In the process of building a modern country, China is witnessing major changes unfolding in our world, something unseen in a century. China is also facing challenges such as rapid population ageing, negative population growth and a decline in labor force that would largely impact its socioeconomic development and comprehensive strength. Based on a renewed understanding of the population development and its relationship with socioeconomic development, this paper discusses the state of population development needed to enhance the country's economic strength. It also proposes the scope and direction of China's longterm population development in the future, emphasizing the central and fundamental position of population size. To be specific, the desired population size should be between 0.9 and 1.2 billion by the end of this century. Actively changing the longterm trajectory of population development, raising the fertility rate close to the replacement level and keeping the population size between 0.9 and 1.2 billion would also improve the population structure, quality and spatial distribution, strengthening the economy.

 After 40 years of economic reform, China's economy has achieved a miracle of sustained and rapid growth. For an industrialized society, public services can narrow the income gap between the rich and the poor, coordinate unbalanced development, maintain social equity and justice, and improve people's life. How to achieve a balance between sustained economic growth and the improvement of the quality and level of public services? Can public services promote economic development? What is the mechanism? Based on provincial panel data from 1994 when China's tax reform started, this research uses econometric panel analysis methods to examine the role of public services in economic growth. Specifically, we treat the public services as the core variables in the analytical model and explore how they affect economic growth after controlling for population structure, population aggregation and other factors. Empirical evidence shows that in the era of slow population growth, population aging, and urban population agglomeration, the improvement of public services has a significant role in promoting economic growth and is an important source of economic development.

The development of regional economy depends on the regional central cities and the accumulation of human capital. Therefore ,the construction of the central city becomes the growth pole of regional development. It plays a significant role in regional economic and social development,and human capital accumulation is the key to realize its functions. How does central city enable the human capital accumulation? In this paper,we establish spatial econometric models to explore the effect of the central city on human capital accumulation,from the aspects of economy,industry,education,employment and medical service. It is found that the industrial development,public expenditure,education and medical care have significant impacts on regional human capital accumulation. The impacts of central cities on regional human capital accumulation shows different mechanisms,some are accumulation, while others are spillover. Therefore, development strategies of central cities should be formulated to take into account both their own economic development and the interaction among cities,ultimately achieving common development.