Based On The BP Neural Network To Study The Impact Of The Two-child Policy On The Population Structure Of Our Country

Mainly through establishing the recursive model,interpolation function model,regression analysis model and BP neural network model,This article predicts the future population structure of China under the comprehensive two-child policy at first,and then studies the influence of future population structure on economic development before and after the policy.At last,The relationship is simulated between the population structure and economic development in Shandong Province by using the BP neural network model and algorithm.On the one hand,this paper makes the curve function fitting to get the population of2016 under no open two-child policy according to the total population of China in1996-2015.Then it gets the annual mortality since 2016 by Logistic model and curve fitting using MATLAB tools and least squares algorithm.Suppose that the birth rate is1.2916 percent,and then predicts the future total population of more than ten years in our Country every year using the differential equation and recursive model.On the other hand,this text analysies and summarizes the data of China's population structure(0-14 years old,15-65 years old and over 65 years old),and then selects two economic indicators,namely per capita GDP and household consumption level.Then the relationship between the proportion of each age group and the two economic development indexes is obtained through the BP neural network model and curve fitting.And then combined with the forecast data of China's future population from 2030 to 2050,the impact of demographic changes on GDP per capita and consumption level of residents is analyzed in the same way.Through analysis and comparison,it can be seen that the two-child policy in our Country is beneficial for the economic development in the short term.But the policy cann't last too long,or there are too many people of 0 to 14 years old age in the future.In order to avoiding the other social and economic problems caused by overpopulation,the increase of newbornit must be inhibited around 2045.Finally,It is simulated the database combined the data of population structure and economic growth in Shandong Province through the BP network model and algorithm.The predict effect is better.