The Small World of Corporate Boards
用图论分析美、英、德三国公司董事会网络，发现随机图模型能很好解释其结构，董事会并不比随机情况更“小圈子”，且存在正度相关：忙碌董事倾向于共事。
Abstract: We demonstrate the importance of graph theory for understanding boards of directors. Specifically, we focus on the ‘small world’ phenomenon. Our empirical results show that a random graph model is remarkably good at explaining board structure and connectedness in the United States, the United Kingdom and Germany. Although there are small‐world traits such as ‘clustering’ and ‘short‐paths’ in the corporate world, they are no more pronounced than would be expected by chance in a statistically similar, but randomly assembled corporate universe. In short, boards of directors, especially in the United States, are no more ‘clubby’ than expected. Finally, our results show the existence of positive degree correlation: directors who sit on many boards do so in the company of other directors who sit on many boards. Board members whose services are in high demand, serve on boards with similar directors.