Several new developments in the economy, government policy, and technology warrant a revisit on the population issue in China. First, in 2015 the Chinese government announced that it would allow couples to have two children. Second, anecdotal evidence suggests that many wealthy and middle-class Chinese are migrating from China to developed countries such as North America, Europe, and Australia. Third, the rapid development in medical sciences and artificial intelligence is fundamentally changing how the elderlies live and are cared for.

All these changes call for a revisit on the issues of population in China. We need to carefully re-consider from scientific point of view the following questions:

1. What are the population problems in contemporary China? Is population growth a problem? If it is, in terms of what--population size, birth rates, death rates, age composition (fraction of working age, working, elderly, retired, school age, military age, etc.), sex ratio (at birth), marital status, educational attainment, health, migrant origin, urban-rural, ethnic, reproductive health services, food, water and other critical inputs, waste removal capacity, general environmental situation, etc.?
2. What is the impact of the new two-child policy? What is its effect on fertility rate? Is it effective in slowing down aging? Does it change people’s attitude toward having children?
3. What is the impact of Chinese migration on China and the world? What is the magnitude of wealthy and middle-class Chinese migrating to the developed countries? What is the impact of such migration—economic, political, and cultural—on the home country and host country?
4. How does the technological development impact aging in China? Specifically, how does the advancement in medical sciences affect aging in China? How does the development in artificial intelligence and the robot industry affect old age care in China?
5. In sum, how do the above new issues affect the population issue in China, and what policies should we recommend to the government?

In addition to the above urgent questions, we also welcome papers that discuss more general issues of population in China, such as topics on the historical, present and future demographic courses that impact China and beyond for this special issue.

The issue selected 15 papers, with seven in English and eight in Chinese, which will be published in two volumes.

This is the second volume of the special issue with the eight papers in Chinese.

The first article, “The Effect of Two-child Policy on China’s Fertility by Song Jian discusses the effect of lifetime fertility and period fertility of Chinese women. She indicated the two-child policy has significant influence on the birth of the second child, but the influence has not been strong enough to revitalize the period fertility level.

In “The Mechanism of Gender Imbalance and Governance in China: Perspectives of Population Transition and Policy Adjustment” Bo Yang and Shuzhuo Li found that fertility policy adjustments improve the governance on gender imbalance; aging policy adjustments lead the governance on gender imbalance to social governance; combined with urbanization policies, the governance on gender imbalance could develop a comprehensive policy system for both rural and urban communities.

Wang Jianping and Ye Jintao discuss the growth, characteristics and patterns of International Emigrants from China. They review the migration policies in leading immigrants receiving countries, discuss the scale, the flow of movements, the composition, as well as the characteristic of emigrants from China.

Does family migration promote the migrants’ subjective willingness of community integration? Wu Fan, and Zhou Miao indicated that migrants’ subjective willingness of community integration still stays at a low level. However, family migration has a more significant impact on migrants’ subjective willingness of community integration due to emotional support effect.

Li Jingbo, Gao Yuan and Yuan Xin’s paper “The Research on the Migrant Population’s Vocational Choice -Based on the Perspective of Segmentation for the Household Registration System” pointed out that the vocational choice of urban-to-urban migrants is better than rural-to- urban migrants and inhabitant migrants after divided migrants into rural-to- urban migrants, inhabitant migrants and urban-to-urban migrants. An invisible threshold in the labour market seems restrict the vocational choice of rural-to- urban migrants.

In “Current Situation and Challenges of Health Poverty Alleviation of Provinces along the Silk Road: Findings from survey in Shaanxi, Gansu and Xinjiang.” Weui Yan, Yan Qi and Gao Yingxia, based on the special survey data of 2017-2018, analyze the health status, multi-dimensional poverty and the implementation of health poverty alleviation policies in Shaanxi, Gansu and Xinjiang. They indicated that multidimensional poverty generally exists in rural households in the three provinces. Health statuses of the poverty-stricken households were poor, and the incidence of multidimensional poverty is high. The health infrastructure in Xinjiang is the worst.

The seventh article, “A Study on the total Population and Structure of the Elderly Who Can't take Care for themselves in China.”Wang Guangzhou uses the data of 1% population census and CFPS 2010 of Peking University to indicated that in 2015, the total number of elderly people aged 60 and above who can not take care of themselves was 5.76 million, 3.05 million elderly people without spouses living independently in China, the elderly people with one surviving child who can not take care of themselves exceed 1 million.

Finally, we have a paper discuss Taiwan's population decline in the urbanization process. Chun-Ya Liu, De-Piao Tang and Chih-Sung Teng explore why some urban areas have developed better over time with population gradually increasing, while others’ populations have been shrinking. What are the key determinants of urban development? They pointed out that it is mainly related to "rural decline.” A total of 6 among 23 counties are shrinking, and that 60 localities present a "significant population decline" Furthermore, socioeconomic factors like the growth rate of the aging population, the successful transformation of the industry, and the convenience of transportation are the mains factors impact urban development.