ABSTRACT
The Chinese academic community has yet to form a clear consensus on how to define the concept of a middle-income group, and there is a great deal of debate on precisely how it should be demarcated. Linking the classification concept of the middle-income group to the middle class is necessary if the middle-income group is to connote a social group. The traditional occupation-oriented middle-class concept emerged with the great changes and awakening in the social structure of developed countries in Europe and the USA following World War II. The proportion of middle class defined by income indicators began to be an important indicator for observing the change of income inequality, which has led to an increasingly widespread adoption of the middle-income group concept. An important driving force behind the rise of the middle-income group concept is globalization. The middle-income group defined by the absolute criterion model is different from that of the relative criterion model.
