人口老龄化、公共人力资本投资与 经济增长*

本文利用内生化老龄化的世代交叠模型，探讨了老龄化社会中为了促进经济增长可选择的公共人力资本投资的最优相对规模和结构。本文研究表明，公共人力资本投资相对规模（即占GDP比例）和公共健康支出占比（即占公共人力资本投资比例）均与经济增长呈倒U型关系，且最优值通过老龄化对经济增长的作用表现出来。即当老龄化对经济增长有促进（抑制）作用时，政府促进经济增长的政策是提高（降低）人力资本投资相对规模和公共健康支出占比。基于中国省级面板数据的实证研究发现，老龄化不利于经济增长，公共人力资本投资相对规模及公共健康支出占比偏大，均处在倒U型曲线的下降阶段，分别通过挤出对经济增长更具促进作用的私人投资、公共物质资本投资和公共教育支出而不利于经济增长。本文的政策含义是，政府需提高公共教育支出占比，引导和鼓励更有效率的社会私人资本进行人力资本投资，以逐步降低公共人力资本投资的相对规模。当前公共物质资本投资则需继续加强。

POPULATION AGING,PUBLIC HUMAN CAPITAL INVESTMENT AND ECONOMIC GROWTH

This paper analyzes the growth oriented optimal structure and relative scale of public human capital investment in an aging society by establishing an extended overlapping generation model which endogenizes population aging. The theoretical analyses indicate that there are inverse U curve relationships between the relative scale and structure of public human capital investment and economic growth. The optimal scale and structure of public human capital investment are reflected by the correlation of aging population and economic growth. Specifically, if aging has positive (negative) effects on economic growth, the growth oriented policy is to increase (decrease) public human capital investment to GDP ratio and public health investment to public human capital investment ratio. The empirical studies based on the panel data of Chinese provinces suggest that population aging has negative effects on economic growth. The scale of the public human capital investment and the proportion of public human health investment become so large, lying in the decline stage of inverse U curve, that they depress the economic growth through crowded out effects. The policy implications of this paper are as follows: the government should increase the public education investment to public human capital investment ratio and encourage more efficient social private capital to invest in human capital accumulation so as to decrease the relative scale of public human capital investment; the scale of public physical investment should be reinforced at present.