The middle class exerts a stablizing influence on society. But in China, people in the middle-income category are far from playing the role that the middle class does in developed countries. Why? Because economic status alone does not make the middle class, says Yu Jianrong, a sociologist with the Chinese Academy of Social Sciences (CASS).

The middle class is considered an important part of society because its ratio to a country's population decides the economy's vitality and the availability of good jobs. It acts as a buffer between the rich and the poor, too, without which social conflicts would intensify.

Three decades of China's reform and opening up have resulted in a booming economy and brought about great changes in society. Though indices such as the average annual income suggest medium-income people's earnings have not risen sharply, Yu says there's no denying that the number of such people has been growing year after year.