基于城际创业投资联系的中国城市网络结构和组织模式

The spatial structures and organization patterns of China’s city network based on inter-city startup investments

鉴于现有的城市网络研究尚没有关注企业间投资这一最重要的经济行为之一,所得认知不全面,本文基于城际创业投资联系这一全新视角,刻画了中国城市网络的结构和组织模式,以丰富城市等级和距离衰减作用下的城市网络研究。从节点看,城际创业投资空间分布不均,高度集中在超大城市和直辖市。从联系看,城际创业投资具有明显的层级性,形成以京沪深为顶点的三角形框架,同时城际投资联系的距离衰减特征不充分,高等级城市不受距离约束,尤其是以京沪深为核心的三大城市群间的远距离联系,在1200 km左右形成投资"热岛"。从子网络看,城际创业投资可分成7个社区,社区分布具有"大集聚、小分散"特征,不同社区内部的组织模式各异,主要包括"单中心"模式、"一核多副"模式、"两核多副"模式和"多中心"模式。本文的创新点不仅在于填补了企业间投资网络研究的空白,还与企业总部分支网络进行了比较,结果发现城际创业投资的距离衰减特征强于企业总部分支网络,而等级联系特征则弱于企业总部分支网络。

The multi-level perspective city network is of great significance in understanding spatial interaction and linkages. Based on inter-city startup investments data, this study offers a new perspective to identify the spatial structure of China’s city networks from node-to linkagelevel, and further explore the organization patterns from sub-network-level. This study can deepen the understanding of city network structure under the effects of city hierarchy and distance decay. The results are shown as follows. At the node-level, the distribution of startup investments is uneven and highly concentrated in megacities and municipalities. Moreover, the rank-size distribution of startup investments tends to be more monocentric than that of population and GDP. At the linkage-level, first, the city network based on startup investments has an obvious hierarchical structure, and the connections between Beijing, Shanghai and Shenzhen are the strongest and form a triangular framework. Second, inter-city startup investments are mainly flowing within the same industry, and the service industry owns the most outflows and inflows. Third, inter-city startup investments display distance decay, but high-hierarchy cities can break the distance constraint. For example, the linkages are close between the three urban agglomerations with Beijing, Shanghai and Shenzhen as the cores. At the sub-network-level, seven communities are identified through community analysis, and we suggest that the community boundaries have two spatial characteristics including administrative district economy and the spillovers from high-hierarchy cities. Additionally, the organization patterns of communities are various, including single-core;single-core and multi-pairs;doublecore and multi-pairs;and multi-core patterns. Compared with the existing research for other perspectives of city network, there are two new findings in our study.