统计与数据科学学院知识库

数字经济与绿色技术创新是国家近年来重点关注的领域。伴随我国绿色低碳循环发展经济体系的建立，绿色技术创新逐渐成为打好污染防治攻坚战、推动绿色发展的重要动力。数字经济具有鲜明的数字化、网络化、智能化等特征，逐渐成为促进我国绿色技术创新的新引擎。而长江经济带作为国家生态优先绿色发展的主战场，其生态环境污染问题十分突出，对绿色技术创新的需要更为迫切。因此，研究长江经济带数字经济发展能否提升绿色技术创新水平，对于长江经济带乃至全国的绿色发展具有重要的理论及现实意义。  

  本文对长江经济带2011—2021年的108个地级市的面板数据展开分析。首先，通过熵值法测度得到长江经济带各城市数字经济发展水平，了解其整体及不同区域的数字经济发展情况。其次，基于测度结果，对各变量进行描述性统计分析；通过固定效应模型和分位数回归模型分析数字经济对绿色技术创新的直接影响，并从不同方面探讨了长江经济带数字经济对城市绿色技术创新的异质性。最后，通过中介效应模型和调节效应模型分析数字经济影响绿色技术创新的间接效应。文章旨在通过以上分析发现二者在发展过程中可能存在的问题，对促进长江经济带绿色技术创新以及实现区域协调绿色发展提出针对性建议。

  主要结论如下：第一，数字经济发展水平和绿色技术创新水平的测度结果表明长江经济带区域内部的发展存在显著差异。整体来看，数字经济发展水平呈现不断上升的趋势，2011—2021年数字经济发展水平均值从下游、上游到中游依次下降。长江经济带绿色技术创新水平在2020年之前总体呈上升趋势，在2020年之后有所下降。2011—2021年绿色技术创新水平均值最高的是下游地区，其次是中游地区，上游地区最低。第二，数字经济发展能够有效提升长江经济带城市的绿色技术创新水平，该结论在经过替换被解释变量、剔除特殊城市、缩尾处理、内生性检验等一系列稳健性检验后依然成立。第三，数字经济可以在一定程度上以推动金融发展、加快产业结构升级的方式来促进绿色技术创新。其中，金融发展水平和产业结构升级的中介效应分别为18.80%和15.38%。另外，政府支持能够强化长江经济带数字经济发展对绿色技术创新的促进作用。第四，数字经济对绿色技术创新水平的影响在不同绿色技术创新水平、不同区域、不同城市等级、不同人口密度的情况下均存在差异。具体来看，数字经济发展在不同绿色技术创新水平下均能显著促进绿色技术创新。数字经济发展能够显著促进核心城市群地区、下游地区的绿色技术创新水平提升，而对非核心城市群地区、上中游地区的影响并不显著。数字经济发展对不同城市等级和不同人口密度的城市绿色技术创新均具有显著促进作用，且对中心城市和高人口密度城市的绿色技术创新具有更强的驱动作用。

  基于以上结论，文章从实施区域差异化数字经济政策，加快实现长江经济带区域协调绿色发展；多主体参与及多举措并行，共同为绿色技术创新提供资金保障；优化生产要素配置，加快产业转型升级；强化区域增长极、核心增长极的辐射作用，缓解长江经济带区域发展不平衡等四个方面提出建议。

Digital economy and green technology innovation have been the key areas of the country in recent years. Along with the establishment of China's green, low-carbon and recycling development economic system, green technological innovation has gradually become an important driving force for fighting the battle against pollution and promoting green development. Digital economy has distinct characteristics of digitalization, networking and intelligence, and has gradually become a new engine to promote green technology innovation in China. The Yangtze River Economic Belt, as the main battlefield of national ecological priority and green development, has prominent ecological and environmental pollution problems, and the need for green technology innovation is more urgent. Therefore, it is of great theoretical and practical significance to study whether the digital economy development can improve the level of green technology innovation for the green development of the Yangtze River Economic Belt and even the whole country.

This paper analyze the panel data of 108 prefecture-level cities in the Yangtze River Economic Belt from 2011 to 2021. Firstly, the digital economy level of each city in the Yangtze River Economic Belt is obtained by entropy measurement to understand its overall and different regions' digital economy development. Secondly, based on the measurement results, descriptive statistical analyses of the variables are carried out; the direct impact of digital economy on green technological innovation is analyzed through fixed effect model and quantile regression model, and the heterogeneity of the digital economy in the Yangtze River Economic Belt on the green technological innovation of the cities is explored from different aspects. Finally, the indirect effect of the digital economy affecting the green technological innovation is analyzed through mediating and moderating effect models. The article aims to find out the problems that may exist between the two in the process of development through the above analysis, and puts forward targeted suggestions for promoting green technological innovation in the Yangtze River Economic Belt as well as realizing coordinated green development in the region.

The main conclusions are as follows: First, the results of the development level of digital economy and green technology innovation show that there are significant differences in the development of the Yangtze River Economic Belt. On the whole, the development level of digital economy shows a rising trend. In 2011-2021, the average value of digital economy development drops from the downstream, upstream to the middle reaches. The level of green technology innovation in the Yangtze River Economic Belt showed an overall upward trend before 2020, and decreased after 2020. From 2011 to 2021, the downstream region with the average value of green technology innovation is the highest, followed by the middle region and the upstream region is the lowest. Second, the development of digital economy can effectively enhance the level of green technological innovation of cities in the Yangtze River Economic Belt, and this conclusion still holds after a series of robustness tests such as replacing the explanatory variables, excluding special cities, shrinking tails treatment, and endogeneity test. Third, the digital economy can, to a certain extent, promote green technology innovation by improving the level of financial development and promoting the upgrading of industrial structure. Among them, the intermediary effect of financial development level and industrial structure upgrading is 18.80% and 15.38%, respectively. In addition, government support can strengthen the role of digital economy development in the Yangtze River economic Belt in promoting green technology innovation. Fourth, the impact of the digital economy on the level of green technological innovation varies across different levels of green technological innovation, regions, city classes, and population densities. Specifically, the development of digital economy can significantly promote green technology innovation under different levels of green technology innovation. The development of digital economy can significantly promote the improvement of green technology innovation level in core urban agglomerations and downstream regions, while the impact on non-core urban agglomerations and upper and middle regions is not significant. The development of digital economy plays a significant role in promoting urban green technology innovation at different urban levels and with different population density, and has a stronger driving role in promoting green technology innovation in central cities and cities with high population density.

Based on the above conclusions, the paper proposes the implementation of regional differentiated digital economic policies to accelerate the coordinated green development of the Yangtze River Economic Belt, multi-subject participation and multiple measures to jointly provide financial guarantee for green technology innovation, optimize the allocation of production factors, accelerate the industrial transformation and upgrading, strengthen the radiation effect of regional growth pole and core growth pole, and alleviate the unbalanced regional development of the Yangtze River Economic Belt.