http://www.bbc.com/news/magazine-30483762
“The Chinese economy is now worth $17.6tn, slightly higher than the $17.4tn the International Monetary Fund (IMF) estimates for the US.”
but…
“if you look at per capita spending power – the value of all goods and services produced within a nation in a given year divided by the average population for the same year – then, even adjusted for PPP, China ($11,868) is still lagging a long way behind not only the United States ($53,001) but also the likes of Turkmenistan ($12,863) and Suriname ($16,080).”
and…
“…how easy is it to accurately measure the size of the Chinese economy or even just parts of it?”
“Not very, ….distortions that happen at the village and provincial levels become amplified as they go out the statistical gathering chain.”
Moreover….
“The most important number in the world, for the past 30 years and next five years, is China’s growth rate. For 30 years its economy grew at a mind-boggling rate – roughly 10% a year but that stopped when the global economy hit problems in 2008 and it fell very sharply.”
IR Theory & Practice 