在人口老龄化程度不断加深的背景下，本文提出并建立人口经济模型，从个体和厂商的微观决策出发，一般均衡时的稳态资本存量恰好符合黄金定律，本文建立的理论模型是对经济增长理论的发展和创新。在建立基准的人口经济模型后，将人力资本引入该模型，并研究人力资本的形成机制。个体除了需要进行终生消费的优化配置，还需进行教育年限的选择，即需要同时完成消费与储蓄决策和教育与工作决策。本文从“出生侧”和“死亡侧”分析人口结构转变的内在机制，指出新生人口增长率和预期寿命两个参数是影响人口结构的关键因素，从而进一步分析老龄化和人口政策对人力资本积累和经济增长（人均产出增长的视角）的影响。研究发现，新生人口增长率下降和预期寿命延长都会造成人口老龄化，但对人力资本积累的影响却不相同。具体的，新生人口增长率下降使得个体选择更长的受教育年限，人力资本水平上升；预期寿命延长不影响个体的最优受教育年限，不影响人力资本积累。与此同时，控制新生人口增长速度从长期来看，无论是对人均产出还是对人均消费，都能发挥积极的作用，而预期寿命的延长都以负面影响为主。为了缓解老龄化对经济体造成的负面影响，调节人口结构，政府实施了全面二孩政策，并即将出台延迟退休政策。研究发现，鼓励生育政策能够降低老龄化程度，但从长期来看，不利于人力资本积累，同时无论是对人均产出还是对人均消费，都以负面影响为主。而延迟退休政策从长期来看，有利于人力资本积累，同时无论是对人均产出还是对人均消费，都能发挥积极的作用。因此应当审慎运用人口和就业政策应对人口老龄化问题。增长核算的结果表明，目前我国的经济增长仍属于物质资本推动型。分时期增长核算的结果表明，近年来人力资本对经济增长的贡献有所下降，一方面是由于物质资本投入的高速增长稀释了人力资本的贡献，另一方面从人力资本的分解构成看，主要是由于劳动力数量增速的大幅下降，而劳动力质量的提升在某种意义上迟滞了人力资本总量增速的下滑。目前，我国已经进入老龄化社会，劳动力绝对数量逐渐下降，而物质资本的投入不可能长期维持高增长。未来要保持经济的长期高质量发展，必须要将经济增长模式从资本密集型和劳动力密集型升级为智力密集型。为此，要充分重视劳动力质量的提升，加大人力资本投入和产业引导力度，实现经济转型。

Under the background of deepening population aging, this dissertation proposes and establishes a population-economic model. Starting from the micro-decisions of individuals and manufacturers, the steady-state capital stock in the general equilibrium exactly coincides with the golden rule. The theoretical model established in this dissertation is development and innovation for economic growth theory. After establishing a benchmark population-economic model, human capital is introduced into the model, and the formation mechanism of human capital is studied. In addition to the need to optimize the allocation of life-long consumption, individuals need to choose the number of years of education, that is, they need to make consumption-saving decision and education-work decision at the same time. This dissertation analyzes the internal mechanism of population structure change from “birth side” and “death side”, and points out the growth rate of newborn population and life expectancy are the key factors affecting the population structure, so as to further analyze the impact of aging and population policies on human capital accumulation and economic growth.This dissertation finds that the decline in the growth rate of new-born population and the extension of life expectancy will result in aging, but the impact on human capital accumulation is not the same. Specifically, the declining growth rate of the newborn population allows individuals to choose a longer period of education and human capital levels. Life expectancy extension does not affect the individual optimal years of education and does not affect the accumulation of human capital. At the same time, controlling the growth rate of the new-born population will play a positive role in terms of per capita output and per capita consumption in the long-term, and the extension of life expectancy will mainly be negative.In order to alleviate the negative impact of aging on the economy and regulate the population structure, the government implemented two-child policy and will soon introduce postponed-retirement policy. The study finds that encouraging childbearing policies can reduce the degree of aging, but in the long term, it is not conducive to the accumulation of human capital, per capita output and the per capita consumption. The postponed-retirement policy, in the long term, is conducive to the accumulation of human capital, and it can play an active role in both per capita output and per capita consumption. Therefore, we should prudently apply population and employment policies to deal with population aging.The growth accounting shows that China's economic growth is still driven by physical capital. The results of the time-phased growth accounting show that the contribution of human capital to economic growth has declined in recent years, partly because the rapid growth of physical capital investment has diluted the contribution of human capital. On the other hand, from the perspective of the decomposition of human capital, it is due to the sharp decline in the growth of the labor force, and the increase in the quality of the labor force has delayed the decline in the growth of the total amount of human capital.At present, China has entered an aging society. The absolute number of laborers has gradually declined and the investment of physical capital cannot maintain high growth over the long term. In order to maintain the long-term high-quality economic development in the future, we must upgrade the economic growth model from capital-intensive and labor-intensive to intelligence-intensive. To this end, we must pay full attention to the improvement of the quality of labor, increase human capital investment and industrial guidance and achieve economic transformation.