The Mystery Of "Subsidence" Of Medium-sized Cities In China

In the notification of the key tasks of the new urbanization construction in 2019,it was proposed to relax the requirements for household registration in large cities.For the first time,the concept of "shrinking city"was mentioned.The shrinking city is the city with population loss.Under the background of new situation and new policy,the following topics are worth discussing:how the layout of urban system in China is,which cities are shrinking,and what characteristics these cities show.Based on these,this paper chooses those cities with urban population scales of the Fourth,Fifth and Sixth Census as research objects,and explores the distribution status of the urban system in China through theoretical and empirical analysis.In theory,on the basis of reviewing the relevant literature on urban scale distribution,two common laws of urban scale distribution,Zipf s law and Gibrat's law,are sorted out and discussed in detail from the aspects of statistical distribution law and economic principle.Empirically,this paper studies the growth differences of more than 600 cities at county level and the characteristics of coordinated development of urban system in China from 1990 to 2010.Through parametric and non-parametric tests,the characteristics of urban size distribution in a specific period are analyzed.Besides,the dynamic change trend of urban population of different scales in the urban system is also analyzed by constructing Markov transformation matrix.The conclusions are as follows:Zipf s law test shows that the urban system in China has been improved from"flattening",which means small and medium-sized cities are dominant,to positive equilibrium;Gibrat's law test shows that China's urban system is characterized by non-logarithmic normal distribution,mainly due to the "collapse" of medium-sized cities,resulting in the imbalance of China's urban system;Markov transformation matrix complementarily shows the characteristics of relatively stagnant growth of medium-sized cities.Secondly,this paper further explores which cities have "collapse" phenomenon,the distribution and individual characteristics of collapsed cities,and emphatically analyses the causes of the collapse of medium-sized cities from the perspective of administrative division adjustment policy and industrial structure.The results show that the growth rate of urban population scale from 1990 to 2000 is significantly correlated with the adjustment of administrative divisions.Most of the medium-sized cities with"collapsed" scale have not experienced the adjustment of administrative divisions.From 2000 to 2010,the location quotient of manufacturing and productive services in medium-sized cities is lower than that in big cities,the export employment multiplier is smaller,the industrial correlation is weaker,and the population growth rate is relatively more stagnant.Finally,in view of the disharmony in China's urban system,the strategic focus of China's future urbanization is to promote the rise of a number of medium-sized cities and promote the balanced development of the urban system.