What is the middle class? As a concept, a middle class person can have some income to invest, save, and only use some debt to sustain its living standard. A poor person relies on debt, and has little capacity to save or invest.
According to this survey, the middle class has reduced from 1971 to 2021 from 61% to 50% of the population.
The lack of a healthy economic growth and the rise in government debt seems to be the main causes for this trend.
For further information, read this article