Any chance of the regime cooking the books?
It's possible.
https://asia.nikkei.com/Spotlight/Society/China-census-called-into-question-over-14m-mystery-childrenTurns out that the 2020 Census counted 253.38 million children between 0 and 14.
Meanwhile, new births between 2006 and 2020 -- the period during which these youngsters were born -- total about 239 million, based on data from the National Bureau of Statistics. This gap of over 5% means slightly more than 14 million children somehow joined the 0-14 age group.
The once-a-decade count was slammed as "the most unreliable census" by Yi Fuxian, a reproductive science researcher at the University of Wisconsin-Madison in the U.S. and a critic of China's population control system.
The survey covers mainland citizens, excluding people in Hong Kong and Macao. The 5% discrepancy would make sense only if some 14 million foreigners became Chinese citizens. But even an official close to the Communist Party shot down the idea, saying it is just "not possible."
There are 4 explanations here:
* immigration of 14 million additional kids between 2006 and 2020. This can be ruled out 100%, because China is one of the most anti-immigration countries on the planet.
* birth underreporting error: authorities could have missed ca. 1 million births each year between 2006-2020, which would be a pretty big miss of 5-10% of all annual births - but who knows.
* counting errors during the 2020 Census: this is based upon the underreporting error over the years and there could be multiple counts of children by local authorities to bolster their regional influence.
* a deliberate faking and inflation of the birth numbers to avoid a grim demographic outlook to the foreign media.
While A) can be completely ruled out, a combination of B+C is very likely and even D somewhat likely.
If D) happened and they faked the birth numbers to inflate them, it will be the last time they can do so, because by 2030 the demographic collapse in China will be so immense with just 10 million births every year and 12 million deaths, that it's impossible to fake the gap.