Empirical investor networks (EIN) proposed by Ozsoylev et al. are assumed to capture the information spreading path among investors. Here, we perform a comparative analysis between the EIN and the cellphone communication networks (CN) to test whether EIN is an information exchanging network from the perspective of the layer structures of ego networks. We employ two clustering algorithms (k-means algorithm and \(H/T\) break algorithm) to detect the layer structures for each node in both networks. We find that the nodes in both networks can be clustered into two groups, that one has a layer structure similar to the theoretical Dunbar Circle that alters in ego networks exhibit a four-layer hierarchical structure with the cumulative number of 5, 15, 50 and 150 from the inner layer to the outer layer, and the other one has an additional inner layer with about 2 alters compared with the Dunbar Circle. We also find that the scale ratios, which are estimated based on the unique parameters in the theoretical model of layer structures, conform to a log-normal distribution for both networks. Our results not only deepen our understanding on the topological structures of EIN, but also provide empirical evidence of the channels of information diffusion among investors.

中文翻译：

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实证投资者网络和手机通讯网络中分层结构的比较分析

Ozsoylev等人提出的经验投资者网络（EIN）。假定捕获了投资者之间的信息传播路径。在这里，我们从自我网络的层结构的角度对EIN和手机通信网络（CN）进行比较分析，以测试EIN是否是信息交换网络。我们采用两种聚类算法（k-均值算法和\（H / T \）中断算法）以检测两个网络中每个节点的层结构。我们发现，两个网络中的节点都可以分为两组，一个具有类似于理论上的邓巴圆环的层结构，自我网络中的变化显示出四层的层次结构，其累积数为5、15、50和从内层到外层的距离为150，而另一层与Dunbar Circle相比，其内层具有大约2个变化。我们还发现，基于层结构理论模型中唯一参数估算的比例比符合两个网络的对数正态分布。我们的结果不仅加深了我们对EIN拓扑结构的理解，而且为投资者之间的信息传播渠道提供了经验证据。