Different disciplines have different explanations for the phenomenon and process of urbanization: according to economics, urbanization is a process in which economic elements of various non-agricultural industries gather in cities and urbanization and non-agricultural industrial structures develop simultaneously; Demography believes that urbanization refers to the phenomenon and process of population urbanization, that is, the rural population gradually changes into the urban population. In the Dictionary of Demography edited by Christopher Wilson, the explanation is: "Population urbanization refers to the phenomenon that the proportion of people living in urban areas rises"; Geographically speaking, urbanization is the spatial location distribution and economic layout of residential settlements, and it presents an increasingly centralized process; Sociology believes that urbanization is a development process of urban lifestyle, which means that people are constantly attracted to the city and incorporated into the life organization of the city. To sum up, we can understand the definition of urbanization from four aspects: first, urbanization is the change of population distribution structure in rural and urban areas; The second is the transformation of urban industrial structure and its layout regional structure; Third, urbanization is the transformation from traditional values and lifestyles to modern values and lifestyles; Fourthly, urbanization is the change or innovation of people's life style, gathering mode and related institutional arrangements. But as far as the urban housing industry is concerned, to study the influence of urbanization on the housing industry, we must first start with the transformation of the rural population distribution structure, which is the result of urbanization.

From the perspective of "demography", the concept of urbanization is mostly defined as the process of rural population gathering in cities, or the process of urban population gradually increasing in the total population. However, the urbanization practice in developed countries and some big cities in China (such as Shanghai and Peking) shows that this definition is too narrow. In fact, the process of population urbanization is not only the process of population concentration, but also the process of population dispersion (so-called population suburbanization). Because population suburbanization itself is a dynamic process of population movement, there will be "outflow" and "inflow", and there will be "pull" and "thrust", so it is a coordinated process. To explore the reasons of population suburbanization, we must first find out the reasons of population flow. There have always been different opinions about the reasons for population mobility: Marx believes that the fundamental motivation of population mobility lies in social division of labor and socialization of production; Western scholars, such as Everett S.Lee, believe in his Migration Theory that there are four factors that determine population migration: the first is emigration, the second is emigration, the third is intermediate obstacle, and the fourth is the intervention factor of migrants; Kuznitz believes that population mobility is the result of changes in economic opportunities caused by technological progress; Schultz and others believe that population mobility is one of the five main aspects of human investment and an investment behavior, which is determined by cost and income; According to Todaro's expected income theory, the population flow in underdeveloped countries is determined by two main variables: one is the actual income gap between urban and rural areas, and the other is the employment probability in cities and towns, which determine the expected income of floating population in cities and towns. To sum up, the author believes that the fundamental reason of population mobility lies in the regional income gap caused by social and economic development and the yearning and pursuit of quality life.

It can be considered that the essence of the process of population urbanization is the process of regional life gap caused by social, economic and technological development, which leads to people's expectation of expected income and yearning for urban quality life. From the part of speech, population suburbanization should be the antonym of population urbanization, but practice has proved that "population suburbanization" is always a by-product of population urbanization, which is definitely not a literal simple understanding: the population has changed from urban residents to rural residents and become the mainstream of population mobility. Therefore, the author thinks that the true meaning of population suburbanization can be understood from two aspects: first, it is an auxiliary phenomenon of population redistribution in "population urbanization"; Second, it is a phased dynamic development process. The phenomenon of population suburbanization in this paper mainly refers to the flow of population from the original central city or suburb to the marginal area and suburb of the central city.

Second, the empirical analysis of population suburbanization

After studying the urbanization process in developed countries, some scholars divide the world urbanization development process into three stages and six periods: centralized urbanization, suburbanization and reverse urbanization (see table 1).

The research shows that when the urbanization rate of a country or region reaches 75%, the development speed of urbanization will enter a relatively stable and developed stage, which indicates that the developmental urbanization stage has been basically completed. At this time, urbanization will enter the stage of coexistence of concentration trend and diffusion trend, and the development period dominated by diffusion trend (core cities will enter the recession stage). Shanghai's urban development proves this situation from two aspects: first, the suburbanization of the population in the core city. Since 1980, the population of Luwan and Jing 'an District in the city center has still shown a slight growth trend during the period of 1980~ 1982, with an average annual growth of more than 1000 people. However, from 1982, it turned into a continuous decrease, with an average annual decrease of 5000 ~. 1982 is regarded by experts as a turning point in Shanghai's population distribution and urbanization development. By 2000, the population of Luwan and Jing 'an (see Table 2 for other districts) had decreased from 500,000 and 420,400 in 1993 to 328,900 and 305,400 respectively, a decrease of1715438+0.5. The population density of the two districts decreased from 64,900 and 66,900 per square kilometer in 1.982 to 46,700 and 50,000 in 1.997, and to 40,800 and 40,000 in 2000. It can be said that in recent years, the suburbanization phenomenon of the population in the central city of Shanghai, especially in the central city, is quite obvious, and the population in the core city mainly shifts to the marginal area of the central city; On a large scale, during the period of 1.993-2000, the population of the core urban areas (Huangpu, Luwan, Jing 'an and Hongkou) decreased from 25 1.4 million to 2,069,300, with an average annual decrease of 63,500. The fringe areas of the core city (Xuhui, Changning, Putuo, Zhabei and Yangpu) increased from 3,892,500 in1.93 to 4,860,830, with an average annual growth rate of1.383; Pudong New Area and Minhang, Jiading and Baoshan Districts in the suburbs increased from 3,073,600 to 5,600,700, an increase of 45 1%, with an average annual increase of 360,000; The number of people in suburban counties increased from 346 1.300 to 3,894,600, an increase of 1. 1.2%, with an average annual increase of 72,000 people.

For example, the general trend of population distribution in Shanghai is that the population in the core city keeps flowing out, the population keeps decreasing, and the population in the periphery and suburbs of the central city grows rapidly, inheriting the outflow population and the population entering the city in the core city. According to relevant statistics, since 1990, the scale of diffusion and migration from the core city of Shanghai to the periphery has reached an average of about 65438+ 10,000 people every year. The second is the spatial evolution of population migration and distribution in core urban areas. From the perspective of population migration and flow, the distribution center of people who moved in or flowed in also moved outward from the city center to the marginal areas. Take the registered migrants as an example. Since 1980s, on the one hand, the net mobility has a positive correlation with the distance from the city center (see Table 3). For example, the correlation coefficients between the net mobility and the distance from the city center of 1980, 1985 and 1990 are 0.844 and 0.84 respectively. At the same time, with the passage of time, the intensity of net emigration from the city center has been increasing, and the area of net emigration has gradually expanded. From the perspective of floating population, the same is true of distribution. Since the 1960s, the floating population in Shanghai has accounted for 12% ~ 20% and 60% respectively, and in the 1990s, the proportion has changed to 5% ~ 8% and 75% respectively. According to the fact that the population is mainly distributed in urban fringe streets and general streets, the proportion is above 60%; Moreover, this proportion has an obvious upward trend. 1Compared with the sixth survey of floating population in Shanghai in the 1980s, the floating population in the central urban area (core urban area and marginal area) 10 area is 1 1.4% of the local registered population. Baoshan, Minhang, Jiading, Pudong New Area and other new urban areas have an inflow population of 6.5438+0.22 million, accounting for 25. 1% of the local registered population, while other suburban counties have an inflow population of 440,000, accounting for 8.5% of the local registered population. The proportion of inflow population in new urban areas such as Baoshan is significantly higher than that in central urban areas and suburban counties. Moreover, the proportion flowing into suburban counties also decreases with the decrease of population in suburban counties. Thirdly, the influence of population suburbanization on the spatial distribution of urban housing industry.

Scholars at home and abroad generally believe that the development of housing industry can be divided into three stages: the initial stage. With the agglomeration of industries in cities, the number and population size of cities are gradually increasing. Because of the slow growth of urbanization and the low population base in cities and towns, there is little pressure on urban housing. On the other hand, the low level of economic development and the material basis of the city determine that most residents can only live in a harsh living environment. Accelerate the development stage. When the urbanization level of a country or region, that is, the proportion of urban population to the total population reaches 30%, industrialization and economic development have laid a certain foundation. Driven by its inertia, the level of urbanization has increased rapidly in a short time, the number and population of cities have increased sharply, and big cities have expanded suddenly. For the sudden population wave, the speed of urban housing construction lags far behind the growth rate of urban population, resulting in a tight housing situation. Late stage. Its main signs are: after the urbanization level exceeds 70%, the growth rate of urban population slows down, and the population in the central area of big cities spreads to the suburbs, resulting in the so-called "suburbanization" phenomenon. The leading role of industry in promoting urbanization has been replaced by the tertiary industry, and the whole region has formed an urban network with close integration and orderly development of large, medium and small cities. After long-term construction and accumulation, the cities in this period have rich material foundation, high economic level and housing. The author can get a chart of urbanization rate, residents' income and housing elements by synthesizing various data. At present, Shanghai's per capita GDP has reached 4000 US dollars, and the urbanization rate has reached and exceeded 70%. In other words, the consumption structure of Shanghai residents should be in the stage of pursuing individuality and fashion, the city should be service-oriented, and the proportion of residential consumption expenditure should be above 16%. However, the actual housing of Shanghai residents is still at the intersection of the second stage and the third stage, with the third stage as the main one. On the one hand, the housing shortage has not been effectively alleviated, and people have one side. On the other hand, most residents' demand for housing has shifted from quantity to the stage of paying equal attention to quantity and quality, and entered the era of pursuing personalized housing. As an important feature of the third stage, the impact of population suburbanization on the spatial distribution of Shanghai's housing industry can be analyzed from the following two aspects:

1, the spatial characteristics of urban residential layout

The spatial differentiation of commercial housing is the main feature of the evolution of residential spatial structure in central cities in the 1990s. From 1993 to 2000, in order to improve the living conditions of citizens, Shanghai invested a lot of money in housing construction every year, with a cumulative investment of1630.5 billion yuan. Since the 1990s, the residential building area in Shanghai has increased year by year, with a cumulative increase of 1, 993- 1, 998 reaching more than 60 million square meters, an increase of nearly 40%. In terms of distribution ratio, Shanghai's housing is mainly distributed in urban fringe and suburbs, accounting for more than 80% of the total urban housing area, while the core area only accounts for 10%. Judging from the growth rate (Table 5), the growth rate of residential buildings in the core area is obviously lower than that in the marginal areas and suburbs, and its proportion is decreasing year by year. From the data analysis, we can see that with the suburbanization of a large number of people, the layout of urban housing has also changed greatly, and a large number of housing construction is expanding outward along the core area-fringe area-suburb.

In addition, according to some statistical data of domestic commercial housing in Shanghai (Table 6), the approved proportion of pre-sale of commercial housing, transfer of residential transactions and transfer of stock houses in suburbs is above 70%, the proportion in marginal areas is above 20%, and the proportion in core urban areas is only about 1 ~ 3%, which fully shows that with the process of population suburbanization, suburbs have become the main places for people to buy houses. With the further standardization and marketization of the current real estate market, it can be predicted that suburban housing will have great development prospects. Moreover, we believe that with the further development of some suburban counties and the massive migration of population, the layout of urban housing in Shanghai will be further spread and suburbanization due to the development of finance, commerce and other industries in the core area.

Spatial differentiation characteristics of commodity housing prices

According to the decision model of urban housing distribution put forward by western scholars, the housing forms with different economic status present a fan-shaped layout around the urban commercial center; The living patterns of different family status present a concentric layout around the urban commercial center; Different races live in their own independent communities, which makes the life patterns of different nationalities in different positions show a state of dispersion and isolation. Under the condition of market economy, residents' economic income and family structure are the main factors in the spatial distribution of urban housing. Here we take the price of multi-storey houses as a reference. Due to the relatively strict volume control of multi-storey residential buildings in Shanghai, the correlation coefficient between multi-storey commercial residential buildings and land is relatively stable, which can accurately reflect the land grade difference in the location. According to the Shanghai housing price index, the housing prices in this city can be divided into several grades. With the development of Shanghai's population suburbanization, the housing prices in various districts and counties have also changed greatly: at present, houses with a price of more than 4,000 yuan are basically along the inner ring road (Zhongshan Ring Road), highlighting three areas in the southwest, namely Xujiahui area (Xujiahui to Jinjiang Paradise extends along the north side of the subway, that is, the western core area-marginal area-suburb), Hongqiao Gubei area (southwest along Hongqiao Road to Hongqiao Gubei area) and Pudong Lujiazui. Remarkably, these three prominent areas were not comparable to the core urban areas before the 1990s, but now they have become the hottest real estate investment and development intensive areas in Shanghai. The reason is that the development of population suburbanization is a very important part. It is precisely because these areas have accepted the first wave of population suburbanization (that is, these areas are the first choice for most people to flow out of the core city), so the real estate industry has grown rapidly here. From the data analysis, the prices of multi-storey residential buildings in the core city are basically above 5,000 yuan, because the core area is a mature plot with the highest land grade difference, and the land price per square meter reaches 8,000-110,000 yuan. In order to reduce the floor land price, we can only adopt high-rise high-volume ratio to spread the land price, which will sandwich the construction cost of the house, and the price per square meter of the house will still reach 5000-8000 yuan.

In a certain sense, the price has further improved the entry threshold for people to live in the core area and accelerated the suburbanization of the population. As can be seen from the benchmark map of Shanghai land price, in the area 5 kilometers away from the Inner Ring Road, the housing price has basically risen to about 3,000 yuan, with finger-like protrusions on both sides of major traffic lines, such as * * * in the north, Xinma Road and Southwest Subway. At the same time, in the Century Park area of Hua Mu, Yang Jing and Pudong, Zhangjiang, Liuli and Yanqiao also reached this price. We can clearly find a thread from the changes of population and population density in various districts and counties in Shanghai in the past 10 years mentioned in this paper: which region will develop rapidly and the housing prices in this region will increase geometrically. Think about the scene of "I would rather have a bed in Puxi than a room in Pudong", and then look at the current housing price trend in Pudong, and I have to lament the great influence of population suburbanization on urban development.

The above analysis of population suburbanization and urban housing distribution shows that the residential spatial structure of big cities in China is in the process of reconstruction. Government management departments should attach great importance to how to guide and rationally arrange urban living space.

Fourth, reflection on the suburbanization of population.

From our research and analysis of the population movement in Shanghai in the past 10 years, it is concluded that the essence of population suburbanization in Shanghai is population urbanization. Nowadays, many scholars believe that the important way of China's modernization development is urbanization. The author agrees that urban development is an important comprehensive development problem, but at the same time thinks that the formulation of urbanization is not safe, which is more in line with the development reality of China today. Because some big cities along the eastern coast, which have concentrated the essence of China's reform and opening-up achievements in the past 20 years, have entered the later stage of urbanization and are gradually entering the suburbanization of population, which is the road of suburban urbanization. At the same time, the suburbs also accept most of the floating population (including outside the district and rural areas), so the formulation of urbanization can better reflect the interactive relationship between cities and towns, and also better reflect the floating relationship between the two places. A large number of foreign examples prove that the promotion of urbanization plays a very important role in alleviating the contradiction between people and land in cities. It is a bright road for the city to achieve sustainable development, achieve the goal of harmonious and orderly urban society, economy and ecosystem, solve the situation of high housing prices and poor living environment in central cities, reduce the population of central cities, realize population suburbanization and increase urbanization. According to the author's research on Shanghai's urban development, we can draw such a development pattern: with the development of Shanghai's suburbanization, Shanghai's urban layout is not only the CBD (Central Business District) of Lujiazui and Bund in Pudong, but also the CBD of 30 square kilometers in the original core city. In the next 5- 10 years or so, Shanghai will form a number of new sub-central cities outside the inner ring: Minhang Xinzhuang in the southwest, Yangpu Wujiaochang in the northeast, Putuo Zhenru in the west and Hua Mu in the east, thus truly forming a sub-central city of Shanghai-a sub-central city (like Xujiahui)-a central core area. The population will flood into these areas in the next 5- 10 years. It is conceivable that the real estate industry, especially the residential industry, will flourish in these areas.

Increasing the intensity of population suburbanization needs the strong support of the government, especially: the process of population suburbanization should be the macro-led process of the government. China's urbanization process has lagged behind for many years, so we must intensify urbanization construction, speed up reform with the attitude of "now or never", and speed up the elimination of all man-made obstacles to urbanization. First of all, we should establish the concept of people-oriented urban construction and development. Development is the last word, but for population suburbanization and urbanization, what is development, what is its essence, what is its purpose and what is its symbol? We all have to grasp and understand. The lag of urbanization process lies in the problem of not grasping the concept of development in those years. Only talking about income growth and not talking about distribution relations, some substantive reforms have been delayed for 10 years, thus accumulating a large number of economic and social contradictions. In the development of urbanization, the first thing farmers have to solve is social security. Only by solving this problem, both the residents flowing out of the core cities and the residents flowing in from the countryside will have the same practical social security, and the road to urbanization will be smoother and smoother. Secondly, the government should clarify the distribution relationship by clarifying the ways of renting, paying taxes and removing fees. Rent, taxes and fees are the theoretical expression and conceptual connection of the distribution relationship between owners and users, government and market subjects. Rent is to find out the paid use of production factors, solve the problem of housing property rights, and reassure the residents in the suburbanization of the core area. At the same time, through open leasing, urban and rural elements will be capitalized and commercialized, and urban and rural areas will be in the same system and track, and urban and rural areas will be integrated. Positive tax means that all expenses required by the government to serve taxpayers must be clearly defined as tax. Taxation is a government act. Among all macroeconomic policies, tax law has the greatest impact on the real estate industry. At the same time, in order to transfer taxes, real estate developers will raise house prices and greatly affect population mobility. In addition to charging, that is, don't collect fees indiscriminately. Charging is a commercial act. In addition to normal taxation, it is not to engage in in in-price tax and administrative charge, but to separate taxes from prices and combine prices with fees. Finally, it is necessary to regionalize industrial policies and improve the concentration of urbanization. One of the greatest benefits of cities is agglomeration, which greatly reduces transaction costs. Therefore, with the acceleration of the process of population suburbanization, it is necessary to plan the development of cities and towns, further clarify the functional orientation of cities and towns and the characteristics of their respective industrial structures, and not follow the same model.