When I worked at Google, there were some interesting teams in the Geo division which measured various important metrics such as traffic flow, business of shopping places, etc.

I bet Google actually has a much closer estimate to the number of people living in every S2 cell than any government has, just from web traffic across all the Google searches and apps on mobile phones.

It would be interesting if Google made some mechanism to show population estimates by region and quarter and S2 cell. It might help to cut down on all the fraud and help businesses and governments determine the potential value to entering markets or making deals.