Research On The Influencing Factors Of China’s Population Growth Based On High-dimensional Variable Selection

In recent years,China’s birth rate has hit a new low year after year,with the net growth of population at the end of 2022 is only-0.85 million,the problem of population growth had become very serious,what factors hinder China’s population growth?It had become the focus of national and social attention.There are many factors affecting population growth,and it is easier to collect data in the information age,which makes the data of population growth factors present a high-dimensional and small sample characteristics.At present,there are few literatures that use high-dimensional variable selection method to explore the factors affecting population growth,their variable se-lection is not comprehensive enough,and the variable selection process and method are single.Based on this,in this paper,firstly,two variable selection processes are used to screen 92 factors that affecting population growth at the political,economic,cultural,social,ecological and population levels by using similarity analysis method,gray cor-relation analysis method,random forest method,regularization method and integration method;Secondly,the variables selected under each method are fed into mainstream machine learning models KNN,RF,SVR and MLP,and the variable selection effect of each method is comprehensively evaluated according to the model average prediction performance indicators of MAE,MSE,RMSE,R~2 and MAPE,and the optimal variable selection process and methods are obtained,forming several optimal variable selection schemes;Finally,using the selected variables under each variable selection scheme to establish multiple linear and nonlinear models,and select the model with better perfor-mance for prediction analysis.The empirical results show that:(1)the variable selec-tion effect of the second variable selection process is best;(2)The variable selection effect of replacement importance,and distance correlation coefficient are better;(3)The employment problem is the core factor for the decline of China’s birth rate.