城市网络联系对城市群空间体系集聚水平的影响——基于2003—2018年中国12个城市群面板数据的实证

本文分析了2003—2018年中国12个规模较大的城市群的空间体系特征及其变动趋势,并借助城际投资联系数据,分析了各城市群城市网络特征,实证检验了城市网络联系度对城市群空间体系集聚水平的影响。研究发现,2003—2018年城市群空间体系总体呈均衡化发展趋势,且不同城市群城市网络特征差异明显,按发育程度可以分为四种类型：联系紧密-结构均衡-强中心带动型城市网络,联系紧密-弱中心带动-相对开放型城市网络,结构均衡但联系相对较弱型城市网络,以及联系相对较弱且结构极化型城市网络。实证结果证实了城市网络联系的紧密程度和连通度的提高有利于降低城市群空间体系的极化水平,城市网络联系带来的外部性有助于避免城市群空间体系的过度极化及由此带来的集聚负外部性,实现更加均衡的城市群空间结构。但城市网络联系对城市群空间体系均衡化发展的作用依赖于城市网络的结构特征,城市网络结构的极化对城市群空间体系均衡化发展存在抑制作用。

Impacts of urban network connections on spatial concentration in urban agglomerations of China: An empirical analysis of 12 urban agglomeration regions from 2003 to 2018

The spatial structure of urban systems is not only determined by the agglomeration economy of each city, but also by the externalities generated from the integration and synergy of all cities within the region. Cities in the urban agglomeration region should not be considered as isolated entities, but interdependent and well-connected nodes within a network. It is argued that the urban network externalities can help avoid the over concentration of the urban system in the urban agglomeration region, and it is more likely to develop a balanced spatial structure when cities are more closely connected within the urban agglomeration region. This paper empirically tests the influence of urban network connections on the concentration of urban systems in major Chinese urban agglomeration regions. It analyzes the spatial structure and network characteristics of urban systems in twelve urban agglomeration regions of China by using the LandScan global population distribution data and the inter-city investment flow data compiled from the Chinese enterprise registration database. It is found that the urban agglomeration regions in China generally show the tendency of deconcentration of the spatial structure in their urban systems from 2003 to 2018. There is a large variation in the characteristics of urban networks among those urban agglomeration regions, which can be classified into four categories: well-connected, structurally-balanced and strong center-driven urban networks; well-connected, weak center-driven and relatively open urban networks; structurally-balanced but relatively less-connected urban networks; and less-connected and structurally-polarized urban networks. The empirical results confirm that the reinforcement of the closeness and connectivity of urban networks within the urban agglomeration region helps to reduce the polarity and concentration of urban systems, and urban network externalities help to avoid the excessive polarization of the urban system, which facilitates a more balanced spatial development of the urban agglomeration region. However, the effect of urban network connections on the balanced development of urban systems in the urban agglomeration region depends on the structure of urban networks, and the polarization of urban network structure leads to the concentration of urban systems in the urban agglomeration region. Therefore, the policy implication is that urban connections need to be strengthened to achieve the balanced and coordinated development of urban agglomeration regions, by providing cross-regional transport infrastructures and eliminating all kinds of institutional obstacles that hinder the free movement of production factors across regions, etc.