Abstract: Improving the export commodity quality is a very important way to enhance the competitiveness of our industry in the international market, change the development mode of the foreign trade and build a new development paradigm. Enterprises are the main micro bodies of export and innovation. At the same time, contract enforcement institutions are the important securities to promote trade, stimulate investment and encourage innovation. Therefore, it is necessary to explore the importance of the contract enforcement institutions in enterprises' scientific and technological innovation and improving the export commodity quality. This paper provides a new analysis perspective and solution path to improve the export commodity quality and realize the high-quality development of the foreign trade.
From the perspective of enterprise innovation, this paper analyzes the mechanism of contract enforcement institutions influencing the improvement of the export commodity quality, and tests the results by the panel data of industrial enterprises in 29 provinces from 1998 to 2013 empirically. The results show that perfect contract enforcement institutions can not only directly improve the export commodity quality, but also make up for the defects of the human capital under-investment caused by the incomplete labor contract, stimulate the human capital investment, especially the high-level human capital investment, improve enterprises' technology innovation performance and the export commodity quality, thus producing the “human capital investment effect”. Perfect contract enforcement institutions can reduce R&D uncertainty of enterprises, increase the specific-relationship investment, encourage enterprises to choose more advanced technologies, improve the productivity and the export commodity quality, thus generating the “advanced technology selection effect”. Perfect contract enforcement institutions can reduce the risk of infringement of R&D achievements, protect the innovation income to some extent, encourage enterprises to continue to do R&D, and improve the quality of a country's export commodities as a whole, thus producing the “innovation rights protection effect”.
The fixed effect model and the mediation effect model are used to verify the above theoretical conclusions. Contract enforcement institutions not only directly promote the improvement of the export commodity quality, but also indirectly improve the export commodity quality through enterprises' innovation. The higher the quality of contract enforcement institutions, the higher the quality of export commodities. Considering the control variables, the indirect effect of contract enforcement institutions on the export commodity quality improvement through enterprises' innovation accounts for 12.5% of the total effect. By industry category, the higher the quality of contract enforcement institutions in provinces, the better the quality of enterprises' export commodities in the industries with the higher contract intensity. In terms of enterprises' nature, the contract enforcement institutions have the greatest effect on private enterprises' innovation and export commodity quality improvement, the least effect on that of state-owned enterprises, and the middle effect on that of foreign-funded enterprises. In order to reduce the possible measurement errors of the core explanatory variable due to different measurement methods, this paper uses the contract enforcement data of Doing Business in China 2008 for cross-sectional analysis. In order to solve the problem of missing variables better, this paper takes one lag period of the export commodity quality as an explanatory variable and constructs a dynamic panel data model for systematic GMM estimation. All the results pass the robustness test.
In the future, China needs to further improve the system and mechanism of the scientific and technological innovation, create a more relazed, more standardized, and more competitive institutional environment for enterprises' R&D activities, stimulate the innovation vitality of enterprises, improve the institutions of laws and regulations related to contracts, improve the efficiency of resolving contract disputes, and protect the intellectual property rights. Governments at all levels, especially in the central and western regions, still need to make great efforts to strengthen institutional innovation to provide inexhaustible impetus for enterprises' innovation, narrow the regional development gap and ensure high-quality economic development. As the dependence on contract enforcement institutions varies from industry to industry, in the market competition environment of “Quality is the King”, it is more necessary for the government to formulate strategic trade policies scientifically, give better play to the external economic effect of innovation and ultimately improve the export commodity quality on the whole on the premise of guaranteeing the innovation rights of enterprises.

Key words: Contract Enforcement Institutions, Export Commodity Quality, Enterprise Innovation, Mediation Effect Model

摘要： 本文基于企业创新视角,分析契约执行制度对出口产品质量提升的影响机制和效应,运用我国29个省份1998—2013年工业企业面板数据进行实证检验。研究结果表明,完善的契约执行制度不仅直接促进出口产品质量提升,还通过“人力资本投资效应”“先进技术选择效应”“创新权益保障效应”三条路径提高出口产品质量。理论层面的影响机制较好地通过固定效应计量检验,分产业类别和企业所有制类别的实证结果也支持以上结论。在使用《2008中国营商环境报告》中强制执行合同指标数据进行截面分析和系统GMM法估计后,结果依然显著。因此,未来我国需在完善科技创新体制机制、提高契约执行制度质量、激励企业创新投资和保障创新企业利益等方面做更多工作,进而从整体上提高出口产品质量。

关键词: 契约执行制度, 出口产品质量, 企业创新, 中介效应模型