流空间视角下数字经济赋能城市群空间体系均衡化发展研究

在数字经济时代，数据要素与数字技术的广泛应用与推广破除物理时空壁垒，促进城际分工协作，深刻重塑以城市群为代表的区域经济地理格局，加速城市群空间体系由传统规模等级秩序向新时期均衡化发展模式演变。同时，城市群内多重要素流的交互联系推动形成网络化空间结构，有效提升整体网络外部性，进一步强化城市群数字经济发展水平对其空间体系均衡化程度提升的赋能表现。因此，数字经济赋能城市群空间体系均衡化发展的内在机制既存在直接效应，也存在流空间视角下城市群各类联系流网络的调节效应，包括交通信息网络、传统要素网络和创新要素网络。在理论框架指导下，文章以我国19个城市群为样本，建立多源数据库，测算各城市群的数字经济发展指数、空间体系均衡化程度以及基于三种联系流的网络外部性，总结特征事实，开展实证检验。基于特征事实的分析表明：我国19个城市群的数字经济水平稳步提升但存在较大的区域发展差距，形成相对梯度发展格局；大部分城市群空间体系均衡化程度提升，个别城市群呈现极化发展态势；各城市群均形成一定的网络型空间结构，但存在较大的个体异质性与区域异质性差距。基于实证检验的分析表明：城市群数字经济发展直接提升其空间体系的均衡化程度，工具变量回归和核心解释变量替换后的结果保持稳健；现阶段城市群内物的流动相比于人的流动更有利于经济活动空间布局的均衡化，第三产业主导的区域产业结构则在一定程度上加速城市群空间极化发展；城市群内交通信息网络、传统要素网络、创新要素网络的形成与发展具有正向调节作用，即进一步强化数字经济提升城市群空间体系均衡化程度的赋能表现；我国东、中、西部地区城市群的直接效应回归结果基本一致，但调节效应存在较大的区域异质性。文章首次建立数字经济促进城市群空间体系均衡化发展的理论机制框架，并通过特征事实阐释、实证检验分析等方法加以论证，为深入理解数字经济时代城市群空间体系的变革方向与优化路径提供参考与借鉴，对促进我国城市群高质量发展具有一定启示，即充分利用数字经济发展特性重塑城市群经济地理格局，加速形成多中心、网络化、均衡化的城市群空间体系，为提升我国新型城镇化建设整体协同性提供重要支撑。

Research on how digital economy empowers the balanced development of spatial system in urban clusters under space of flows perspective

In the era of digital economy, the widespread application and promotion of data elements and digital technology breaks the physical barriers of time and space, promotes inter-city division of labor and collaboration, profoundly reshapes the regional economic and geographical pattern represented by urban agglomerations, and accelerates the evolution of the spatial system of urban agglomerations from the traditional scale and hierarchy order to the new era of balanced development mode. At the same time, the interactive connection of multiple factors flows within urban agglomerations promotes the formation of networked spatial structure, effectively improves the overall network externality, and further strengthens the enabling performance of the digital economic development level of urban agglomerations in improving the spatial system balance. Therefore, the internal mechanism of digital economy enabling the balanced development of urban agglomerations'' spatial system has both direct effects and the moderating effects of various flow networks in urban agglomerations from the perspective of flow space, including traffic information network, traditional factor network and innovation factor network. Under the guidance of the theoretical framework, this paper takes 19 urban agglomerations in China as samples, establishes a multi-source database, measures the digital economic development index, the degree of spatial system balance and the network externality based on three kinds of flows, summarizes the characteristic facts, and carries out empirical tests. The analysis based on the characteristic facts shows that the digital economy level of 19 urban agglomerations in China has been steadily improved, but there is a large regional development gap, forming a relative gradient development pattern. The spatial system of most urban agglomerations is more balanced, while a few urban agglomerations show a trend of polarization. Each urban agglomeration has formed a certain network-type spatial structure, but there exists heterogeneity between individuals and regions. The analysis based on empirical tests shows that the digital economy of urban agglomerations directly improves the degree of spatial system balance, and the results remain robust after the regression of instrumental variables and the replacement of core explanatory variables. At the present stage, the flow of goods is more conducive to the spatial distribution of economic activities than the flow of people, and the regional industrial structure dominated by the tertiary industry accelerates the spatial polarization of urban agglomerations to a certain extent. The formation and development of transportation information network, traditional factor network and innovation factor network in urban agglomerations have a positive moderating effect, that is, to further strengthen the empowerment performance of digital economy to improve the degree of spatial system balance in urban agglomerations. The regression results of the direct effect of urban agglomerations in the eastern, central and western regions of China are basically consistent, but there is a large regional heterogeneity in the moderating effect. This paper firstly establishes the theoretical mechanism framework of digital economy promoting the balanced development of urban agglomeration spatial system, and demonstrates it through the methods of characteristic fact interpretation and empirical test analysis, which provides reference and reference for in-depth understanding of the reform direction and optimization path of urban agglomeration spatial system in the digital economy era, and has certain enlightenment for promoting the high-quality development of urban agglomeration in China.