* GDP in Purchasing Power Parity terms with added estimates for the size of the informal economy and adjustments for out-of-date GDP base year data.

But this is not the whole picture. World Economics has reviewed differences in the calculations used. A key factor is that the Base Year used in calculation of Chinese GDP is 2020, some 5 years out of date (compared with the equivalent American calculation using a more modern system that is right up to date). Starting with the 2026 GDP releases, China’s National Bureau of Statistics has adopted 2025 as the new base year for constant-price GDP calculations (covering the period 2026–2030). Historical data prior to 2026 has not yet been revised to the new base year, compared with the equivalent American calculation using a more modern system that is right up to date. An out-of-date base year suggests undervaluation. Much has changed over the period. World Economics estimates revaluing the Chinese economy to take account of the out of date base year would add roughly 7.5% to the size of China's GDP (for 2020-2025).

There is another factor also likely to make a significant difference (data suggests about 5.6%) to the measured size of economic activity: the difference in size of the largely unmeasured Informal economy (or Shadow economy) between the two countries. No prizes for guessing which country is likely to gain the most from the addition of its informal economy.

Making allowances for these factors, World Economics estimates that the Chinese economy is approximately 54% larger than of the United States, as of today.

So much for relative size. What about relative GDP growth in the past, IMF data shows Growth in the Chinese economy over the past decade, the past 5 years, and the past 3 years, have been consistently 2% - 5% higher in China than in the USA. On another measure, China's Share of Global GDP growth over the past decade has been approximately 30%, as opposed to the United States of America's 9.6%. On these measures, even a significant slowdown in China's growth will be unlikely to lead to parity with US GDP growth.

A final thought relates to the claim that China's economy is likely to slow down. Arthur Kroeber (founder of Gavekal Dragonomics and co-author with Dan Wang of the 2025 Foreign Affairs article “The Real China Model”), writing in 2025 sais: (


Anyone reading this detailed look at China's strategy and capabilities is likely to be unconvinced the great motor of global economic growth of the last four decades is likely to stop growing faster than America, any time soon.

It is quite possible, on relatively modest assumptions, that China's economy will be approximately 70% bigger than that of America by 2030. There are after all, as Elon Musk remarked, "a lot of smart, hardworking people [in China]". And in all probability over four times more of them than in America.

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