基于结构方程模型的中国县域人口老龄化影响机制

Influencing mechanism of regional ageing in China based on the Structural Equation Model

利用2000年和2010年分县人口普查数据,分析中国县域人口老龄化的空间格局及变化,采用结构方程模型拟合人口老龄化影响因子之间的路径关系,探讨中国县域人口老龄化的影响机制。结果表明:内蒙古包头至云南腾冲是中国县域人口老龄化较为清晰的空间分界线,其东南部老龄化高值县区连片集中,低值县区夹杂其间;西北全域老龄化率普遍较低,仅在北缘横亘一条中值县区连绵带。结构方程模型的拟合结果很好地解释了中国县域人口老龄化空间差异的影响机制。迁移率、预期寿命和生育率是人口老龄化进程的内生因素,其中,预期寿命对县域人口老龄化有正向效应,迁移率和生育率则对县域人口老龄化有负向效应。社会经济、家庭状况和自然环境等因素是人口老龄化进程的外生因素,对中国县域人口老龄化有显著的直接和间接效应。收入增加、社会发展、居住条件改善以及环境舒适性提高等推高县域人口老龄化水平,城镇化水平提高则降低县域人口老龄化水平。

Since the 1970 s,great progress has been made in research on the spatio-temporal pattern of population ageing at multiple spatial scales by both domestic and foreign scholars.However,the analysis of the process mechanism of regional ageing is still insufficient.Based on the county-scale data in 2000 and 2010 censuses,the spatio-temporal pattern of population ageing is statistically analyzed.Moreover,the Structural Equation Model(or SEM)is developed to explore the path relationship between various variables.Consequently,the influencing mechanism of regional ageing process is thoroughly revealed.The main results are as follows.Firstly,the line from Baotou City of Inner Mongolia autonomous region to Tengchong County of Yunnan province(or BT Line)is a geographical demarcation of regional ageing disparities in China.Southeast of the BT Line witnesses contiguous areas of higher ageing counties which interspersed with lower ageing counties,whereas northwest of the BT Line is a continuous area of lower ageing counties with just one middle-level ageing belt located in the north margin.Secondly,the fitting results of SEM interpret the influencing mechanism of regional ageing disparities in China.Thirdly,life expectancy,fertility and migration are three endogenous factors of regional ageing process.Thereinto,life expectancy has significantly positive effect,while fertility and migration have significantly negative effects on regional ageing.Lastly,geographical environment has significant direct and indirect effects on regional ageing in China.In general,the income increase,social progress,and the improvement of living conditions and natural environmental quality would enhance regional ageing level,otherwise the improvement of urbanization level would decrease regional ageing level.