Actually, populationpyramid.net was one of the sources I considered when writing the article. I chose the data from a different source not for its eyebrow-raising implications, but because I think it is more accurate.

First, and as wrong as this sounds, generally speaking, a high birth rate requires poverty. Many Chinese are still in what you and I would consider poverty, but not by their own standards relative to past generations. I am expecting China to continue to progress technologically, and for their standard of living to continue to increase. This will result in a low birth rate.

Second, while China is now in the process of increasing the allowed number of children, the limit is still three (IIRC). Even worse is the fact that male children are still preferred to female children, and abortion of female fetuses - while less common - will continue.

Third, China's already AFAIK the only developed nation with a majority-male population, and it has been documented how this has allowed women to pick-and-choose from among suitors for their attractiveness and wealth...and so the onus is increasingly on men to prove their ability to provide the lifestyle the woman wants, rather than the woman providing lots of heirs for the man.

Lastly - and I did not provide much detail in the article about this point - but there are serious concerns that due to the nature of authoritarian government, lower-level functionaries are more likely to 'fudge the numbers' to show better results...and this includes for their national census.

One more thing - 480 million people is still a *lot* of people, especially given that half of China is at least as desolate as much of our western states are. The worst mistake we can make is to underestimate them.