I referred to the 2015 PISA test when making those estimates. In 2015, four Chinese provinces took the test including Guangdong, which student's native language

I referred to the 2015 PISA test when making those estimates. In 2015, four Chinese provinces took the test including Guangdong, which student's native language is often not mandarin. Their total population is 230 million people. Granted, they are likely above China's average in terms of skills but I read elsewhere that someone involved in PISA said regarding about unofficial PISA 2009 research in other Chinese provinces that even some very poor regions scored close to OECD average. We will likely see China's whole country results in 2019 when PISA 2018 official results come out and I believe it will still be better in math than many OECD countries. Your point regarding lower average quality of education in China could be true but that means in 10 years they could be improved with economic development and their skills would be even better than now. Developed countries in East Asia and Singapore where populations share the same cultural traits with China have for some time dominate PISA rankings in all subjects. India has many talented people but because of many factors, as a percentage, the figure is probably many times lower than China. Check out their former PISA results before they pulled out. They will improve but it is a long way to go and we know from history that network effects and other factors tend to make tech dominance into natural monopoly, at least until a major paradigm shift happens. No other country has both the size of native population and the distribution of population's skill levels taken together to compete on equal footing with China in the next 1-2 decades. The US can hold its own and perhaps keep the lead by being a desirable place for global top talent but it remains to be seen if the government's policy and other factors will erode that advantage away.