However, purchasing power parity strength does not mean the country would or should do better with a stronger currency. The country has to import 10 million barrels per day in oil.

The previous article notes the exchange rate weakness in China. The RMB got weaker. This dropped China from $18 trillion to 16.5 trillion in GDP. It also noted that Italy and Japan are dropping in the GDP ranking.

Yes, purchasing power parity wise, China's citizens have far more ability to buy things than officially reported. So the exchange rate could go up and China economy could still be good. However, exchange rate GDP and exchange arate are separate and more complicated things. A nations ability to buy imports like buying oil etc… Soviet Union collapse was not able to pay cash to UK for grain. Having hidden purchasing power parity economic strength now or ten years ago is irrelevent to a collapse taking out economic strength. This collapse being the population aging out and losing productivity. The after-effects of the one-child-policy means accelerated age out and drop in productivity of older workers. ten years ago everyone productive with an average age of 34, now things are at 38.7 but is going to 47 by 2040 and then 55 by 2070. Working age population shrinking 1% per year.

So they were and are stronger than they claimed but the fall could be harder and sharper. The declining countries Japan, China, Italy are the older population countries with shrinking populations. More old people in general and really old people dying. I can be very strong when I am 38 but I am less productive 55 and I am retired or very unproductive 65-70 and maybe I am dead 75-90. And I am close to useless (for economic work, having a job etc…) 5-10 years before dying in most cases.