我国人口的社会结构失衡:理论机制与经验事实

随着生育率水平的持续下降,我国不仅面临人口数量增长的困境,而且也发生了严重的人口社会结构失衡.文章基于教育资源稀释理论,从理论和经验两个方面研究了教育与生育率之间的相互作用以及由此所决定的人口发展规律,从而论证了人口社会结构失衡现象及其形成机制.研究表明:(1)教育与生育率之间的相互作用机制,一方面可以使生育率水平持续上升,导致人口发展进入高生育陷阱,另一方面也能够使生育率水平不断下降,让人口发展滑入低生育陷阱,由此形成了人口发展的"Z"形变化规律,即在中等教育水平上教育与生育率之间显著负相关,而在较高和较低的教育水平上两者并无明显关联;(2)由于我国的教育发展存在明显的城乡差距、地区差距和民族差距,那么在"Z"形人口发展规律的影响下,所有居民必然会逐步分化为两类,分别向生育率的高低两端集聚,从而就产生了人口的城乡结构、地区结构、民族结构和素质结构的失衡.进一步地,文章基于全国人口普查县级数据,使用工具变量法和Hausman-Taylor估计方法,验证了这种"Z"形人口发展规律及其所决定的人口社会结构失衡.文章不仅可以丰富当前的人口结构研究,而且对我国的人口和教育改革具有重要的启示.

Social Structure Imbalance of Chinese Population:Theoretical Mechanism and Empirical Analysis

With constant reduction in fertility rate, China is not only faced with the plight of population growth, but also has a serious imbalance in the social structure of population.Based on educational resource dilution theory, this paper theoretically and empirically analyzes the interaction mechanism between education and fertility rate & the law of population development, and finally demonstrates the imbalance of social structure of population and its forming mechanism.It comes to the conclusions as follows: firstly, on the one hand, the interaction mechanism between education and fertility rate can lead to the gradual rise in fertility rate and thereby make population development enter into a high fertility trap;on the other hand, it may cause fertility rate continue to decline and fall into the trap of low fertility, finally forming the "Z" pattern of population development, namely at middle education level education is significantly negatively related with fertility rate, but at higher or lower education levels there is no significant correlation between education and fertility;secondly, owing to obvious urban-rural, regional and ethnic differences in education development, affected by the "Z" law of population development, all residents are bound to gradually be divided into two categories, the fertility rate of residents will differentiate high and low ends, and this development of population will lead to the imbalance of the population of urban and rural structure, regional structure, national structure and quality structure.Furthermore, based on nationwide census county-level data, this paper uses instrumental variables method and Hausman-Taylor estimation method to examine the "Z" law of population development and resulting imbalance of population social structure.It not only enriches current population structure research, but also has important implications for the reform of population and education in China.