中文摘要
本文直接检验不同企业发明者之间的互动驱动知识溢出的假说。我构建了一个上市公司网络，其中每条连边都是两家企业的发明者中在这两个组织均有以往专利合作伙伴的发明者所占相对比例的函数。我使用这一测度，对各企业开展的研发对其网络关联企业的生产率和创新结果的影响进行加权。实证分析中的一个问题是，所得估计可能反映了同时决定企业绩效、网络连接和外部研发的未观测因素。我采用一种受企业互动博弈论模型启发的创新性工具变量（IV）策略来解决这一问题。我以网络空间中距离足够远的其他企业的研发，作为与某一企业相连接的企业的研发的工具变量。利用所得的溢出效应估计，我计算出，在接入该网络的企业中，研发的边际社会回报约为边际私人回报的112%。
Abstract
Abstract In this article, I directly test the hypothesis that interactions between inventors of different firms drive knowledge spillovers. I construct a network of publicly traded companies in which each link is a function of the relative proportion of two firms’ inventors who have former patent collaborators in both organizations. I use this measure to weigh the impact of R&D performed by each firm on the productivity and innovation outcomes of its network linkages. An empirical concern is that the resulting estimates may reflect unobserved, simultaneous determinants of firm performance, network connections, and external R&D. I address this problem with an innovative IV strategy, motivated by a game-theoretic model of firm interaction. I instrument the R&D of one firm’s connections with that of other firms that are sufficiently distant in network space. With the resulting spillover estimates, I calculate that among firms connected to the network the marginal social return of R&D amounts to approximately 112% of the marginal private return.