IDENTIFYING THE AGE PROFILE OF PATENT CITATIONS: NEW ESTIMATES OF KNOWLEDGE DIFFUSION

被引：63

作者：

Mehta, Aditi ^{[2
]}

Rysman, Marc ^{[3
]}

Simcoe, Tim ^{[1
]}

机构：

[1] Univ Toronto, Joseph L Rotman Sch Management, Toronto, ON M5S 3E6, Canada

[2] US Dept Justice, Washington, DC 20530 USA

[3] Boston Univ, Dept Econ, Boston, MA 02215 USA

来源：

JOURNAL OF APPLIED ECONOMETRICS | 2010年 / 25卷 / 07期

关键词：

SPILLOVERS; FLOWS; MODELS;

D O I：

10.1002/jae.1086

中图分类号：

F [经济];

学科分类号：

02 ;

摘要：

Previous research studies the age profile of patent citations to learn about knowledge flows over time. However, identification is problematic because of the collinearity between application year, citation year, and patent age. We show empirically that a patent's 'citation clock' does not start until it issues, and propose a highly flexible identification strategy that uses the lag between application and grant as a source of exogenous variation. We examine the potential bias if our assumptions are incorrect, and discuss extensions into other research areas. Finally, we use our method to re-examine prior results on citation age profiles of patents from different technological fields and application year cohorts. Copyright (C) 2009 John Wiley & Sons, Ltd.

引用

页码：1179 / 1204

页数：26