Abstract:

With the significant increase of social and economic interactions among constituent cities, city clusters have become the most striking geographic phenomenon in the twenty-first century. In the latest regional development strategy, city clusters have been positioned as the main spatial carriers of socioeconomic activities by the Chinese government. Although an increasing number of scholars has described the characteristics and proposed definitions of city clusters, there have been surprisingly few studies on the morphological change and influencing factors of city clusters' spatial structure based on population data. In most existing empirical studies on city cluster, instead of permanent resident population, registered household (hukou) population was used to measure city clusters' spatial structure and this introduces error. Hence, in this study we used two different sources of data-permanent resident population from the Chinese Census, and population of urban agglomerations released by the United Nations population division. Our sample is comprised of 13 city clusters.. Rank-size rule was applied to measure the morphological characteristics. The principal objective of this study is to examine the change and influencing factors of the spatial structure of Chinese city clusters. Our descriptive statistics show that there was a clear tendency towards polycentricity of city clusters during 1990-2010. Using two panel data analysis techniques (FE and FGLS) and different databases, we found that all else being equal, the spatial polycentricity of the city clusters is mainly associated with the increases of GDP per capita and population size. Most city clusters are in the stage of polycentricity, and only a few remain in the earlier monocentric stage. These findings have important policy implications for the development of urban clusters. For most city clusters with a polycentric tendency, the governments should promote integration within city clusters through transportation and regional coordination policies that strengthen the exchange of production factors and improve economic performance. For the few city clusters of monocentricity, however, the governments should avoid introducing polycentricity oriented policies too soon, which could be harmful to their economic performance. Due to methodological and data limitations, the endogenous problem between spatial structure and economic development is difficult to solve. The spatial structure of city clusters can be regarded as both a cause and a consequence of economic development. Hence, this two-way relationship might be correlative rather than causal. Further work should push forward in this regard to identify the real cause-effect. In addition, an increasing literature uses economic and transportation data to analyze city clusters from the perspective of functional linkage. This represents another direction that future research should focus on.

Key words: city clusters, spatial structure, change, influencing factors, monocentricity, polycentricity, China