An Empirical Study Of Polycentric Spatial Structure Evolution And Formation Mechanism

Urban spatial structure has always been one of the most classical topics among regional economics and urban geography, which has attracted amounts of exploratory researches. In recent years, many academic literatures have emerged focusing on the dispersion and the evolution of polycentric urban spatial structure from monocentric structure. Meanwhile, polycentric spatial strategy has also been applied to urban construction and planning in domestic mega-cities, moreover, these cities are trying to foster employment subcenters in periphery areas in order to decrease the diseconomy in central areas and optimize spatial distribution of production factors. However, it remains vague that whether these subjective goals could be better supplement of objective evolution of employment and population inside mega-cities. In one hand, much more scientific method should be advocated and integrated to assess whether mega-cities are becoming polycentric or not, in the other hand, complex elements inside mega-cities, such as institutional factors and government intervention, may determine the complexity of the evolution mechanism of urban spatial structure, therefore domestic studies concerning about the formation mechanism of employment subcenters and the determinants in this process remain vague and fuzzy.Based on the results of previous studies, this essay has used Shanghai metropolitan as an example to analyze the employment and population spatial evolution characteristics and mechanism. We have applied both qualitative and quantitative methods in order to emphatically illustrate our conclusion, including basic descriptive statistical analysis, nonparametric lowess regression, logistic regression, curve fitting and so on.This essay has concluded that there is a continuous and evident dispersion in both population and employment distribution since 1990s, and our study has identified the significant concentrated subcenters in peripheral areas, which strengthened the polycentricity of metropolitan area. Besides, we have concluded that the former agglomeration of labor force and transportation infrastructure have evident impact on the development of employment subcenters in Shanghai, which means agglomeration economy still matters a lot in terms of the formation of employment subcenters. Meanwhile, highly-educated rate and proximity to highway help to promote employment subcenters in Shanghai. Spatial determinants and economic structure also play a big role in the emergence of subcenters, employment subcenters tend to locate away from the central area, at the same time, both manufacturing and service can raise the probability of the emergence of employment subcenters. The construction of state-level development zone has some positive impacts on the formation of subcenters, but not quite significantly. Therefore, it is suggested that local government policies should be optimized in the future, at the same time, strengthening the coherence of policies is necessary.Also, there is no significant evidence that suburbanization could help promote polycentric employment distribution, and job-residential location is always unbalanced. While, it is still necessary for megacities to restrict the growth boundaries in central districts, in order to prevent inefficient spatial extension. At the same time, it is worthwhile to reinforce the agglomeration enonomies of subcenters in peripheral areas to relieve the crowded effect in central areas.