Polycentric Urban Spatial Structure And Its Economic Performance

Urban spatial transformation,fueled by the expansion of population size,has become one of the most important urban government issues all over the world.Urban planners have been seeking spatial adjustment strategies to meet the challenges caused by the agglomeration diseconomies associated with such expansion and often advocate for polycentric spatial structure.However,polycentric planning practices have long been controversial because they tend to fall short of achieving the desired results.The apparent shortcomings of polycentricity raise questions about the necessity and feasibility of pursuing it as a strategy: does polycentricity have better economic performance than monocentricity,that is,more economic benefits or fewer costs? And whether the influence of urban spatial structure on economic performance depends on population size? Compared with rich researches on the cost-benefit analysis of agglomeration scale,the influence of agglomeration structure has not achieved sufficient attention.Thus,academic evidence to support precise answers to the fundamental questions from practice remains inconclusive.Urban spatial structure can be defined mainly by two dimensions: centralized versus decentralized and clustered versus dispersed,thus polycentricity is deemed as a process of re-clustering after decentralization in our paper.This paper uses the Chinese Economic Census Data(2004,2008,and 2013)and describes the general information of Chinese cities’ spatial structure at the city proper scale.The main focus of this paper is to compare the positive and negative externalities of spatial structure from the perspective of economic benefits and costs,especially testing the heterogeneity of performance in different population size.The main findings are as follows:Firstly,results show that whether polycentricity contributes to economic benefits depends on city population size.Specifically,polycentricity is helpful to improve the economic benefits of larger cities,while monocentricity is more economically beneficial to small cities.Secondly,as one dimension of polycentricity,clustering spatial structure in small cities can help to save government expenditures.However,the negative externalities grow rapidly as the expanding of population size which driving up the government financial burdens.In particular,the investments in road and garbage treatments are obviously higher in clustering urban spatial structure in larger cities.Thirdly,the individual expenditures of small cities with monocentricity spatial structure are lower;polycentricity structure in large cities helps to reduce expenditures on transportation,medical treatment,and housing,thus providing an alternative choice to save costs of individuals in large cities.Fourthly,from the surplus of economic benefits and costs,small cities could have better economic performance if they are monocentric.On the contrary,polycentricity can help large cities earn more economic benefits and save more individual costs,while at the cost of high government expenditures.The potential contributions of this paper are as follows: on the analysis framework,this paper constructs a research framework of economic benefit-cost analysis and considers both positive and negative impacts of polycentricity by overall equilibrium,distinguishing this work from previous studies which only focused on economic benefits.On the definition and measurement of polycentricity,this paper deems the polycentricity as a process of re-clustering after decentralization.This analysis expands the understanding of impact paths of polycentricity’s economic performance by unfolding each of its dimensions more fully.Further,this paper focuses on the conditional effects of population size on the economic performance of the urban spatial structure.This paper has important policy implications for practice.The polycentricity strategies provide new energy for urban growth and are effective tools for dealing with the limitations of urban expansion.However,ignoring the stage of urban development and carrying out spatial strategies blindly face high risks.Monocentricity is more reasonable and even desirable in small cities.In large cities,polycentricity facilitates more economic benefits and less individual costs,but meanwhile high local government costs.