Analysis And Forecasting Of Two-Birth Fertility Rate In China Using Functional Data Model

It is very important to forecast fertility rate in order to formulate the national population policy.How to accurately quantify the trend of fertility and formulate the future population plan is the key point under current situation.This paper aims to actively respond to national policy and guideline,and explore the impact of the two-birth policy on the current fertility rate under this new condition.Functional data analysis and change-point analysis are less applied in the research field of fertility in China.Based on functional data model,the two-birth fertility rate by women of childbearing age is forecasted in different regions including whole country,cities,towns and villages.Meanwhile,in order to explore the influence of policy on the fertility rate of two-birth and the change trend,the completeness analysis and change-point analysis are adopted to evaluate and investigate the previous fertility level of two-birth in China.The results show that the functional data model can take advantage of the data reasonably,provide reliable prediction results and depict the trend of future when the fertility rate is relatively in a stable state.The city's two-birth fertility rate is predicted to enter the growth period in the future,but from the prediction curve of the national two-birth fertility rate,the effect of universal two-birth policy does not seem to cause big increase in fertility rate and strong rebound in population growth in a short-term period,and monitoring could continue in the future on the basis of more fertility data.For completeness analysis and change-point analysis,they can better interpret the change of historical data.The completeness analysis reveals that late childbirth is the common phenomenon in China at present,and release of the two-birth policy has played a certain role in promoting the fertility intention of women of childbearing age.The change-point analysis proves that the policy reform mainly affects the two-birth fertility rate in cities and towns,while the villages are not affected by the single two-birth and universal two-birth policies,and the change is relatively stable.Reasonable use of functional data analysis and change-point analysis to explore the characteristic and trend of fertility rates could be one of the future research directions.