The problem is mostly one of data availability. China has plenty of data, but not all of it is credulous. That, and the fact that comparisons of any two nations will always be susceptible to the accusation that the data has been "cherry-picked" to show a favorable result.

But the global data on poverty is basically unassailable. Poverty has declined absolutely everywhere. The rising tide lifted at least the very poorest boats, whatever can be said for the American middle class notwithstanding.