[tanzirian]

The numbers in those maps are based on purchasing power parity not actual wealth of the nations. Purchasing power parity is good way to compare standards of living when per-capita-GDP or per-capita-GNP is concerned but is not a good way to compare the actual total wealth of nations. But undoubtedly China will be the world's largest economy in actual dollars some time this century. Since China's population is about four times that of the US, China will need an actual (not purchasing power parity) per-capita one fourth that of the US to draw even in terms of total actual GDP.