中国人口平均预期寿命预测及其面临的问题研究

Research on the Prediction and Its Problems of Life Expectancy of Chinese Population

以经典的Lee-Carter死亡率模型为工具,采用中国1994—2019年死亡数据,构建Lee-Carter死亡率模型,研究中国人口平均预期寿命预测问题。研究表明:虽然中国死亡数据资源越来越丰富,但不同来源数据质量差距和冲突依然比较明显。随着死亡水平的下降,1994年以来1‰人口变动抽样调查死亡数据面临的质量问题比较突出。从Lee-Carter死亡率模型拟合效果来看,模型拟合年龄别死亡率平均相对误差较小的年龄组为40—84岁,0岁组拟合效果较差,而0岁人口死亡率的数据质量在模型拟合、平均预期寿命推算和预测过程中非常重要。由于年龄别死亡率数据误差相抵的原因,对出生人口平均预期寿命的推算误差明显下降。在平均预期寿命研究结果的应用过程中,对不同年龄人口平均预期寿命的相对误差和绝对误差需要区别对待。考虑到中国历史数据的质量问题,在建模过程中需要防止模型对基础数据的过度拟合问题。由于死亡人口重报,特别是多报的可能性很小,现有数据和模型对人口平均预期寿命的估计或预测肯定是一个高估。

By means of the classical Lee-Carter mortality model and Chinese mortality data from 1994 to 2019,this paper constructs the Lee-Carter mortality model to study the prediction of Chinese life expectancy at birth.The research shows that although Chinese mortality data sources are get rich step by step,the gap and conflict of data quality from different sources are still obvious.With the decline of mortality level,the quality problem of mortality data in 1‰population change sampling survey since 1994 is more prominent.From the fitting effect of Lee-Carter mortality model,the age group with small average relative error in fitting age-specific mortality is 40-84 years old,and the fitting effect of 0-year-old group is poor.The data quality of 0-year-old population mortality is very important in the process of model fitting,calculation and prediction of life expectancy at birth.Due to the error offset of age-specific mortality data,the estimation error of life expectancy at birth decreased significantly.In the application of the research results of life expectancy at birth,the relative error and absolute error of life expectancy at birth of population for different ages need to be treated differently.Considering the quality of Chinese historical data,it is necessary to prevent the model from over fitting in the modeling process.Since there is little possibility of re-reporting,especially over reporting,the existing data and models must overestimate or over prediction the life expectancy at birth.