二孩政策对产妇分娩数时间序列的影响

Influence of the two-child policy on the time series of the number of births

目的采用带干预的ARMAX模型剖析“开放二孩政策”对产妇分娩数的影响及其作用机制,以期为计划生育相关政策调整提供参考依据。方法分析2013年1月至2019年12月产妇分娩数时间序列变化趋势,分别构建无干预、脉冲干预及阶梯干预的ARMAX模型,并从拟合优度、残差正态白噪声检验、模型参数显著性检验等方面,评价模型对数据的建模解释能力。结果脉冲干预ARMA(1,0)-X模型对产妇分娩数的建模解释能力显著优于无干预、阶梯干预的ARMAX模型,自回归参数、线性趋势参数以及干预部分参数均有统计学意义,且通过残差正态白噪声检验。结论脉冲干预ARMAX模型能很好地解释分娩数变化趋势;干预分析结果表明,“开放二孩政策”显著激发了群体生育意愿,但激发作用短暂存在,快速衰减,这与政策长久刺激的预期尚存一定差距。

Objective To analyze the influence of the"open two-child policy"on the number of births and its mechanism by using ARMAX model with intervention,so as to provide reference for the adjustment of family planning policies.Methods The variation trend of time series of births from January 2013 to December 2019 was analyzed,and the ARMAX models without intervention,pulse intervention and ladder intervention were constructed respectively.Moreover,the ability of the model to model and interpret the data was evaluated from the aspects of goodness of fit,residual normal white noise test and model parameter significance test.Results The modeling and interpreting ability of pulse intervention ARMA(1,0)-X model was better than that of ARMAX model without intervention and step intervention,and the autoregression parameters,linear trend parameters and part of the intervention parameters were statistically significant,and passed the residual normal white noise test.Conclusion The pulse intervention ARMAX model can well explain the variation trend of the number of births.The results of intervention analysis showed that the"open two-child policy"significantly stimulates the population′s fertility desire,but the stimulation effect exists for a short time and declines rapidly,which still has a certain gap with the expectation of long-term policy stimulation.