97-104 - exact average not clear due to low quality data
The argument that China's poorest regions are doing badly on PISA is an old one, and the guy running PISA dismissed it more than a decade ago.
You can read the whole story here: https://www.ft.com/content/20770bf6-01e7-11e0-b66c-00144feabdc0 (just use www.archive.vn or some other paywall remover).
Here's the key quote:
"Citing further, as-yet unpublished OECD research, Mr Schleicher said: “We have actually done Pisa in 12 of the provinces in China. Even in some of the very poor areas you get performance close to the OECD average.”
Note that this was the 2009 PISA round, back when China was much poorer than today. So it is very unlikely that the poorer regions of China would do worse than they did back then given much better funding and better health outcomes etc.
IMO, your original estimate of 103-104 IQ is most likely. The mainland Han Chinese are genetically almost identical to the Han Chinese on Taiwan and I don't see anyone claiming the Taiwanese are double-digit IQ.
The argument that Chinese people are poorer because they have lower IQ is a muddled argument. A substantial portion of their relative poverty is simply borne out of the fact that smaller East Asian countries like Taiwan or Korea are essentially US vassals, which is often very lucrative.
China is simply too big for that, which means they have to re-invent a lot of low-margin industries because they'd get sanctioned otherwise. Their own domestic market is also too huge to rely solely on exports. A headache the smaller East Asians never had to face and could just focus on the high-value add sectors while engaging in massive currency manipulation even as Uncle Sam closed his eyes due to their vassalage.
That said, I think East Asians generally speaking underperform relative to their IQ. You can see this in a variety of ways, e.g. elite science production in the Nature Index (East Asians do worse on a per capita basis) or even nominal GDP per capita. Japan should be as rich as Switzerland given their high IQ. It just seems they have lower entrepreneurial and innovative capacities. It's certainly not an intelligence issue.
Why does this matter? New to your substack