Econ Papers Daily / 期刊论文
具有扩散激励的内生网络形成
Endogenous network formation with diffusion incentives
摘要
This paper proposes a non-cooperative game of network formation in which creating access to the network – for oneself and others – is a public good. Link formation therefore reflects a trade-off between the social value of links and their private cost. The paper characterizes the architecture of strict Nash networks. Strict Nash equilibria are either flat or hierarchical. Flat equilibria consist of a wheel (i.e., a directed cycle) that may or may not encompass all agents. Hierarchical equilibria are trees in which some agents act as intermediaries between otherwise disconnected groups. When the cost of link formation is sufficiently low, the exhaustive wheel is the unique equilibrium architecture and best-response dynamics converge to it with probability one. For intermediate costs, multiple equilibrium architectures coexist and can be Pareto-ranked: the exhaustive wheels dominate the non-exhaustive ones and the empty network, and trees dominate the empty network.
中文摘要
本文提出了一种网络形成的非合作博弈模型，在该模型中，为自己及他人创建网络接入具有公共品属性。因此，链接形成反映了链接的社会价值与其私人成本之间的权衡。本文刻画了严格纳什网络的架构特征。严格纳什均衡要么是扁平结构，要么是层级结构。扁平均衡由轮状结构（即有向环）构成，该结构可能包含所有参与者，也可能不包含。层级均衡则呈现树状结构，其中部分参与者充当原本互不相连群体之间的中介。当链接形成成本足够低时，全覆盖轮状结构是唯一的均衡架构，且最优反应动态以概率1收敛于此结构。在中等成本条件下，多种均衡架构并存且可进行帕累托排序：全覆盖轮状结构优于非全覆盖轮状结构及空网络，而树状结构优于空网络。