关键词: 中等收入群体, 标准与规模, 核密度估计

Abstract: With the continuous improvement of China's economic, China has entered the ranks of high-income countries. The expansion of the middle-income group has an important influence on middle-income countries across “Middle Income Trap”, although the definition of the middle-income group and measurement has many achievements, but there still has controversy. In this paper, we compared with the literature’s definition of middle income group standards and measurement basis, and found that per capita disposable income of households as a standard in defining the Chinese middle-income group can adapt to the reality of the huge differences between the areas of our country. Based on Chinese family tracking survey (CFPS) data of 2010, 2012, 2014, this paper using the method of kernel density estimation to fit China's households per capita disposable income distribution curve, calculate the proportion of the medium income group in 2010, 2012 and 2014, the results can be used for our country to improve the distribution pattern of income and expanding middle-income groups and provide a theoretical basis for the formulation of relevant policies.

Key words: Middle-income Group, Standard and Scale, Kernel Density Estimation