The Simulation Kesearch Of Population Strategy In China’s Future By Leslie Model

Population is a significant problem with the human social development. China has the most population during the developing countries in the world. Only if we solve the population problem can we deal with the problems of China’s economic and social development. China’s fertility policy as a tool to control each indicator of population with the direct method, has the relation with China’s population, resources, environment’s coordinated development.The establishment of it plays a decisive role in economic and social development. So population prediction and population policy formulation are always the research topics,which academia and national policy makers pay attention to.In the21st century, the population, economy and environment situation of China have changed greatly.There are some new phenomenon,such as the birth sex ratio serious imbalance,aging population increasing seriously,the labour market facing shortage and so on.They influence on china’s further economic and social development which urgently needed to be solved. In the face of the new study environment,what’s the china’s fertility policy to follow? The chinese academic community have different perspectives. If china continues to implement the current population policy,can it adapt to the new development situation? how the future population size and age structure to develop? What effect can it make on the the social various aspects field? whether need to adjust the current population policy? If need to adjust, it is the question that how to adjust? These are the problems which urgently need to resolve in the new study environment. This paper is based on Leslie model to solving these problems as the foothold research, and has important theoretical significance and practical value. It is the subject that have boththeoretical and practical significance.This paper first summarizes our country’s population policy and analyzes the current population policy’s merits and demerits. Then it review the research on population forecast model and there is a comparative analysis of the main population forecast models:Logistic model, Regression equation model,BP neural network model and the Leslie model. After parameter setting, this paper set five different population policy scheme,using specific Leslie model to predict the future of status of population development in fifty years. There is a comparative analysis of the advantages and disadvantages of each method, and then select the best one, it is now immediately relaxing population policy,it means average2.1children a woman can give birth to during the whole life.The paper includes6parts arranged as follows:Chapter1is the introduction section,. which expounds research background, research purpose and meaning, the framework of the passage, the innovations of the article and deficiencies.Chapter2is China’s population policy and its research review. This chapter summarizes our country’s population policy,analyzes the current population policy’s merits and demerits and combinges population policy research of the domestic scholars.Chapter3presents research review of population prediction model and the introduction of the model that this paper selects. This chapter first review the research on population forecast model.After that there is a comparative analysis of the three main population forecast models:Logistic model, Regression equation model and BP neural network model. Finally, it introduce the Leslie model that selects and its advantages of population prediction.Chapter4presents the variable selection, parameter setting and software realization of Leslie model. Based on the first two chapters, this chapter place a great emphasis on Leslie matrix model variable selection and determination of parameters:age-specific fertility rate, age-specific mortality and birth population sex ratio. The first is to determine the age-specific fertility rate:fitting standardized age-specific fertility rate data by logarithmic normal distribution and weibull distribution, through contrasting the result to determine procreation pattern.The second is to determine the age-specific mortality: Use the weighted average of5 years’age-specific mortality data as the mortality of predicted value. The third is to determine birth population sex ratio:the change trend of birth population sex ratio has no specific rule,so this paper uses the method combining GM (1,1) model and qualitative analysis to forecast. Finally this chapter presents the advantage of combination of matlab software and Leslie model and explain the relevant program code.Chapter5is forecast and analysis for china’future based on the different population strategy simulation. This chapter set five different population policy scheme and the different will be reflected on the total fertility rate. predict the future of status of population development in fifty years. There is a comparative analysis of the advantages and disadvantages of each method, and then select the best one, it is now immediately relaxing population policy,it means average2.1children a woman can give birth to during the whole life.Chapter6is conclusions and policy recommendations. it summaries the whole paper and puts forward some policy recommendations according the best population policy the paper select. Finally this paper presents the prospect of research.The innovations of this paper are as follows:First, Leslie model will be introduced into the population prediction using Matlab software platform. Different population policy scheme are compared and analyzed, and finally select the best feasibility scheme.Second, determination of Leslie model parameters is in detail. The paper fitstandardized age-specific fertility rate data by logarithmic normal distribution and weibull distribution, through contrasting the result to determine procreation pattern.and uses the method combining GM (1,1) model and qualitative analysis to forecast birth population sex ratio,and according to the different population policy scheme give different predicted sex ratio at birth.The deficiencies of this article are as follows:First, the paper use the weighted average of5years’age-specific mortality data as the mortality of predicted value,but there need further research on more accurate method for the determination of specific weights.Second, In the different population policy scheme comparison, the author just from two aspects that the population distribution and structure to analysis.There need more comprehensive and accurate method to measure valuation.