Abstract: China's economy has been thriving for decades since the adoption of the reform and opening-up policy. However, the long-term extensive mode of economic growth has given rise to various ecological challenges such as high energy consumption and high pollution. Industry is the main source of resource consumption and environmental pollution, and the coordination of industry development and preservation of environment is crucial to China's ecological civilization construction. Meanwhile, powered by a new generation of digital technology, the digital economy has experienced tremendous growth. China has prioritized the development and application of the digital economy, and China's digital transformation is rapidly advancing. The digital economy is expected to become a new engine to drive China's economic and social development. Therefore, if we can seize the new opportunities brought about by the digital economy, expand the new application of the digital economy, and further stimulate the potential of the digital economy to promote the industrial ecological efficiency, the increasingly severe ecological pressure in China will be alleviated. Motivated by the simultaneous rise of China's digital economy and the numerous ecological challenges it confronts, this paper aims to scrutinize the prospective positive and negative impacts that digital economy development may have on the industrial ecological efficiency. Additionally, it analyzes the intermediate mechanism in the impact of the digital economy on the industrial ecological efficiency from the perspective of technological innovation. Finally, it empirically examines how the development of the digital economy affects the industrial ecological efficiency and the intermediate mechanism of technological innovation. Based on the theoretical analysis, this paper uses the entropy method and the super-efficiency SBM method to measure the development of the digital economy and the industrial ecological efficiency respectively, and conducts an empirical research using a two-way fixed effect model based on the panel data of 41 cities in the Yangtze River Delta urban agglomeration from 2012 to 2019. The key findings of the study are as follows. Firstly, it is found that there is a U-shaped nonlinear effect of the digital economy on the industrial ecological efficiency. With the development of the digital economy, the industrial ecological efficiency shows a trend of decreasing first and then increasing. Secondly, the digital economy has both direct and indirect impacts on the industrial ecological efficiency. The digital economy affects the industrial ecological efficiency directly, while the independent innovation plays an intermediate role. The indirect impact of the technological innovation exhibits nonlinear characteristics. Specifically, poor development of the digital economy results in reduced independent innovation and industrial ecological efficiency. However, once the digital economy reaches a certain level of development, it promotes the independent innovation and boosts the industrial ecological efficiency. Thirdly, the impact of the digital economy on the industrial ecological efficiency is heterogeneous across urban scales and fiscal support levels. Concerning the urban scale, this paper finds that the development of the digital economy in small cities significantly reduces the industrial ecological efficiency. The impact of the digital economy on the industrial ecological efficiency in medium-sized cities is not significant, while in large cities, it significantly promotes its improvement. In terms of the fiscal support, we observe that the digital economy has no significant impact on the industrial ecological efficiency in cities with low fiscal support. In cities with moderate fiscal support levels, there is an inverted U-shaped relationship between the digital economy development and the industrial ecological efficiency. In cities with high fiscal support, we observe a U-shaped relationship between the digital economy development and the industrial ecological efficiency. The findings of this research have profound policy implications. Firstly, the government should continuously improve the quality and development level of the digital economy to stimulate its potential for improving the industrial ecological efficiency. Local governments should speed up the construction of the digital infrastructure while continuously upgrading the existing digital technology and infrastructure, so as to break through the turning point of the U-shaped relationship between the digital economy and the industrial ecological efficiency and the independent innovation. Secondly, the promotion effect of the independent technological innovation on the industrial ecological efficiency deserves more attention. A better environment for innovation needs to be created to fully release the social innovation vitality. Thirdly, governments should formulate specific policies based on regional industrial basis and resource endowment characteristics. Specifically, small and medium-sized cities should enhance the infrastructure construction and receive better policy support, while improving the quality of public service to enhance city attractiveness. The government should further improve the factor flow mechanism and optimize the industrial layout to promote the regional division of labor and cooperation. Finally, local governments should adhere to sustainable development principles and strike a balance between the industrial development and the ecological preservation. Governments should also adjust the structure of the fiscal expenditure, optimizing the fiscal expenditure efficiency.

Key words: Digital Economy, Industrial Ecological Efficiency, Technological Innovation, Regional Heterogeneity

摘要： 本文在分析数字经济对工业生态效率影响机理的基础上,利用2012—2019年长三角城市群41个城市的面板数据,实证考察数字经济对工业生态效率的作用特征及内在机制。研究结果发现,数字经济与工业生态效率之间存在U型关系,数字经济可通过自主创新间接影响工业生态效率,数字经济对工业生态效率的影响在不同区域有所差异。这一结论为深入理解数字经济对工业绿色转型的作用提供了新的证据。

关键词: 数字经济, 工业生态效率, 技术创新, 区域异质性