The Theoretical Construction And Method Study Of Population Spatial Equilibrium ——Take Yangtse River Delta As Example

Population equilibrium development is the value guidance and ideal pursuit of China's population policy,also has a significant meaning to regional equilibrium development.However,there still exists puzzles about the interpretation of population spatial equilibrium,and its scientific connotation needs more explanation and propaganda.The concept of population spatial equilibrium was rather unclear in China at present,it is difficult to ensure the definition of population spatial equilibrium,such as average distribution of population,rational distribution of population and population spatial optimization and other related concepts.The selection and quantification of key indicators of population spatial equilibrium are not mature enough,its scientific connotation also needs more explanation and publicity.Based on the concept and scientific connotation of population spatial equilibrium,this paper puts forward a theoretical model of multi-regional population spatial equilibrium based on regional wage rate,human climate suitability index,urban crowding degree and distance,takes the Yangtze River Delta as example to analyze the equilibrium population spatial distribution in current economic,social,environmental and population conditions.The specific content is as follows:Chapter 1 is an introduction,which summarizes the research status of population spatial equilibrium.The western research contains four main parts: The population spatial equilibrium of socio-economic structure derived from the market elements of macroeconomics,especially the free flow of labor force;the spatial equilibrium of population and other elements under the influence of the provisions of natural geographical space;the population equilibrium of residential area system in the process of urbanization,and the population spatial equilibrium derived from the sense of ecological equilibrium.Domestic research has made some explorations in the academic brewing of population spatial equilibrium and the connotation and extension of academic concept,the analysis of the main problems and causes of population spatial equilibrium development in China,the exploration of the definition and measurement method of population spatial equilibrium degree,the strategic planning and countermeasures of population equilibrium development,and obtained some valuable research results.However,there are differences between eastern and Western scholars in the research technical route.Due to the lack of government guidance,western scholars pay more attention to the bottom-up empirical research,especially the utility equilibrium between individuals and families,from micro to macro;Chinese scholars start from the government's planning concept and talk about the macro function from top to bottom,from macro to micro.Both sides have their own starting points and footholds,and integrate is of uppermost priority.For our Chinese scholars,we need to learn from western research,find the intersection and common ground,finally reach a common context and discourse system.Based on the understanding of equilibrium in different disciplines,chapter 2 makes a theoretical discussion on equilibrium,population equilibrium and population spatial equilibrium.The equilibrium in physics,economics,law and other disciplines mostly emphasizes the concepts of balance,stability or justice,and emphasizes the state of restoring from disequilibrium to equilibrium or generating new equilibrium,which is a process of systematic spontaneous regulation.This chapter puts forward equilibrium is a stable equilibrium state.The generalized sense of population equilibrium has two aspects: value meaning and mechanism significance,the academic circles have many research on value meaning of population equilibrium,this paper focuses on the latter.Population equilibrium in the sense of mechanism refers to a stable state.The population spatial equilibrium of mechanism significance gives the meaning of space on the basis of population equilibrium,which can be understood as the spatial equilibrium of population distribution.When other factors population remain unchanged,the net migration between regions is zero,that is,the total immigrants of each region is equal to its total emigrants,so as to achieve the dynamic equilibrium of population distribution among regions.Migration stream will be exist between regions in equilibrium state,migration and equilibrium can coexist,but the population distribution between regions remains dynamic and stable,and the population spatial distribution structure will not change.The inherent stipulation of population spatial equilibrium originates from specific conditions.With the change of economic,social,resource and environmental conditions,the position of equilibrium point will also change.From the instantaneous concept,equilibrium is only a relative concept;Instantaneous equilibrium is an ideal state in the long term,and the population spatial distribution is always in the process of changing from disequilibrium to equilibrium,and from equilibrium to disequilibrium.Chapter 3 establishes a general population spatial equilibrium theoretical model about population migration behavior based on push-pull theory.Population spatial equilibrium refers to that individuals(or families)migrate between different regions due to various economic or non-economic factors at any time,so each region will experience population immigration and emigration.When other factors remain unchanged,the net migration between regions is zero,that is,to achieve the dynamic equilibrium of population distribution among regions.In order to instantiate the population spatial equilibrium model,this chapter uses the Cobb-Douglas production function composed of capital,labor force and production technology level to describe the regional macroeconomic production,and uses the Wilson spatial interaction model to describe the inter regional population attraction composed of thrust and pull.Based on the existing research,this chapter establishes a population spatial equilibrium model including a series of equations such as production function,attraction function and population migration function based on regional wage rates,human climate suitability index,urban congestion and geographical distance.Its goal is to solve the distribution of workers in the equilibrium state,and solve the nonlinear equations through gams programming.Based on the relatively complete and independent physical geography,close internal eco-social ties and active market economy of the Yangtze River Delta,chapter4 takes the Yangtze River Delta,as the research area.This chapter analyzes the population growth trend of the Yangtze River Delta.Since the founding of the People's Republic of China,the total population of the Yangtze River Delta has increased steadily,but there are significant differences in population growth rate in each region.Taking the average annual growth rate between the two close census years as the index,this chapter finds that: firstly,the average annual population growth rate of the Yangtze River Delta as a whole and Jiangsu and Anhui provinces has experienced a process of increased earlier and decreased later and becoming stable at this stage.The early form of Zhejiang is basically similar to that of the Yangtze River Delta.After 2000,there has been an obvious tail warping phenomenon.Shanghai is the highest morphological difference,which is exactly reverse with the Yangtze River Delta.Secondly,the population density distribution takes Shanghai as the apex,Suzhou,Wuxi,Changzhou extends to Nanjing along the Shanghai-Nanjing Expressway and railway,and Jiaxing and Hangzhou extend to Ningbo as the skeleton.The population center of gravity is always in the southeast and has a trend of continuous migration to Shanghai,indicating that the population spatial distribution is concentrated in the southeast.With Shanghai,Southern Jiangsu,Northern Zhejiang and other regions rapidly becoming powerful population concentration centers,the population center of gravity is likely to continue to shift to the southeast in the future.Finally,this chapter uses Zipf's law to test and find that the linear form of rank-size rule is roughly the same of the seven censuses in 41 cities.This chapter think the change of grade scale distribution has been relatively small of 41 cities in the Yangtze River Delta,the overall structure tends to be stable between the seven censuses.Chapter 5 calculates the population spatial equilibrium distribution of the Yangtze River Delta,found that population distribution of the Yangtze River Delta in the equilibrium state is consistent with Zipf's law than the current real population distribution,which indicates that the equilibrium population distribution can illustrates the natural evolution results of the multi-regional population spatial structure;the population of Yangtze River Delta is concentrated along the river and along the coast,mainly including the south of Jiangsu,the coast of Hangzhou Bay,and the canal from Nanjing to north of Jiangsu;Comparing the equilibrium population with the existing scale,the Yangtze River Delta can be divided into quasi-equilibrium area,attractive area and repulsive area.The attractive areas such as Shanghai,Nanjing and Hangzhou,have strong population agglomeration potential;the repulsive areas are mainly distributed in Northern and Western Anhui,Northern Zhejiang and other areas,close to the population near quasi-equilibrium area,which indicates that under the condition of free migration,the population will further gather in Shanghai,Nanjing,Hangzhou and southern Jiangsu area.Chapter 6 reviews the change of population migration policy and the regional difference of hukou policies in the Yangtze River Delta.The regional central cities mainly located in Shanghai and Nanjing set strict threshold to curbed inflows of floating population,so as to alleviate the bearing capacity and management difficulties of the city.To compare the effects of different hukou policies on population spatial distribution in the Yangtze River Delta,this chapter set three different labor migration probability to tackle the difficult of quantifying hukou policies.Based on this,the population spatial equilibrium distribution of 41 cities under the hukou policies is recalculated.Comparing the three simulation results,this chapter found that the population equilibrium distribution of 41 cities in the Yangtze River Delta under scenario 1,that is,the scheme with high Probability of successful migration,is closer to the baseline scenario,and scenario 3,that is,the scheme with low probability of successful migration,has the most deviation from the benchmark scenario.However,the larger cities and smaller cities deviate significantly from the Zipf fitting line in three scenarios,that is,the population scale points of the cities with the top and bottom ranking fall below the fitting line,and the scatter points are the same as the real population distribution,appearing the shape of cooking smoke,especially compared with the fitting line,the tail scatter points have obvious dropping phenomenon.Chapter 7 summarizes the results of this paper and makes relative promotions,suggests some other problems that are worth further studying.