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.

Most studies on induced abortion have been conducted based on period data; an analysis from a life course perspective is needed. Based on the life course survey data of the China Health and Retirement Longitudinal Study (CHARLS) in 2014, this paper analyzes the lifetime pregnancy information of women born in the 1930-1969 cohort. The hierarchical APC model is used to estimate the period, cohort, and age effects affecting the level of lifetime induced abortion among women. The results showed that the period effects reflected the adjustment of family planning policies and the development of reproductive health services. Regarding cohort effects, the quantity and the sex selection mechanism for induced abortion differed among women from different cohorts. The age patterns of induced abortion showed heterogeneity and regularity across women in different periods and cohorts. Future policies should improve reproductive health services, reduce unwanted pregnancies, promote gender equality, and focus on the health status of middleaged and older women who have experienced induced abortion.

Drawing on data from the Life History Survey of CHARLS, this paper analyzes the migration history and gender differences of 1930-1969 birth cohorts in China, and examines the effects of major life events (education, employment, marriage and childbirth) using event history analysis. The results indicate significant cohort and gender differences. Compared with the birth cohorts of 1940-1949 and 1950-1959, cohorts of 1930-1939 and 1960-1969 experienced fewer policy restrictions at age 20-24. Therefore, these cohort groups show higher lifetime completed migration rates and larger gender gap. Education and employment opportunities increase the chances for lifetime migration, while early marriage and childbearing have opposite effects. Employment opportunities increase the chances for multiple migrations for women and narrow the gender gap in migration. Marriage and childbearing reduce the probability of subsequent migration, and divorce increases the probability of migration. The impacts of these three factors are bigger for women than for men.

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.