In the WSJ today, "China’s income tax system is coming under growing scrutiny from academics and other commentators worried about the country’s widening wealth gap."
Well if the wealth trickling down effect isn't happening. The rich is trapping a lot of wealth, and have not entrepreneurially created ways for those below to level up, then the government is coming with strokes of the pen to change the law to make it happen.
How would the wealthy respond. They will figure out ways with their bankers, lawyers and accountants to hide or squirrel away their money. Keeping what they have gotten feels better than using it to help others.
The economic theories are wrong about human nature and so the desired results aren't forthcoming unless you employ extra-market measures.