本文基于修改的内生增长模型,阐述了知识产权保护与OFDI逆向技术溢出的非线性关系。首先选取2003—2018年我国30个省份的面板数据,并借助三阶段SBM-DEA方法测算了绿色创新效率;在检验到绿色创新效率的空间自相关性以及知识产权保护的门槛效应后,构建了动态空间面板模型,实证研究了OFDI逆向技术溢出对绿色创新效率影响的门槛效应。回归结果表明,当知识产权保护处在较低水平时,OFDI逆向技术溢出对绿色创新效率的影响为负;只有当知识产权保护水平跨过门槛值后,OFDI逆向技术溢出对绿色创新效率的促进作用才明显。在异质性分析中发现,随着知识产权保护水平的提高,OFDI逆向技术溢出对绿色创新效率影响的单一门槛效应在国别、行业、地区数据分析中也得到验证。

Based on the modified endogenous growth model, this paper illustrates the nonlinear relationship between intellectual property protection and outward foreign direct investment (OFDI) reverse technology spillovers. The provincial panel data of 30 provinces in China from 2003 to 2018 are selected. A three-stage super-efficiency SBM-DEA model is used to measure the green innovation efficiency. After testing the spatial correlation of green innovation efficiency and the threshold effect of intellectual property protection, a dynamic spatial Durbin model is established. The paper empirically studies the threshold effect of OFDI reverse technology spillover on the green innovation efficiency. The results show that when intellectual property protection is at a low level, OFDI reverse technology spillover has a negative impact on the efficiency of green innovation; only when the level of intellectual property protection crosses the threshold, OFDI reverse technology spillover has a significant role in promoting green innovation efficiency. In the heterogeneity analysis, it is found that with the improvement of intellectual property protection level, the single threshold effect of OFDI reverse technology spillovers on the efficiency of green innovation is also verified by the data analysis of different countries, industries and regions.