Abstract：Objecrive 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.
王倩，张小建. 二孩政策对产妇分娩数时间序列的影响[J]. 中国医院统计, 2021, 28(2): 168-171.
Wang Qian, Zhang Xiaojian.. Influence of the two-child policy on the time series of the number of births.. journal1, 2021, 28(2): 168-171.
［1］蒋雪婕，徐靖．图解十八届五中全会公报［J］．世纪行，2015(10)：2．
［2］段美枝．“全面二孩” 政策目标下生育保障制度改革研究［J］．卫生经济研究，2018(4)：20-22．
［3］茅倬彦，徐继红．构建鼓励按政策生育的制度环境：中国人口学会2017年年会分论坛［J］．中国计划生育学杂志，2017，25(8)：575-576．
［4］陈瑛瑛，褚伯良，陈云燕. 全面放开“二孩”政策前后湖州市妇幼保健院住院孕产妇分娩情况分析［J］. 中国医院统计，2019，26(2)：115-118.
［5］劳雅红，祝志娟，赵叶芳，等. “全面二孩”政策下绍兴地区育龄妇女生育意愿及影响因素分析［J］. 中国医院统计，2018，25(3)：192-194.
［6］王红，聂晶，尚佳，等．全面二孩政策下四川省生育状况及意愿现状调查［J］．中国妇幼健康研究，2018，29(12)：1534-1539．
［7］刘梅讯，孙天敏．实施全面二胎政策对医疗资源的需求及其策略分析［J］．中国卫生产业，2017，14(5)：187-189．
［8］杨晓畅，蒲川．“全面二孩”政策下重庆市育龄妇女二孩生育意愿及影响因素分析［J］．中国卫生事业管理，2018，35(10)：786-789．
［9］魏武雄．时间序列分析单变量和多变量方法［M］．北京：中国人民大学出版社，2009．
［10］LJUNG G M, BOX G E P. On a measure of lack of fit in time series models［J］. Biometrika, 1978, 65(2): 297-303.
