Positioning The Middle-income And Measur-ing The Middle-income Population Based On Lorenz Curve

Since The Eighteeth National Congress of the CPS,"China Dream" became the hott est topic after the "harmonious society "."Two hundred targets" is the core objective of C hina dream, which is the full realisation of a well-off society and rejuvenation of the chin ese nation.No matter what objective should we achieve,we must ensure that social inco me distribution is equirtable and resonable.It can be shown that the proportion of middle-income group is increase.This thesis is mainly focus on "middle-income groups".It can be studied from the following aspects.(1) The definition of "Middle-income groups":This definition can be obtained from different angles, such as the urban-rural structure、income occupational structure and dynamic angle comprehensive analysis. For Middle-income groups,Income not only can be meet the food and clothing but also has the feature of steadiness. This group can change their situation through the dynamic group that relying on their ability. It is also the highly coordinate for the social development.(2)Lorenz Model Construction and Proof:In this thesis, the necessary and sufficient conditions L(0)=0、L(1)=1、L’(p)≥0.、L"(p)≥0for the Lorenz curve L(p) is regarded as a starting point. The Seven models such asL1(p)、L2(p)、 L3(p)、L4(p)、L5(p)、L6(p)and L7(p),can be constructed by meeting the necessary and sufficient conditions, and three models such as L1,(p)、L2(p)、L3(p),can be testified.(3)The fitting parameters and merit of Lorenz Model. In the condition of three criteria of model fitting precision, through analysising the fitting parameters of income distribution data. The optional Model L4(p) can be obtained.(4) Two methods and improvement of "Middle-income groups" measurement. In order to make the empirical analysis, the specific assumptions and improvements are made in the condition of the definition of "Income Space Law" and "Population Space Law" are known.(5)The Empirical Analysis and Location of middle-income groups. The empirical analysis includes two parts:First part is longitudinal analysis, which is referring to the proportion of middle-income in the same area of two consecutive years. Second part is cross-sectional analysis in the different regions of the same year.Through the studies above, we can make conclusion that the analysis results of "Population Space Law" and "Income Space Law" are basically accordance. It is can be reflected through the proportion of Middle-income population of these two models comparation show that the proportions of middle-income population of these tw o models tend to decrease. Longitudinal comparation show that the proportion of middle-income population of theses two models in B is significantly higher than A.