中国城市网络的凝聚子群及影响因素研究

凝聚子群特征及形成机理的研究是理解城市网络发育规律及其动力机制的重要切入点。利用2016年中国上市公司500强企业总部-分支机构数据,研究了中国城市网络凝聚子群的多维度特征,定量测度了城市间链接关系的影响因素,探索性的分析了凝聚子群的形成机理。结果发现：派系、k-核、lambda集合、核心-边缘方法都表明中国城市网络存在凝聚子群现象,揭示了城市网络链接强度的层级特征;经济规模、政治资源、知识资本是凝聚子群发育的重要影响因素,网络邻近性、地理区位和历史基础也深刻的影响着凝聚子群的空间格局;择优链接和路径依赖是凝聚子群发育的动力机制,城市关键资源和区位优势将进一步转化为城市网络竞争优势。在网络发展环境下,中国政府需要在更大空间尺度上推动城市间合作,并积极应对城市间发展差距趋于扩大的问题。

Cohesive subgroups and underlying factors in the urban network in China

Cohesive subgroup constitutes a bridge connecting individual cities and urban network. This paper aims to analyze the cohesive subgroups and their mechanisms in the urban network in China. First, data on headquarter and branch locations of China's top 500 public companies in 2016 are subjected to ownership linkage model to approximate the urban network, resulting in a 294×294 valued urban network. Second, four measures of cohesive subgroup analysis, i.e. cliques, k-cores, lambda sets and core-periphery techniques are employed to generalize about the link strengths between cities. Finally, the influencing factors of the cohesive subgroups in the urban network are examined by using quadratic assignment procedure, and the mechanisms are explored under a conceptual framework of urban network growth. Three main findings are concluded. First, the four measures of cliques, k-cores, lambda sets and core-periphery techniques all indicate the presence of cohesive subgroups, revealing the hierarchical structure of link strengths in the urban network in China. The cohesive subgroups are mainly composed of core cities of urban agglomerations, and the cities in the eastern and central regions have more active economic ties compared to the cities in the western region. Second, key resources possessed by cities, such as economic scale, political resources, and knowledge capital, are important factors underlying the formation of cohesive subgroups. Links are more likely to occur between cities with larger economies, richer political resources and more intensive knowledge capital. Temporal distance, geographical location and path dependence also have a profound influence on the spatial pattern of cohesive subgroups. Third, network homophily and path dependence are the dynamic mechanisms underlying the development of cohesive subgroups, and the key resources and location advantages of cities will be further translated into network competitiveness. In the network environment, China's urban governance system and urbanization policies need to be adjusted accordingly. The Chinese government needs to promote network cooperation between cities on a larger spatial scale, and actively respond to the widening economic gap between cities under the network environment.