专利对企业报酬生产率的作用效应估计与分解

Estimation and Decomposition of the Impact of Patents on Firms’ Revenue Productivity

本文拓展了已有的生产率估计方法,构建了一个包含内生生产率变化的计量框架来评估专利对报酬生产率的作用效应.该估计方法直接考虑了专利与研发投入对企业生产率的的影响,从而避免了常见的假定生产率是外生变动而导致的生产函数的估计偏误.为了深入探讨专利对生产率的作用机制,本文将专利对生产率的作用效应分解为垄断效应和规模效应.本文提出的估计框架可以广泛适用于评估和检验专利对报酬生产率的作用效应与作用机制.基于中国医药制造业2001–2007年的企业数据和专利数据的合并数据,本文考察了专利对于生产率的作用效应与机制.实证结果发现:第一,仅有滞后一期的发明专利对于未来的报酬生产率有显著的促进效应;第二,专利对报酬生产率的作用主要体现为物质生产率提高所带来的规模效应而非垄断效应.最后,本文进行了三方面的拓展研究并发现:专利补贴政策未能改善专利对报酬生产率的作用结果,专利审查能够有效地识别高质量的专利,私人企业的发明专利相对于非私人企业能够更显著地促进报酬生产率的提升.

This paper extends the existing estimation methods of productivity estimation and proposes an empirical framework that incorporates endogenous productivity change to evaluate and decompose the productivity effects of patents. This estimation approach directly considers the dynamic impact of patents and R&D on productivity, which avoids the potential bias caused by assuming an exogenous productivity process. To further investigate the mechanism through which patents affect productivity, I decompose the patent’s productivity effects into monopoly and scale effects. The estimation framework can be widely applied in evaluating and examining the driving factors of revenue productivity. Using a matched data set of the Chinese pharmaceutical industry between 2001 and 2007, I examine the impact of patents on productivity and the underlying mechanisms. The empirical results show that: First,only the lagged invention patents have a significant impact on the revenue productivity;second, the impact of patents on revenue productivity is working mainly through scale effects caused by the enhancement of physical productivity. Lastly, in the extension of the analysis, I show that patent subsidy has no impact on the productivity effects of patents;patent examination has effectively selected the high-quality products, and patents generated by private firms promote productivity more significantly than non-private firms.