Before revision:  The effect of economic stratification manifests in a characteristic multimodal form of the histogram of wealth distribution. We observe such a multimodal pattern in empirical data on wealth distribution for  urban areas of China.
After revision:  The effect of economic stratification . The stairs represent wealth levels of economic classes separated by wealth gaps. As we show, the pattern is typical for macro-economic systems with a limited economic freedom. One can find such a multimodal pattern in empirical data on wealth distribution for urban areas of China.