With the growth of internet usage among older people, concerns about “older adults' internet addiction” frequently appear in media and research. To achieve a comprehensive understanding of “older adults' internet addiction”, this study discusses the concepts, phenomena, and impacts of “internet addiction”. “Internet addiction” is characterized by three features, including “excessive use”, “damage to primary activities and social functions”, and “persistent and prolonged states”. Existing discussions and studies mainly focus on the single dimension of “excessive use”, exaggerating the issue of “older adults' internet addiction”. Data from the “Survey on the Digital Divide and Integration of the Older Adults in China” show a low proportion of older people who are addicted to the Internet. Currently, the main challenge in the internet lives of older adults is how to deal with the “digital divide”. To enhance the internet accessibility and proficiency of older adults, we suggest upgrading the intelligent device hardware, software, and functions for their convenience and providing guidance on smartphone use for older people. This will help older adults benefit from the development dividends in the internet era.

The key to accurately assessing China's fertility level lies in high-quality data. The 7th population census has obtained data of very high quality mainly due to the newly added ID number registration and application of information technology, providing a good opportunity for reassessing China's fertility level. This study shows that the total fertility rate (TFR) of China maintained above 1.6 from 2006 to 2017, exceeded 1.7 in most of the years, but dropped sharply from 2017 to 2020. The TFR was fluctuating considerably, ranging from a low of just 1.3 in 2020 to a high of 1.89 in 2012 and 1.88 in 2017, with a 15-year average of 1.7. Fertility preferences, fertility policy adjustments, and COVID-19 had marked influence on fertility level. The average number of children ever born suggests that there is still potential for improvements in China's fertility level, and the key measure is to fully eliminate the emerging fertility inhibiting factors and build a fertility/family-friendly society to tap this potential.

In order to establish a population equilibrium society, some problems should be addressed properly, such as population and environment equilibrium, population structure equilibrium and equilibrium between population and socioeconomic development. Natural environment can be only improved slowly; adjustment of population structure is the best choice to better the equilibrium between population, environment and social economy. Severe equilibrium problems that China currently faces are concerning sex ratio at birth, population aging and age structure, education and human capital structure, regional population distribution, urban and rural structure of population, and population class structure.

Based on ArcGIS as analytical tools and the 2000 census data,this research is carried out in county units. The result indicates that among principal function areas,key development zones have the highest population size while optimized key development zones the highest population density. Compared with limited development zones of lowest population quality,optimized development zones show highest population quality. As for age structure,optimized development zones reveal highest proportion of labor population. Further analysis demostrates that population migration does not follow the planning of principal function Areas. Current technical and cultural development may still not meet the requirement of principal function Areas planning. A large number of labors assemble in optimized development zones,which deviates from principal function Areas planning. In order to achieve regional population equilibrium,proper population and industrial policy should be implemented in different principal function Areas with consideration of regional advantadges. In addition,population policy should coordinate with other public policy.