基于双重差分模型的参与PPP项目与企业技术创新关系研究

以2011～2018年沪深主板市场上市的企业作为研究对象，分析了上市企业参与PPP项目建设对企业自身技术创新水平的影响，并进一步探讨行业竞争对二者关系的调节效应。研究发现企业参与PPP项目建设总体会抑制企业技术创新投入，并且参与PPP项目程度越深，抑制作用越明显。二者的关系在科技型行业和传统型行业中存在异质，参与PPP项目有助于提高科技型企业技术创新，但是不利于提高传统型企业技术创新。行业竞争对PPP项目与企业技术创新的关系产生显著的调节作用，随着行业竞争加强，参与PPP项目与科技型企业技术创新的正相关越大，参与PPP项目与传统型企业技术创新的负相关越小。对此，企业家要有长远意识，坚持创新型发展，同时监管部门要充分利用行业竞争机制加快产业转型升级，破除垄断关系。

Research on the Relationship between PPP Participation and Enterprise Technological Innovation Based on Double Difference Model

Taking the enterprises listed in main board of the stock market from 2011 to 2018 as the research object, this paper analyzes the impact of listed enterprises'participation in PPP project on their own technological innovation level and further explores the regulatory effect of industry competition on participating in PPP projects and technological innovation of enterprises. The results show that, enterprises' participation in PPP project will inhibit enterprises technology innovation investment, and the deeper participation in PPP projects, the more obvious inhibition effect. The relationship between them is heterogeneous in science and technology industry and traditional industry, the participation in PPP projects helps to improve technological innovation of technology-based enterprises, but it is not conducive to improving technological innovation of traditional enterprises. Industry competition has a significant regulatory effect on the relationship between PPP projects and technological innovation of enterprises. With the strengthening of industry competition, the greater the positive correlation between PPP project participation and technological innovation of technology-based enterprises, the smaller the negative correlation between PPP project participation and technological innovation of traditional enterprises. Therefore entrepreneurs should have a long-term awareness, adhere to innovative development, and at the same time, regulatory authorities should make full use of the market competition mechanism to accelerate the transformation and upgrading of industries, and break the monopoly relationship.