alt Hacker NewsIt's interesting that China does not have exact data. Don't they require everyone to register their address? I know foreigners must do it, and chatting with the locals they told me they were registered as well.
I would have imagined that the data could be used to get mostly accurate numbers.
Even if they required it that's no guarantee people actually do it. I have lived for a couple of years at an address different than the one I was registered at. Illegal in my country, but easy to conceal. (I had to because the apartment I lived in didn't strictly allow people of my sort to permanently reside in it.)