Natural concentration in industrial research collaboration
研究寡头市场中研发合作网络的集中现象，发现当合作成本较高时，集中是高效网络的典型特征，且现实网络可能集中度不足。
Empirical work shows that networks of research and development alliances are asymmetric, with a small number of firms involved in the majority of partnerships. This article investigates the welfare-relevant effects of such concentrated networks in a model of network formation in an oligopolistic market. We find that concentration is a typical characteristic of a socially efficient network when the costs of collaborative activity are significant. Moreover, expanding on prior work relating to strategically stable interfirm networks, we compare the stable and the efficient structures. Our findings suggest that real-world networks might even exhibit too little concentration.