Analyze the relationship between age structure and population change process

Since 1980s, the achievements of studying China's population migration and urbanization from different disciplines have emerged rapidly. As an important practical problem under the condition of dual economic and social transformation, the rapid urbanization of China in recent years and the large-scale migration and mobility of rural population to cities are and will continue to have a far-reaching impact on economic development and social integration, which also determines that the migration and urbanization of contemporary China will be one of the most dynamic fields in population and development research for a long time to come.

In recent 20 years, the research on population migration and urbanization in China has made remarkable progress, but it is still immature in theoretical construction and research methods. It is time to review and summarize the research on population migration and urbanization itself after the rapid development of early quantity. This paper will review and summarize the materials published in Chinese academic journals from China (Mainland China) 1978 to 1998. The data source is mainly based on the topic of Demography ② in the Information Center of Books and Newspapers of China Renmin University, and the key words in the topic are searched. In addition, some papers that are not included in the demographic topic are supplemented. As a result of migration studies, in particular,

Firstly, the research on population migration is briefly reviewed.

Since the late 1970s, population science in China has entered a golden age of vigorous development. Decided by the macro background and policy needs, the early population research focused on population reproduction, and there was little research on population migration and flow. Only some information about foreign migration and policies is scattered in various journals.

Under the highly centralized planned economy system, population migration, especially the labor migration and allocation of non-agricultural industries, has been brought into the national plan, which fundamentally denies the important role of free migration of population in the allocation of production factors, and the research on population migration and labor mobility is almost blank. After the reform and opening up, with the promotion of rural reform focusing on the contract responsibility system, the externalization and transfer of rural surplus labor began to become a research hotspot, and gradually expanded to related issues and disciplines, forming a research pattern spanning economics, geography, sociology and other disciplines. The rapid increase of floating population in cities has strengthened the concern of government departments and scientific research institutions on floating population. Since the mid-1980s, several megacities in eastern and central China have successively carried out surveys on floating population. 1990 the fourth national census comprehensively investigated the population migration in China for the first time, which provided strong data support for migration research. Since the 1990s, policy research departments and academic research institutions have made a continuous and in-depth investigation and study on the "migrant workers' tide" which began to have a strong impact on society in the late 1980s. Its research methods and main achievements have strong economic and sociological characteristics.

Qiu (198 1) published a preliminary study on population migration since the founding of the People's Republic of China, which is the first paper that can be retrieved to study population migration in contemporary China. From 198 1 to 1983, only five research papers on migration and mobility were retrieved. From 1984, the research on migration and mobility began to develop rapidly: 1 1 papers were retrieved from 1984, and 22 papers were retrieved from 1985. 1988 became a climax of migration and mobility research, 4. 1995 reached a new climax with 65 papers. From this, there are roughly three stages: the initial stage is 198 1 to 1987. At present, the information about migration and mobility is extremely scarce, and the research theories and methods are also very weak. Therefore, the paper is mainly a general analysis or a small-scale investigation, but this stage has laid the foundation for the later development. As for the monograph, Tian Fang's Population Migration in China (1986) systematically summarizes the main migration activities from the founding of the People's Republic of China to the mid-1980s, including development migration in border areas, reservoir migration and population self-flow. Hu Huanyong's Population Geography of China (1984) and Sun Jingzhi's Population of China (1987) both have special chapters on population migration, which provide an important analytical framework and data basis for the following population migration research. Li Debin (1987) summarized and analyzed the spontaneous or organized immigrants who moved to Heilongjiang after liberation in the early 1980s, which is also of great value. The period of 1988- 1995 was a great development stage of population migration research, and the research results emerged rapidly, initially determining the framework position of population migration and mobility research. Apart from the requirements of discipline development, there are several favorable factors for the great development of this stage: on the one hand, since the mid-1980s, the mobility of the population in China has been greatly enhanced, which requires academic circles to conduct special research on this issue; On the other hand, the data conditions have been obviously improved, such as the series of "China Population", the collation and publication of statistical data of household registration migration, the "74 Town Migration Survey" sponsored by the Population Research Institute of China Academy of Social Sciences, the "Floating Population Survey" in some megacities, and the national sampling survey of 1.990, all of which are migration studies. Comprehensive utilization of relevant data, such as Li Meng Deng Bai (199 1), makes a comprehensive summary and analysis of the floating population in big cities. Yang Yunyan (1994) made a detailed analysis of population migration mainly by using the sampling data of the fourth population census. Peng Xun et al. (1992) theoretically discussed the disciplinary system of population migration. Since 1996, the research on population migration has been deepened, and the expansion of research results has been obviously slow, but some progress has been made in the innovation of research methods, the introduction of foreign research methods and interdisciplinary research.

Judging from the research content, it covers a wide range of contents. Among them, it can be divided into three parts: the first part is a comprehensive research paper on migration, accounting for about 37% of the total, including the situation, process, flow direction and structural characteristics of national or regional population migration, and the general theory and methods of migration; The second part is about the research results of floating population, temporary population, "migrant workers" and other topics, with the largest number, accounting for about 47% of the total, of which a considerable part is about the ideas and suggestions on floating population management, including the family planning management of floating population. The third part is special research, including environmental migration, development migration, reservoir migration, marriage migration, transnational migration and mobility, accounting for about 16%.

Second, the main progress of migration research

After nearly 20 years of research and discussion, we have basically clarified the process, basic characteristics and main mechanism of population migration and flow since the founding of the People's Republic of China. People began to deeply discuss the complex social and economic impact of immigration, and initially tried to introduce and improve foreign research theories and analysis methods. The management and strategy of migration and mobility are discussed extensively, and its main progress can be analyzed from the following aspects.

1. Basic information of population migration and mobility: As a complex socio-economic phenomenon, population migration plays an important role in economic development and population distribution. But for a long time, we have always lacked a clear understanding of China's population migration. Due to the lack of direct data, some cases can only be judged by indirect calculation, especially in early research. Revenge for it (198 1) According to the changes of population growth rate and population proportion in various provinces and regions from 1949 to 1979, this paper investigates the population migration from the founding of the People's Republic of China to the end of 1970s, and summarizes two inter-provincial migration modes: organized migration and spontaneous migration. It is considered that there are three main immigrant areas, namely, the lower reaches of the Yellow River and the Yangtze River. This paper also draws the migration direction (schematic diagram) for the first time. At that time, when information was extremely scarce, it was not easy for this article to accurately describe the situation of population migration in China. Wei Jinsheng (1984) and Jasmine Zhang V (1988) analyzed the definition of population migration in China and discussed the definitions of "migration" and "mobility". Wei Jinsheng defines migration as "all kinds of population movements with demographic significance that occur between different provinces, autonomous regions or counties (cities and municipal districts) and between economic regions and natural regions". This division is widely used in statistics, investigation and research of population migration and mobility in China. Ma Xia (1987) reflected the migration from 1954 to 1984 for the first time, which is a great progress in the overall research, but the data from 1966 to 1968 used in this paper are incomplete (Yang Yunyan 60 Yang Yunyan (1992) used 1987 1% population sampling data and 1990 census data to calculate the change of migration scale since the reform and opening up, and thought that the migration direction, mechanism and types had been greatly reversed after the reform and opening up.

But up to now, the research on population migration and mobility still shows some confusion, which is first reflected in the concept definition and statistical caliber of population migration and mobility. For example, population migration is limited to those who have completed household registration migration, and all floating population who have not completed household registration migration procedures are called "floating population"; The functional short-term resident or transit population in cities and towns and the permanent population with employment and settlement are also collectively referred to as "floating population" and so on. Because of the confusion of definition, it is difficult to conduct investigation and statistics. On the one hand, we have obtained in-depth and detailed information about population and labor mobility, on the other hand, even the most basic aggregate indicators have not been determined so far. Although the relevant departments have released some materials, these materials are of low quality, with different calibers and often without comparability, so it is impossible for them to sort out continuous materials. The population migration information released by the public security department not only has statistical quality problems, but also has limited coverage. Only the part of the population with household registration migration is included, and its proportion in the total population even shows a downward trend, which is inconsistent with the reality that China's population mobility has greatly increased since the 1980s (Yu Shu et al. 1998). Regarding the temporary population, the statistics of urban temporary population published by the public security department are too wide, and the phenomenon of missing reports is more serious. Population census and national sample survey are mostly stock indicators, and the caliber has changed, which affects the comparability of data.

2. Floating population and "tide of migrant workers": Generally speaking, floating population refers to those temporary population movements, but in the current situation, "flow" is often used.

The concept of "population" includes all population movements that have not gone through the formalities of "household registration transfer", regardless of whether such movements are short-term or long-term. According to the data, there are actually two types of rapidly increasing population movements at present: one is urban functional floating population, which increases with the economic development and their stay in cities is generally short. The flow direction of this kind of floating population is determined by urban function and urban radiation range, and its temporal and spatial distribution is relatively balanced; The other category is the labor force that enters the city to look for job opportunities. This kind of "floating population" is large in scale, stays in cities for a long time, and the mobility is relatively concentrated, which causes great social shocks. The latter is usually called "temporary population" or "foreign population" according to the household registration status. Because this special group conforms to the basic characteristics of population migration in demographic research, they are also regarded as a special form of migration, that is, "informal migration" compared with "planned migration", and their difference from planned migration is mainly reflected in their household registration status. Because registered permanent residence still plays a fundamental role in urban social and economic life, "informal floating population" can't enjoy the same opportunities and rights as "regular" urban residents to obtain means of subsistence and means of production, thus forming different immigrant groups with different registered permanent residence status in employment opportunities, industry and occupational mobility, welfare and social security (Yang Yunyan 1996).

"Irregular immigrants" existed in the planned economy period. Li Debin (1983) discussed the self-flow of population to Heilongjiang during the planned economy period. Chen Yu (1984) used the data of the third census to study the situation of "separation of people and households" for the first time, and Zheng Guizhen (1985) conducted a comprehensive survey of floating population in Shanghai for the first time, and estimated the floating population to be 700,000. After that, the investigation, analysis and articles about the floating population in cities and towns emerged rapidly. Bai et al. (199 1) made a comprehensive summary of this, and Chen Xianshou et al. (1996) pointed out the trend of "immigration" and "family" of floating population in recent years.

Since the 1990s, the cross-regional flow of rural labor force, that is, the "migrant workers' tide", has become a research hotspot. These studies mainly have two directions: one is to study the transfer of surplus labor force and the "temporary population" in cities and towns from the perspective of rural labor force flowing to cities and towns; First, from the perspective of cross-regional mobility, study the problem of "migrant workers' tide" or "migrant workers' tide" (Central Political Research Office 1994). The research in this field has gradually deepened from some static demographic characteristics, such as mobility, age, gender, education level, industry distribution, professional status, marriage and family, to social and economic dynamic characteristics, such as the mobility process in the inflow place, income and consumption, changes in behavior patterns, social conflicts and integration (Han Xiaoyun 1995), and the impact of labor outflow on the capital and family in the outflow place.

3. Migration selectivity, migration mode and mechanism: there are generally regular or universal structural differences between immigrants and non-immigrants, which can be considered as migration.

The result of immigration "choice" is the selectivity of migration. Some foreign scholars question whether there is selectivity in population migration under the planned economy environment in China. In fact, the selectivity under the planned economy may be more prominent, but the selection mechanism will be different. Because China has long adhered to the policy of controlling urban population growth and non-agricultural population growth, the state basically does not restrict the population moving into rural areas, including urban suburbs and rural areas (engaged in agricultural production), so it is easier to settle down and complete the household registration transfer procedures. Strictly select the population moving into cities and towns, and give priority to the professional and technical personnel urgently needed for urban economic development. In the way of migration, it is mainly the planned deployment of cadres and the enrollment and distribution of colleges and universities. Therefore, the planned migration policy shows obvious selectivity in the source, structure and destination of the migrated population. Planned migration mainly involves highly educated professionals and state cadres, and flows into state administrative institutions, large and medium-sized state-owned industrial enterprises and advanced service industries, mainly engaged in mental work or technical occupations. Among all migration selectivity, age is the most common. Generally speaking, young people have an obvious tendency to migrate, and the floating population is obviously concentrated in the age group of 15 ~ 35. As early as the early 1980s, related surveys confirmed this phenomenon. According to the survey of Jiping (1983), 74% of the people who moved to Beijing are of working age, and most of them are under 30. Li Yu et al. (1984) found during the period of 1980 ~ 1982 that the proportion of working-age population among the migrants in Beijing was as high as 93.2%. The gender selectivity of migration changes with the nature of migration, and some types of migration have obvious gender selectivity. For example, marriage migration is influenced by history and tradition, and most of them are women. 1987 national 1% sampling survey shows that women account for 93.3% of the marriage transfer, and the sex ratio is as low as 7.2, basically women dominate the world. It is the high selectivity of this migration in gender composition that makes the unbalanced marriage migration likely to have a far-reaching impact on the place of immigration and the place of emigration (Yang Yunyan, 1994). The relationship between immigration education and immigration is also an important aspect of immigration selectivity. Judging from the situation in China, the average education level of immigrants is generally higher than the national average. This is closely related to the planned migration of college enrollment, distribution and cadre deployment in China, but the opposite situation is found in the rural labor flow (Zhao 1997).

Wang Guixin (1993), Liu Qiming (1992) and Ding Jinhong (1994) discussed the spatial pattern of inter-provincial population migration, especially the important role of distance in the migration direction. Yan Shanping's (1998) land use interval migration model investigates the influence of migration stock and economic development level difference on inter-provincial migration. There are also some studies that use western economic analysis methods to discuss the mechanism of labor mobility (Cai Fang 1997).

4. About the migration effect: Because of its spatial imbalance and structural selectivity, population migration has many influences on the places of immigration and emigration. First of all, population flow directly changes the total population of the place of immigration and the place of emigration, and indirectly affects the population contrast between the two places through the transfer of fertility; Secondly, the change of fertility behavior caused by population mobility will change the population reproduction mode of the two places; In this way, the distribution and development mode of population will change; In addition, the population movement will change the population structure of the two places. There are two kinds of changes in population spatial structure caused by population movement: agglomeration migration will strengthen the imbalance of population distribution, and diffusion migration will make population distribution tend to be uniform. The regional mobility of population and labor will also have an impact on regional differences (Cai Fang 1998).

Population mobility will also have a direct impact on the ecological environment. In ecologically fragile areas, population migration may aggravate the deterioration of the ecological environment, especially the unreasonable use of environmental resources in agricultural migration has caused serious consequences, but there are also a few cases where the ecological environment has been improved through scientific management after population migration.

The social impact of population mobility is a problem of particular concern. In the process of reaching a balance, the population flow constantly breaks the old balance, resulting in multi-level friction. In the long run, this social integration process is conducive to enhancing the vitality of society, while in the short run, it may bring social problems, such as cultural conflicts and crimes. The adjustment of immigration behavior is an important part of the micro-social effect of population mobility. The differences in values and behaviors of immigrants who flow from one cultural background and a specific community into another behavior and cultural atmosphere force immigrants to make adjustments in the conflict, and their behaviors and values may also affect the indigenous people who move in. Immigrants have formed a vibrant immigrant culture through the exchange and integration of various cultures, and in other cases, it may also lead to social conflicts. Generally speaking, immigrants who are in a minority position or with backward cultural background are more likely to adjust their own behaviors and values to actively or passively adapt to the lifestyle of the place where they moved in and be assimilated. When immigrants are in the majority, they may impose their own culture on immigrant areas. In immigrant areas, indigenous people may adopt a friendly or admiring attitude towards immigrants with relatively advanced cultural background, while they tend to adopt a discriminatory or even hostile attitude towards immigrants with backward cultural background. In this respect, more attention is paid to the research on the changes of women's marriage and childbearing behavior (linford et al. 1998), and these studies will be more valuable if they can be combined with the comparison with the places where they moved out.

At present, the impact of "floating population" on the labor market in the inflow area is not only a complex academic issue, but also an important practical issue. Fearing that the "foreign population" will affect local employment, some regions, especially megacities, have introduced policies and regulations to intervene in the employment of foreign population. Ding Jinhong (1995) and Zhao Min (1995) analyzed the employment of migrant population and its influence on urban labor market, and thought that the influence of migrant labor on local employment was limited. Chen Hao (1996) discussed the positive and negative effects of labor outflow on rural development.

5. On Policy and Evaluation: The editorial department of Population Studies organized a special discussion on the issue of floating population (1997). Generally speaking, academia and society

The attitude towards the floating population has changed from being more exclusive to being more tolerant. Liu (1995) made a detailed empirical analysis of floating population management. The policy evaluation related to immigration mainly focuses on immigration, household registration management system and urbanization policy.

In terms of development migration and environmental migration, after the founding of New China, China carried out large-scale development migration, environmental migration and reservoir migration. The idea of emigrating to remote areas has always been the mainstream. In the article (198 1), it is proposed to continue to emigrate to the west, and Wang Xun (1984) even proposed a specific scale. However, the idea of moving to the northwest has been criticized by the population geography circle (Huarong 1985), and the evidence about water resources constraint is the most convincing. The evaluation of northwest immigrants also indirectly supports these criticisms (Chen Bomin et al. 1988). In the late 1980s, the concern about emigration to the northwest was replaced by environmental emigration (Xie Shusen et al.1988; Zhang1995; Zhang Zhiliang 1995). Reservoir migration, as an important organizational migration, has been attached great importance by relevant research institutions (Zhang Siping 1983). In particular, the immigrants from the Three Gorges Project have attracted much attention (Helping Agriculture 1995). 1998 The catastrophic flood in the middle and lower reaches of the Yangtze River has put forward new tasks for the resettlement work.

On the status and function of the so-called "floating population": In this respect, further breakthroughs are needed in theoretical and empirical research, such as the legal status of the floating population. The equal labor right of workers is the basic right protected by the Constitution, and the discriminatory policy against the so-called "foreign labor" undoubtedly violates this equal right. The word "foreign labor" itself contains a strong color of planned economy, even discriminatory. What is the legal basis and theoretical explanation for restricting the employment of non-local registered workers? At present, the discriminatory treatment of so-called "foreign labor" has neither sufficient legal basis nor the basic principles of market economy. Secondly, our understanding of the labor market is very limited, and the impact of foreign labor on local labor supply, wages, overall economic operation and the creation of new employment opportunities is quite complicated. At present, under the discriminatory policy environment, most of the "migrant workers" can only engage in low-income and manual jobs under the harsh conditions in cities and towns. Some of their limited wages are collected by the government as compensation and returned to the subsidies of urban workers, while urban (local) workers use their favorable institutional position to "rent-seek". Under this institutional arrangement, even if the "foreign population" does a good job, it is hopeless to integrate into the urban community. The long-term policy of protecting cities has limited the opportunity for rural population to share the welfare improvement brought about by economic development. As the "last bastion" of the planned economy, the household registration system has always been very strong and obvious in its incompatibility with economic and social development.

Thirdly, the urbanization process of China and its research.

Compared with population migration, urbanization has been concerned earlier. This is mainly because urban science is still struggling to survive when population science is put in the cold, thus accumulating the foundation for the rapid development of urban science since the reform and opening up. However, the research on urbanization, like the urbanization process in China, is still full of twists and turns.

The 40-year urbanization history of New China can be roughly divided into five stages (Wei and Jin Dynasties 1985): 1949 to 1957 is a period of rapid and healthy urbanization. During this period, the proportion between urban and rural areas and between industry and agriculture was relatively coordinated, and the urban population increased from 57.65 million to 99.49 million, with an average annual growth rate of 7. 1%, which greatly exceeded the growth rate of the total population in this period, making its proportion in the total population rise from 65.438+00.6% to 65.438+05.4%, thus significantly shortening China. At present, the main factor of urban growth in China is the migration of rural population. Although the average natural growth rate of urban population at that time was as high as 3%, exceeding the rural population, it only accounted for 44% of the urban population growth, and 56% of the growth was achieved by migration.

1958 to 1960 is the rapid development stage of urbanization. Due to the rush for success and subjective assumptions in economic construction, China's industry and urbanization have developed at an ultra-high speed on the basis of breaking away from the level of economic development, and the proportion of urban population in the total population has risen to 19.7%, from 19654, 38+0 to 1965, which is the first anti-urbanization stage since the founding of the People's Republic of China. With the great adjustment of the national economy, the urban population has been greatly reduced, and about 30 million people have been mobilized to return to the countryside. By the end of 1965, the urban population was close to the level of 1957, but with the growth of the total population, the proportion of urban population decreased. This kind of anti-urbanization is a correction to the excessive development in the early stage.

The period from 1966 to 1977 is a period of great convection between urban and rural population. On the one hand, due to the beginning of the "Cultural Revolution" in this period, there appeared a reverse urbanization movement characterized by educated youth "going to the countryside" and cadres' decentralization. About 30 million urban educated youth, workers and their families, and people with "political problems" were forcibly moved to the countryside. On the other hand, urban enterprises and institutions recruit a large number of workers from rural areas. Due to chaotic management, many rural people have become urban population through various channels, with a total of more than 20 million. After the balance of entry and exit, the urban population moved out by about 5 million people. In terms of industrial construction, although the "third-line" construction aimed at preparing for war has promoted the macro-layout of productive forces to a certain extent, infrastructure investment has not formed the ability of cities and towns to absorb non-agricultural industries. During this period, the urban population growth in China was extremely slow, and the level of urbanization even declined.

Generally speaking, the urbanization level of China is not only lower than that of developed countries with the same level of industrialization, but also lower than that of developing countries with the same level of development. In other words, compared with the general level of urbanization, China is characterized by "insufficient urbanization".

The violent fluctuation of urbanization in China is closely related to the fluctuation of our understanding of urbanization. There have always been two opposing views on the role of urbanization in the process of modernization: one holds that urbanization is an important manifestation of modernization, and the other holds that urbanization is a "disease" brought about by development. For a long time, anti-urbanization thought has a far-reaching influence in China, but China's anti-urbanization thought is different from that in the west, and its particularity is mainly manifested in the following three aspects (Gu Shengzu, 199 1):

First, eliminate the idea of "three major differences". This idea hopes to eliminate the differences between urban and rural areas, workers and farmers, and mental and physical labor, and form the main basis for anti-urbanization in restraining urban development and realizing the so-called urban-rural integration.

Second, the thought of natural economy. Due to the narrow understanding of material production, the function of urban tertiary industry has been greatly weakened, and urbanization cannot be promoted.

Third, the class thought of urbanization. Some people think that "it is a unique law of capitalist society that industrialization leads to urbanization". Socialist countries don't necessarily have to follow the old road of capitalist social development to realize industrialization, but China needs industrialization instead of urbanization.

Chen Jinyong (1990) analyzed the urbanization road of China from the perspective of economic development strategy. He believes that the urbanization process in China has been relatively slow for quite some time since the founding of the People's Republic of China. Judging from the whole urbanization process, the growth rate of urban population in China is obviously lower than that of industry, heavy industry has been developed prominently in the urban industrial structure, and the urban system as a whole is also obviously inclined to large and medium-sized cities. This urbanization model corresponds to the socialist industrialization model, which is a major feature in the early stage of socialist urbanization. The urbanization process of the whole eastern European group has slowed down to varying degrees: in the 1950s, the urban population growth rate of the Soviet Union was relatively high, from 1950 to 1955, reaching the level of 3.9%, and then tended to decline; Eastern European countries have a similar situation, and the growth rate is even lower than that of the former Soviet Union.

According to the general law of development, the expansion of industrial sector will lead to the increase of urban population, which is more obvious in the early stage of industrialization, because the growth of industry depends on the increase of labor force. For developing countries, due to the difference in living standards between urban and rural areas, the motivation for rural population to flow to cities is very strong. Therefore, the industrialization of a country will have a guiding role and an important impact on the urbanization of its population. Socialist countries have also experienced such a process in the process of industrialization, but because of the different strategies of developing economic base in socialist countries, the urbanization of population in socialist countries has its own characteristics.

First of all, we can look at the industrialization strategy of socialist countries. Summarize the characteristics of socialist industrialization, mainly in the following aspects:

1. High accumulation rate and high growth rate. Due to the limited available external funds, the high accumulation rate can only be achieved by greatly reducing domestic consumption.

2. Mainly heavy industry.

3. Sacrifice agriculture. Industrial investment is mainly supported by the accumulation of agricultural sector, and the purpose of reducing the cost of industrial products and maintaining high-speed industrial growth is achieved by sacrificing agriculture.

In order to ensure the rapid development of industry, the process of urbanization in socialist countries has been greatly suppressed, because urbanization will improve the overall consumption level of the country, mainly in the demand for urban infrastructure construction and the "minimum feasible" living standard of cities higher than that of rural areas. The main measures to reduce the speed and "cost" of urbanization are as follows:

1. Restrict the growth of urban consumption, compress the development of service industry, and concentrate on the development of industry.

2. Strictly control the growth of urban population, mainly in controlling the inflow of population into cities.

3. Encourage rural industrialization, so as to achieve the goal of industrialization and avoid urbanization.

The impact of implementing the above development model is remarkable. Judging from the employment structure of urban labor force, the general trend is that with the development of the city, the proportion of industrial population increases, the proportion of service population remains unchanged or even decreases, and the proportion of unemployed population drops sharply. In the industrial structure of urban labor force, agriculture and tertiary industry are weak and industry is prominent.

The fluctuation of urbanization level is mainly realized by the difference between population migration and natural growth rate. There is no exact statistical data for the part of urban population in China that moved in by rural population, and it can only be estimated by indirect data. This indirect estimation is quite complicated because it is influenced by a large number of administrative divisions and statistical caliber changes. Many scholars at home and abroad have done a lot of work in this field, and here we will summarize several representative materials.

Ma Xia (1987) first calculated that the cumulative net migration population from rural areas to cities and towns reached 73 million from 1949 to 1986, accounting for 39.5% of the total increase. Subtract natural growth, net migration and indirect migration from the total urban population, and the urban population is 50.08 million, accounting for 27.0%; Regarding the indirect migration population, he multiplied the cumulative number of people who moved into cities and towns over the years by the natural growth rate of urban population in the corresponding years to get the number of people who moved in over the years. /ca & gt；