based on Game Theory and concerned with the trading activities conducted by the trustor and trustee, it builds the trust game model; it lays special stress on analyzing the influence of the breadth and depth of the social network on the trust strategy adopted by activity executors under the social network theory framework, and it analyses the optimal strategy; starting from maximizing social welfare, it studies the characteristics of an efficient and stable trust mechanism under complex social networks. On this basis, it puts forward policy suggestions of optimizing the allocation of credit service resources and perfecting the credit service market, so as to better drive the improvement of social integrity.

社会成员的诚信水平是一个国家软实力和整体竞争力的重要体现。当前，社会信用体系建设与经济发展水平和社会发展阶段不适应的矛盾仍然突出。推进国家治理体系和治理能力现代化，迫切需要加快推动社会信用体系建设。从微观层面看，行动主体间取得信任并自觉遵守合约是交易活动顺利开展的前提。事实上，实现互信的渠道多样，在信任机制异质性作用下，交易者对信用服务产生了不同的需求。本课题拟将社交网络理论嵌入信任博弈模型中，提出信任机制差异化的学理解释。基于博弈论，围绕信托人和受托人开展的交易活动，建立信任博弈模型；重点分析在社交网络理论框架下，社交网络的广度、深度对行动主体采取信任策略的影响，分析交易者的最优策略；从社会福利最大化出发，研究复杂社交网络下高效、稳定的信任机制特征。在此基础上，提出优化信用服务资源配置、完善信用服务市场的政策建议，以此更好推动社会诚信水平提升。

本项目将社交网络理论嵌入信任博弈模型中，提出信任机制差异化的学理解释。基于博弈论，以融资问题背景下的贷款人-借款人的策略为出发点，分析了贷款人的社交网络结构对均衡和社会福利的影响，并提出优化信用服务资源配置、完善信用服务市场的政策建议。同时，本项目对贷款人-借款人的基准框架进一步的拓展，考虑了一般设定下的委托-代理模型最优解的存在性问题，区别于文献中对契约空间施加的先验拓扑限制性的假设条件，提出了该存在性一种更直观且易检验的充分必要条件，为进一步刻画最优解及分析其性质打下基础。按照此逻辑，同样在融资问题的背景下，考虑给定股权式拍卖模式，即出售不可分割的资产且竞标者拥有相互依赖的估值，本项目进一步研究了卖方在融资过程中优化问题的最优解的刻画，即刻画一种事后激励相容且个体理性的最优股权拍卖机制，并分讨论在一般对称和非对称情况下的实施机制（如内生异质性股权契约的英式拍卖）。