Population much more than 8.2B, rural areas underestimated
42 comments
·March 21, 2025jdietrich
zamadatix
Concerningly, they acknowledge accuracy of the numbers reported by the dam projects under limitations... by only highlighting the opposite, that it could be under-reported by them. I feel like I'm missing a lot for this to have been published but I'd expect such a paper about limitations of existing studies to be especially heavy on what the limitations of this new method might be.
https://www.nature.com/articles/s41467-025-56906-7#:~:text=L...
MichaelZuo
I’ve actually looked into this for a few developing countries, and dam resettlement figures are very likely to be inflated.
There’s no actual combination of outsiders going around to every household in every village for even a dozen days of the year to plausibly provide a third party confirmation of claimed residence for each individual.
It’s effectively villagers certifying each other that they really live there as a primary residence.
lurk2
One of the more frightening things I ever learned was that if the population of China began walking in front of you at a rate of 1 person per second, it would take approximately 31 years for the entire population to pass you.
The math, roughly:
1 billion people (there are more now, but we’ll call it an even billion) / 60 seconds ≈ 16,666,666 minutes
16,666,666 / 60 minutes in an hour ≈ 277,777 hours
277,777 hours / 24 hours in a day ≈ 11,574 days
11,574 / 365 days in a year ≈ 31 years.
That’s just China. The global population would take around 220 years, with not so much time as to say hello. A bureaucracy can of course delegate census reporting such that the groups become manageable, but it puts a lot of things into perspective when you understand the sheer scale of the human population.
more-nitor
> It’s effectively villagers certifying each other that they really live there as a primary residence.
this. some smart asses would be calling all their relatives, distant-relatives, friends, etc AND claim that they all lived there. then, share the loot(?) like 50%, 30%, 20% etc
the more better approach would be compensating by property, though does have its own downsides
kristjansson
A dollar per dead snake, you say?
lurk2
I saw this happen on a Minecraft server. It was an economy simulator based out of Sweden or Denmark. The administrator was committed to Keynesian economics. One day he wants to clear a desert to build a new town. To compensate people for working there, he used a plug-in called Shop Chests, allowing users who deposited 64 sand into the chest to receive 100 units of the server’s currency. This was substantially more than the sand was worth on the open market. Since this guy was a Keynesian, he had also built a government marketplace that bought and sold all the major blocks. Rather than spending the afternoon digging, I warped to the market, bought out the entire supply of sand, warped back to the job site, and sold the sand at the higher price.
This kind of thing happened a lot with absentee owners who would set prices for their shops lower or higher than the market price. If the owner had set up hoppers underneath the shop chest, you could effectively bankrupt him overnight. It happened a lot with minecarts, diamonds, colored wool, and things like that.
kristjansson
Which is why the likes of Eve Online employ real-life economists - is easy to get wrong.
Cobras aren’t really an arbitrage problem, except in the sense that the reward was (presumably) more than the cost of breeding them.
soulofmischief
History often rhymes because we clearly aren't teaching it effectively enough. Every six-year-old schoolkid should understand the Cobra Effect (perverse incentive) and how to recognize it around them and in their own thinking.
null
pessimizer
Are you saying that large infrastructure projects have been systematically overcounting population in order to pay more compensation? That there's an interest in making them seem more disruptive, and as if they displace more people?
If that's an obvious conclusion, I need more explanation.
solid_fuel
It doesn't need to be top-down corruption on the part of Dam Corp, LLC.
Think about it this way - you and your family live somewhere and are being displaced to make way for a dam, some guy in a suit comes around and says "we'll pay $1000 per resident to move you somewhere else".
Maybe your uncle lived at your house with his wife for 5 years, until they moved to the city last year. Your grandmother lived there until she died 6 months ago. So lets say it's just you, your partner, and 2 kids.
But, that's a lot of money - do you tell the man in the suit that your house has 4 residents, or maybe stretch the truth to 5 or 6 (your uncle might move back soon, after all)?
And remember, corruption often stacks - individuals might add an extra person here and there, but then the local relocation manager adds a few % to get a little extra on top, and their boss adds another few %, and so on... soon you're seeing 25% more people than actually reside there.
Muromec
Chekhov, "Dead souls". The scam can go both ways, you need to be local to know how it works and not benefit from it enough to snitch.
allturtles
The issue is that the availability of money gives people an incentive to be counted, even if they don't live there.
00N8
No, I think the conjecture is more that people from the surrounding areas could be claiming residency in the affected area to receive the payouts, even though they normally live elsewhere.
AnotherGoodName
The way i see it people really do often live in multiple locations at once and bureaucracy has a hard time with that fact. Think of the itinerant workers travelling around for seasonal jobs. The census might count them in one location but it’s quite reasonable they count for the relocation too.
So it’s possibly a matter of edge cases in the wheels of bureaucracy than outright graft.
Muromec
Likely the manager who makes the payouts happen and not people themselves
kmeisthax
No, it's the people being resettled who have an incentive to overcount themselves.
rendang
I've typically heard it rumored that populations get overestimated, as corrupt local officials in developing countries want to get more resources/power allocated to their district
TwoPhonesOneKid
That seems like the kind of behavior that would drastically vary from place to place and culture to culture. Just compare Rwanda with the DRC, for instance—neighboring countries with nearly polar-opposite reputation of how corruption is expressed. The DRC's corruption (aka Tshisekedi) means very low centralized control and an incredibly brutal multi-front civil war. Kagame's style has led to one of the most authoritarian countries on earth, albeit one with very low crime rates. That these are bordering countries with overlapping cultures and peoples and these places produce such wildly different expression of societies (as of today, that is) is quite illustrative.
There are certainly some ways that the behavior of countries can be painted with a wide brush, but each country still has unique dysfunctions and strengths. It's very difficult to say anything broadly applicable that doesn't have glaring exceptions undercutting the premise.
This is especially, especially true in places with great restrictions on freedom of the press—Rwanda's image is almost certainly partially fabricated, but it's very difficult to interpret the state of affairs from outside the country.
Corruption is certainly a constant across all countries, but the form the corruption takes is very dynamic.
wongarsu
The original paper is discussed here: https://news.ycombinator.com/item?id=43398308
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
lenerdenator
Well, is it a few million, or a billion?
It doesn't really say in the article.
wongarsu
If the paper is accurate and not falling prey to false assumptions or some other error we are talking about billions. If we just generalize the deviations claimed by the paper out to the entire world there are about another 3-5 billion humans. If the paper is accurate but doesn't generalize to other countries we are still talking about a billion people.
johnea
I had the same question.
I thought reading the paper in Nature would give some more insight, but no.
I was looking for at least an estimate of what they thought world population should be, but that doesn't seem to be included in any of the text...
oskarkk
Because estimating the world population wasn't the point of the paper, and extrapolating their results for the whole world wouldn't be very good science. But discussing something that the paper authors didn't discuss makes a good clickbait title. Especially with the title here on HN, which presents the possibility as a certain fact.
Newlaptop
Frustratingly problematic headline, I'd expect better from Popular Mechanics.
The title "Oops, Scientists May Have Severely Miscalculated How Many Humans Are on Earth" is entirely misleading- it's not "scientists" who have miscalculated this, it's government bureaucrats in various countries who are responsible for collecting and reporting census information in their region.
This matters, because we live in a world where many people get much of their information only from headlines, and a recurring narrative of "Scientists make mistakes" or "Scientists can't be trusted" has real impact to policy on climate change, vaccine hesitancy, and other areas where distrust of scientific knowledge or expertise causes uninformed people to make decisions harmful to their own well-being or harmful to those around them on everything from nutrition to pollution to evacuations before hurricanes.
lurk2
What distinction are you drawing between government bureaucrats and the scientists who use their data? If the thesis is correct, then most demographers are wrong about the world’s population. The bureaucrats themselves might not be scientists, but the demographers surely are.
This is a thinly-veiled ode to the “trust the experts” paternalism that dominated the early 2020s. This attitude isn’t scientific, it destroyed the trust in the scientific method it claimed to want to preserve, and it resulted in many policies that courts have since ruled to be illegal.
casey2
The government bureaucrats in this case are usually scientists employees by the government. And as far as I'm concerned anybody using the scientific method is a scientists, and if they aren't then they aren't, job title is meaningless here.
Stop pretending that scientist should be trusted. The recurring narrative you complain about is true and it's what separates science from dogma.
Scientists are experts in incredibly narrow fields and almost always speak about topics they have no knowledge of, even more dangerous, they convinced themselves and others that they have knowledge of these topics because they are superficially similar to something they know well.
teaearlgraycold
The article doesn’t really give much scientific information. But wouldn’t areas flooded by dams be much higher in population than other areas? They would be by rivers and within valleys. Protected land with a fresh water supply. What relative population increase did they assume for these regions?
insane_dreamer
Doesn’t every country or at least major country conduct censuses? Assuming there are some countries that can’t or don’t due to conflict, lack of resources etc. it seems these would be limited and therefore whatever estimates are made for those countries would be off my millions but certainly not billions.
Ekaros
No. Some countries don't need "census" as every citizen is sufficiently tracked and must report their official address. And so would most migrants. Meaning that with modern computer databases you can track births, deaths, immigration and emigration down to single person.
epolanski
I'm not aware of any country not doing censuses regardless of their digitization.
Censuses aren't just counts, they are timestamps of lots of data (education, family, etc) which is often missing, not digitized or not available (you may graduate in a different country, you might be living with someone but not be married, etc).
There's also a privacy/anonimity issue, even when data is available it can be used for very little over than counting.
insane_dreamer
Ok but that is even more accurate than a census. So which countries are these uncounted people located?
>"When dams are built, large areas are flooded and people need to be relocated," Láng-Ritter said in a press statement. "The relocated population is usually counted precisely because dam companies pay compensation to those affected."
Sure, "we've been systematically undercounting population for decades" is a more plausible explanation than "large infrastructure projects in rural areas of underdeveloped countries are a bonanza of corruption".