While patent litigation is an important appropriability mechanism for protecting firms’ proprietary knowledge, through the litigation process, valuable knowledge may unintentionally spill over from firms defending their patents to those they accuse of patent infringement. We examine whether such spillover subsequently enhances the innovation of accused firms by analyzing over 3000 patent litigation cases from 1998 through 2015 in the U.S. pharmaceutical industry. We find that firms accused of infringement have higher levels of innovation following litigation relative to other similar firms. Furthermore, litigation of patents that build on recent and heterogeneous knowledge and those of greater scope more strongly enhanced the accused firms’ subsequent innovation. These findings support the argument that patent litigation can facilitate knowledge spillover.

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门内有特洛伊木马？专利诉讼中的知识溢出

虽然专利诉讼是保护企业专有知识的重要专有机制，但在诉讼过程中，有价值的知识可能会无意中从捍卫其专利的企业溢出到他们指控专利侵权的人身上。我们通过分析 1998 年至 2015 年美国制药行业的 3000 多起专利诉讼案件来检验这种溢出效应是否会随后增强被控公司的创新。我们发现，与其他类似公司相比，被指控侵权的公司在诉讼后具有更高的创新水平。此外，建立在新知识和异质知识基础上的专利诉讼以及更大范围的专利诉讼更能有力地促进被控公司的后续创新。