The phenomenon and issues of rural children left behind (RCLB) in China are affecting the flow of human capital between urban and rural areas. This paper clarifies the definition and steps for identifying RCLB, and uses the micro-data of the 2010 and 2020 Population Censuses to analyze relevant characteristics and changing trends over the past ten years. The analysis includes the following aspects: population size of RCLB, their age and sex structure, regional distribution, living arrangements, and educational development. The findings show that the population size of RCLB remained large, and the likelihood of being left-behind was closely related to age and sex. An increasing proportion of RCLB were cared for by grandparents as more mothers migrated between 2010 and 2020. RCLB no longer had any advantage in education opportunity compared with the average level of rural children. Over-age attendance was more noticeable among RCLB than the average level of rural children. We should continue to pay attention to the issue of RCLB and address its root causes.

Using the Global Bilateral Migration Database and the International Migration Stock Database, this paper examines the changing trends of international migration from China's neighboring countries between 1960 and 2020. It also explores the situation of migrants from neighboring countries to China and their future trends. In the past 60 years, both the stock of migrants from neighboring countries and the stock of neighboring countries' migrants to China decreased first and then increased. Meanwhile, the destinations of migrants from neighboring countries began to shift to Europe, America, and the Gulf countries, with differences existing among neighboring countries. During this period, although migrants from neighboring countries occupied an important position among all migrants in China, most migrants from neighboring countries did not migrate to mainland China. Considering China's future development prospects, it can be expected that China will face a larger scale of migrants from neighboring countries. Currently, adequate preparations are needed in academic research and policy-making.

Chinese population development has entered an era of long-term negative growth with various new characteristics, which will keep normalization. At this historical juncture, we need to have a comprehensive understanding of the overall situation of population development and cope with the problems accompanying negative population growth. To effectively handle the negative population growth, we propose a ”quality, allocation, and openness” human resources development path. To be specific, we need to make the most of the population quality dividend, optimize the human resources allocation in accordance with the trend of population flows, and attract overseas intellectual resources by approaching the international human resources market.

Based on the national census data since 1982, combined with the methods and indicators such as migration participation rate, visibility of floating population, distribution of floating population, and interprovincial migration flow, this paper comprehensively summarizes the spatial development of floating population from the perspectives of departure areas, destination areas, and flow directions. Meanwhile, the paper further discusses the evolution and recent characteristics of China's migration transition based on the gender structure, age structure, educational structure, urban and rural structure, the separation of living place and household registration, the migration of ethnic minorities, and the situation of crossborder migration. The results show that high population mobility has become the new normal of China's population characteristics. The process of migration transition varies across different regions, while some regions has already entered a new phase of migration transition. During the past 40 years, the internal structure of China's floating population has changed rapidly, and the new characteristics have started to emerge. China's migration transition has been and will continue to be a comprehensive, multi-level, and diversified process.

Interethnic marriage is of great significance to construct the pattern of ethnic embeddedness and create a strong sense of community for the Chinese nation. Through exploring the data of the national censuses and 1% population sample surveys since 1982, this paper summarizes ten major trends in interethnic marriage in China since the reform and openingup: the universalization of interethnic marriage with a substantial increase of the population and proportion of interethnic marriage; the relative differentiation of interethnic marriage among ethnic groups; the expanding of interethnic marriage circle with the subcircles blending with each other; the relatively deep degree of interethnic marriage in northeast and southwest areas; the positive impact of urbanization on interethnic marriage; the promotion of interethnic marriage by migration; the steplike sex ratio difference; the improvement of womens family status; the positive correlation between education level and interethnic marriage; and the stratification of occupational types.

According to the 7th Population Census, the size of the floating population has further grown; the urban attraction to floating population keeps increasing; the floating population has become the leading factor of urban population growth; urban to urban population migration has expanded; the floating population is still highly concentrated to move to the eastern region; population who live in places other than their household registration areas has strikingly increased; the international immigration has steadily grown. In summary, highly active population movements in China get further confirmation.

Changes in the international migration calls for further research. By reviewing the history of international migration transition, we find that the flow, direction, and structure of international migration have undergone remarkable changes towards a larger scale and more complex structures. At the same time, although Chinas international migration has fluctuated, the number of international migrants either from or to mainland China has increased constantly. It is expected that with the deepening reform and opening and “The Belt and Road” initiatives, the scale of China's international migration will keep growing. China will transit from a state with few international migrants and limited knowledge about international migration towards a state with large-scale international migration which needs more understanding towards international migration and related affairs. To enter the incoming era of large-scale international migration, China should systematically collect the information of international migrants, work out the details of relevant laws and regulations, carry out international migration perspective assessment on major economic, trade, diplomatic and other strategies, and establish targeted migration plans.

The low spatial population mobility has been the demographic characteristic of Rural China for thousands of years. In the past 40 years, China has experienced and is experiencing the transition from a Rural China with few migrations to a Migrating China with large-scale and high-frequency migrations. The historical transition from the Rural era to the Migration era is realized in a short period of 40 years, which has its internal mechanism, including the reform of the land system, the change of population structure, the development of urban market economy and the loosening of migration policies. This will enable high population spatial mobility to be continued into a long time in the future. In adjusting to a Migrating China, relevant cultural construction and cultural adaptation play an important role. It is necessary to gradually move from a Static Culture adapted to Rural China for thousands of years to a Dynamic Culture adapted to Migrating China.

Using data from China??s population census and one-percent national population sample survey since 2000,this paper analyses the changing patterns and challenges of child population in China. Results indicate that the child population has stopped decreasing and shows a sign of stabilization.Meanwhile,the number of children who grow up in urban areas is increasing while the rural number continues dropping. The proportion of ethnic minority children maintains a continuous growth. The proportion of families that have no children is also increasing. In contrast,the proportion of multi-child families keeps reducing. The living conditions and development chances of children are facing several challenges,including a large number of floating and left-behind children,especially the urban left-behind children,which have been gradually expanding. The imbalance of children??s sexual structure is also striking. Family care becomes an emerging problem and the compulsory education of children still faces severe challenges. Finally this paper discusses policy implications regarding poverty relief,market-driven family care system,and the educational problem of children.

An increasingly evident trend in China’s urbanization is the“Urbanization of Poverty”． Migrant workers，especially those leaving both their farmland and hometown have become the main body of the new urban poverty population．Prior poverty studies focus more on“survival”but less on “development”and“risk”of the migrant workers．Based on the scarcity theory and the risk society theory，this paper puts forward a three dimensional framework of“Survival-Development-Risk”for poverty analysis．Empirical analysis using data of 2008 Floating Population Income Survey shows that the majority of impoverished migrant workers suffer from meager wage，hindered development，as well as lack of social insurance，and may easily fall into risky poverty．In addition，their subjective feeling of deprivation is also higher than the non-poor．This study also identifies variables，including gender，education level，job type，occupation and region，that have significant effects on poverty．

This study  analyzes the trends and current  characteristics of floating population  in  China  and the major  challenges they  are facing ，on the basis of  the  latest  population  census  data． The  research  shows that the  size of floating population has increased continuously  and rapidly ，their mobility  intensity  is weakening ，migration  destinations  are  beginning  to  decentralize ，majority  of  the  migrants  are  moving  with  their spouses and more and more of  them are taking their young children with them ，the new － generation floaters whom were born  after  1980  account for  more than half  of  the  entire floating population． The floaters are fa- cing challenges such as unemployment ，lack of social security ，inequality in children ’s education ，and bar-
riers in  social  integration． This article proposes corresponding  suggestions． The problem of  new － generation floaters and floating children  should be addressed adequately ，and there  is an  urgent  need to  accelerate the establishment  of  social  security for migrants． 

China’s urban population exceeded rural population for the first time in Chinese history,reaching 51.27% in 2011.However,the level of urbanization has been exaggerated.If deducting the landless peasants under forced urbanization and migrant workers being not treated equally in the cities,China′s actual urbanization level stood at 41.6%.There are challenges ahead.For example,an urban social value system has not established in our society;we don′t have a clear understanding of the role of cities and how to develop a city;urban management has not prepared well for urbanization development;and there is a long way to go in achieving equal treatment for all of the Urban residents.To cope with the challenges of urbanization,we need to improve the quality of urbanization,correctly understand the role of urbanization and its substance,follow the law of the urban development,and to explore building of an urban culture system.

China has been urbanizing and big cities have been growing rapidly.Number of megacities in China increased from 34 in 1997 to 63 in 2007.There are substantial disputes over China’s urbanization strategy to prioritize big cities or medium and small-sized cities.Development of big cities faces challenges in transportation,housing,environment and resources and public services,and population control becomes increasingly important in big cities.This issue of Population and Development Forum is specifically devoted to population control in China’s megacities,for which three population experts were invited to share their views and suggestions.Professor Huang Ronglong,from Nanjing Normal University,argues that the major cause of China’s urban disease is not overpopulation but ill management of the cities.However,Professor Ding Jinhong,from East China Normal University,has a different view and asserts that a permanent cure to urban disease is population control.Talking on population control in Beijing,Professor Duan Chengrong,from People’s University of China,suggests the population control strategy be changed from a local to a national perspective.Three experts also provide policy suggestions in population control,city planning and management,industrial upgrading,mechanisms in evaluating demographic effect of social and economic programs,etc.Professor Liu Feng,from Development Research Center of the State Council,chairs the Forum and provides comments to the three papers and his own opinions as well.

Using data of Chinese censuses in 1982,1990,2000 and 1% sample survey in 1987 and 2005,this paper analyses the distribution trends of floating population in China at region,province,and city levels.Distribution of floating population presents obvious central tendency.From regional perspective,the floating population increasingly concentrated in the eastern region,the eastern and southern coastal areas.From provincial perspective,floating population increasingly concentrated in few provinces.The first five largest migration destination provinces absorbed half of the country’s floating population.From city perspective,floating population increasingly concentrated in a few cities,showing outstanding polarization.In the early 21st century,there is an emerging city band comprising 35 coastal cities,absorbing more than half of the floating population in China.Distribution concentration trend of the floating population will continue,which constitutes the prerequisite for policy making regarding the floating population.

Large-scale labor migration in the past two decades in China has reshaped the household structure of migrants,generating numerous "stay children" and migrating children with or without parent(s).Stay children and some migrant children live in nontraditional households without parent(s)’s immediate,which would have profound implications for their education.Drawing on the 2000 Census data,this paper explores the patterns and characteristics of school attendance,and compares the educational opportunities of stay,migrant,and other children(living with parents) ages 11-14 in the countryside.Analytical results suggest that stay children are more likely to enroll in school than other types of children,but such effect varies by whom the children stay or migrate with:those staying with mothers are most advantaged,while those migrating alone or with parents mostly disadvantaged.It is thus urgent to promote the educational wellbeing of children in father-child families and of migrating children.

Using data from the one per thousand floating population survey in Beijing conducted in 2006, this paper examines structure, distribution, economic status and living arrangement of the floating population in Beijing. Structural changes of the floating population are taking place, with increasing familization of migration. Economic advantages are the major pulling factor in Beijing. Duration of stay in Beijing is quite long for most of the migrants, and many are the de facto Beijingnese. Being informal is characteristic of the ways in which the migrants move to and are being employed in Beijing. The vast majority of the migrant workers are engaged in non-agricultural activities; however, their upward mobility in the city is rare. The paper also discusses difficulties and problems that the migrants face in employment, social security and living conditions.