[juniperus]

I’d imagine it was accounted for that these dam surveys are conducted for populations near a river, and they’re just comparing the dam survey of that area to administrative population estimates or whatever. Either way, this data might only be relevant for estimating riverside populations. Also, I’d say it’s more likely population estimates are overestimating the human population by a billion, not underestimating by a billion. That’s just my view of that though