Demographic "Doomsday" Misses the Mark

(science.org)

41 points | by YeGoblynQueenne 2 hours ago

14 comments

  • daoboy 1 hour ago
    I've got whiplash from the speed at which we've jumped from overpopulation doomsday to demographic degrowth doomsday.

    It seems likely we lend too much credence to experts ability to model complex systems over a long period of time.

    • GuB-42 57 minutes ago
      That's the thing with exponentials, they are very hard to predict. We know that in general, exponential growth is unsustainable, and there has to be an inflection point, but where? It is usually difficult to know until the last moment, and even a small difference in time on where you predict the inflection point is can make a massive difference.

      Look at COVID for instance, not the first novel coronavirus infection, it only took days to go from "maybe it is like the other ones that infected a few thousand people" to "everyone on the planet will get it", because the start of the curve looks the same.

    • satvikpendem 1 hour ago
      You got whiplash over the speed of...a few decades? Malthusian theory had been proven wrong and people have known this since last century.
      • slibhb 1 hour ago
        The population hysteria from the 60s was proven wrong a long time ago but it's still pretty influential. E.g. it's not uncommon for millenials to talk about not wanting children because of overpopulation.

        It takes a long, long time for new ideas to diffuse through society. Most people are not paying close attention to the cutting edge.

        • awongh 55 minutes ago
          Even if there's a lot of scientific evidence, statistical proof etc. it's sort of surprising to me that when chatting with people all over the world (in dense cities and also in non-dense areas) how often I hear the sentiment that "there are too many people" and get the sense that they do mean that there's too many people in the world (not just within the surrounding 5-10km which might actually be true).

          This might also be one of those things that aligns with people's experience of the world, and the de-population thing is inherently counterintuitive unless you are, by definition, outside the norm- that is, you would only ever notice this if you live where people already don't live. (rural Japan, etc.)

        • boelboel 1 hour ago
          I think for most millenials it's an excuse not really the actual reason they don't want/get kids (although i think there's a few actual believers).
        • clark_dent 1 hour ago
          Millenials talk about not wanting children because they don't want to subject a new generation to this absolute shitshow of a planet, or because they can't afford the time and resources to adequately raise them.

          I've not heard anyone talk about an overpopulation problem in 30 years.

          • joenot443 52 minutes ago
            I'm a millennial and I really really like this planet. It's my favorite one. My kids are going to like it here too someday, I hope.

            My peers who are skipping kids are mostly doing so because their other ambitions don't align with raising a family, which I totally get. It's a huge trade off, I hope it'll be worth it.

            • RunSet 18 minutes ago
              "They had such enormous fun that they called for another elephant to come."
            • metalman 14 minutes ago
              gen x here, and my observation is that millenials tend to let there back brain say whatever the 'expected' response is,as having had it barked at them from birth makes it effortless, and then going back to bieng cagey,mildly subversive, and somewhat ferral in there actual lives. point if order : there is NO trade off in getting what you want.
          • dofm 17 minutes ago
            As a general rule they won't talk about overpopulation being a problem because they know that the population will likely peak within their children's lifetimes.

            They do talk about whether the earth can sustain that population as a reason not to have children. They are correct to. Their children might be the generation who have to explain to their children what fish tasted like.

          • slibhb 31 minutes ago
            > Millenials talk about not wanting children because they don't want to subject a new generation to this absolute shitshow of a planet

            They often list overpopulation as a reason. But yes, it's not the only reason they give.

            As an antidote to this kind of mindless negativity, just consider whether any individual human is happy to have been born. It seems very clear to me that most people enjoy being alive and so having children is moral on utilitarian grounds.

      • StableAlkyne 47 minutes ago
        > Malthusian theory had been proven wrong

        It was never proven wrong, as much as the world changed in a way that invalidated it.

        The entire idea was that population growth was an exponential function, whereas agriculture output was a linear function. There would have been famine if nothing had changed, because there is only a certain amount of physical labor a person is capable of doing, which has to be divided between the farming, logistics, and cooking of the food.

        What happened was that a century later we got mechanized farming and synthetic fertilizer, decoupling agricultural output from the population. Now a single person can do the work of thousands, and every year that number grows due to technology advances. It is too expensive to set up fully automated farms on the industrial scale, but it is technologically possible.

        But none of that invalidates his idea. If you believe that an exponential function and linear function sharing a point at (0,0) must cross each other (subject to other reasonable conditions like not having crossed yet, the linear having a positive finite slope, etc), then it is not logical to reject Malthus. It just no longer applies because we decoupled our food production capacity from the population size.

        • glenstein 35 minutes ago
          I mean insofar as the idea is about contemplating those mechanisms in the abstract, sure. But insofar as they were predictive or an attempt at a descriptive characterization of where populations would actually go, clearly it didn't hold. And if it didn't hold because it's true on it's own terms in some abstract sense, so much the worse for its inability to model changes that would prove to be relevant to actual population dynamics.

          It's also not just that we accommodated explosive populations but that eventually birth rates really did simply start slowing down for discernible reasons that future models were capable of integrating. Even if we continue to have technology that would give us the capacity to accommodate future increases in population, those increases are no longer happening.

    • glenstein 1 hour ago
      Well I wouldn't both-sides this one. 2020s population forecasting is better than 1960s forecasting, the latter was repudiated and the former is correctly modeling basically everything. Demographic decline really is happening and has reasonably well understood mechanisms.

      I suppose I would separate out some of the more extreme predictions about demographic collapse in Russia or China. I'm not sure what to make of those or if they're similarly credible to other kinds of population forecasts.

    • randusername 54 minutes ago
      It takes an uncommon breadth of perspective and depth of intellectual humility to contradict evidence it is your job to collect and interpret.

      Sometimes the trends of tomorrow just aren't in the data of today.

      What modeler in the late 19th century, when children were still economic assets on farms and in factories, could have predicted they would become extraordinary economic liabilities?

    • dsizzle 1 hour ago
      I think a lot of the difference is due to different groups/lead figures/experts focusing on different concerns, e.g. people like Paul Ehrlich and environmental groups focused on ecological sustainability vs people like Elon Musk and governments focused on economic sustainability
      • Amekedl 55 minutes ago
        yup. going by sustainability, we already have too many ppl on this planet. everything else is just "who pays my pension".
    • notnaut 1 hour ago
      Fear mongering / doomsaying has been a popular human tendency for as long as we have been able to record our interactions.

      If you’re vague enough about it, you can never be wrong! And if you’re overly specific and have a modest following of rubes with more money than sense, you can take some of it! A lot of it!!

    • thewhitetulip 59 minutes ago
      Exactly!! During my childhood I used to be terrified if population explosion

      Now that I have a kid, there is doom over population shrinkage

      Sadly this will be used by propagandaists to doubt scientists

    • lapcat 1 hour ago
      > It seems likely we lend too much credence to experts ability to model complex systems over a long period of time.

      You say "complex systems" but are actually referring to human behavior.

      Humans are unique in that they change their behavior in light of predictions. You can't make a prediction, and publicize that prediction, without changing the system.

      From what I've heard, many people are declining to have children precisely because of the environmental effects of overpopulation. There are of course other factors, but that's one factor.

    • dgellow 1 hour ago
      It’s more that we constantly extrapolate what experts are doing to the real world without taking in account the actual details. A research team comes up with a model that has some specific biases, parameters, etc. it yields some results. The result is then taken completely out of context and applied to a messy dynamic real world situation we don’t even have reliable metrics for. Then it just becomes a fight over narratives
  • gboss 54 minutes ago
    It seems to me that with natural selection, women who still choose to have children today despite having an education, employment, and all of the other factors that seem to harm the birth rate, their children will likely have as many children as they did or more, even with the same gift of modernity their parents had, and this issue will stabilize or we’ll resume population growth in 50-100 years.
  • samayashar 49 minutes ago
    This scares me to be honest. We have an exponentially decaying graph if we compare resources on y v/s consumption on x. I don't know what the next 50 years are going to bring considering the total resources to use on Earth are an "infinite constant".
  • ddoolin 1 hour ago
    Sounds like we could use a psychohistory expert.
  • DemocracyFTW2 1 hour ago
    the planet will be devoid of people on Tuesday, 5 May 3108

    Der letzte macht das Licht aus.

    • rs_rs_rs_rs_rs 1 hour ago
      What light? You're in Germany, it's illegal to use electricity for environmental reasons since 2050.
  • somewhereoutth 1 hour ago
    With a top heavy population pyramid, more resources have to be diverted to caring for the elderly, therefore less for raising the young - a self reinforcing mechanism.

    When actually given the choice, many women are choosing not to have children, for good reasons. E.g. disruption of careers, physical effects on the body, being tied to a partner, financial drain.

    Until we face up to both these issues, demographic collapse will continue - humanity will simply evaporate.

    • skybrian 52 minutes ago
      According to some people, AI will take most of those jobs anyway, so maybe it all works out in the end :)
    • Tyr42 1 hour ago
      .. humanity will be replaced by the subset of it which continues to have children.

      If a subgroup actually has children at above replacement, then as the other groups shrink, they will be a larger and larger fraction of the population.

  • api 1 hour ago
    I’m as skeptical of underpopulation doomerism as I was about the previous overpopulation panic.

    Both commit the fallacy of assuming present trends remain in place indefinitely and ignoring technology.

    They also both tend to be racist. Overpopulation was always about too many of the “wrong” people while underpopulation is about not enough of the “right” people.

    • orangedog 1 hour ago
      How is South Korea's very low birth rate about not having enough of the "right" people? Perhaps they could allow mass immigration to fix it but that would destroy the culture. The issue is happening everywhere, how is it racist?
      • awongh 10 minutes ago
        The racist part is thinking that the confucianist misogynistic hyper capitalistic culture is worth protecting in the first place, as if Bangladeshi, Indonesian or Filipino people living in the same country as you will somehow be the thing that is the end of "Koreanness" and not all of the culture's inherent issues itself- the other kind of end of Koreanness (the implied preferred end) is when almost everyone who is Korean dies out. (Which, to be clear, is not limited to Korea- it's the same set of issues everywhere people complain about "immigrants")
      • DaSHacka 1 hour ago
        > Perhaps they could allow mass immigration to fix it but that would destroy the culture. The issue is happening everywhere, how is it racist?

        Well, there are people that think the idea of preserving cultures itself is racist (well, at least western ones), or that there is no detrimental effect to an existing culture by enabling mass migration.

        • glenstein 42 minutes ago
          I think the racist part is the pivot from demographic changes to the inference that they herald an extinction event for a particular culture, and especially tying that assumption to unwarranted extrapolations that misread the data, and especially when it's a fixation on populations that don't realistically face any such threat but nevertheless talking about the perceived threat in existential terms.
          • DaSHacka 3 minutes ago
            The racist part is extrapolating from mass-scale migration of different demographics and cultures that it will cause demographic and cultural change? You may disagree it is a problem, but I fail to see how it isn't true.

            You think if, say tomorrow, all 1.4 billion citizens in China were teleported into the U.S., that there would now be 1.7 billion Americans, indistinguishable from the Americans that came before? Or, would it simply be 1.4 billion Chinese, alongside ~300 million Americans (if we're being generous...)?

            Demographics and culture are obviously intrinsically tied, each individual migrant holds beliefs and values that have been forged and shaped over the span of the lives that they have lived in their country of origin. This is, and has always, been the case, its just more of a hot-button issue recently because:

            A: We are currently getting an overwhelming amount of migration to stave off our own demographic issues, so the strain begins to have a more noticeable impact,

            and B: Many of the migrants (from abroad) are coming from countries with cultures intrinsically incompatible with values Westerners have come to expect in their own countries (See: Sharia Law as contrasted with Women's Suffrage), so they stick out somewhat like a sore thumb when advocating to enact such policies and practicing such cultures.

      • api 1 hour ago
        I'm not saying there's zero problems. Both too-rapid population growth and too-rapid population decline can cause problems with social stability and economic systems. I specifically called out doomerism.

        South Korea's birth rate is indeed dangerously low and threatens their economy. If they cared they could do something about their extreme workaholism and cost of living.

        As far as immigration destroying the culture: it depends on the rate. A healthy but limited rate of immigration revitalizes cultures, but it's pretty clear that sudden mass immigration is dangerous and causes a lot of problems and backlash.

        Speaking of fixing problems... if our billionaire class who seem so worked up about birth rates wanted to do something about it they could also address the most frequently cited problems preventing young families from forming. Like housing prices.

        If we really get into a situation where dangerously low birth rates are threatening the economy and social stability, the boring solution is to do what we do for other goods and services that the free market isn't adequately providing: directly subsidize it. Pay people to have kids. The easy way would be a payment or tax rebate to married couples with 0 children to have one child. But that's the boring solution that doesn't involve massive reactionary cultural transformations, so the right-wing "problemists" won't like it.

        Edit: by problemism I mean people who use a problem as a lead-in to push only one solution, and they're not actually interested in solving the problem unless it's their solution. An example from the left side of the spectrum would be Marxists for whom any solution to climate change that doesn't destroy capitalism is unacceptable, or anarcho-primitivists or anti-tech trads for whom any solution that doesn't involve shutting everything down is unacceptable. In reality the solution to climate change is to emit less carbon, and physics doesn't care how we do that or what political system we are using.

        There's a lot of right-wing problemists for whom any solution to excessive population decline that doesn't involve taking rights from women and re-introducing reactionary theocratic or nationalist structures isn't acceptable.

        • boelboel 49 minutes ago
          I don't think financial incentives will actually do that much, it's generally seen as something that works only marginally. People get more kids when they get stable/good jobs, have a support network, have a culture that incentivizes births.

          South Korea is currently throwing money at the problem, upped parental leave even did some things to make it easier to retire if you got a lot of kids. I'm almost certain these things won't meaningfully change the situation (maybe go from 0.8 to 1.0) as all korean children are expected to get good jobs (white collar, certain professions) , they structure their society towards this and it's impossible to get a high birthrate like this.

          I actually read about how something like presence of nuns in your town in italy was quite correlated with birthrates as it basically relieved all women but the nurses of some duties. In Korea you can see how the stability leads to a very significant effect on birthrates as Sejong is by far the highest birthrate region. Interesting since those really obsessed about birthrates also seem to hate the worker protections that make it difficult to fire people. I guess housing is another of those stability factors since renting really ups the risks of children.

  • lenerdenator 1 hour ago
    The real "doomsday" is the fact that we no longer have the population growth to sustain the increases that markets demand while simultaneously not alienating the ever-loving hell out of the labor and customers that capital depend upon for those increases. It's already leading to socio-economic and political problems.
    • satvikpendem 1 hour ago
      That's where robots come in. They replace the missing labor.
      • beej71 15 minutes ago
        As long as the robots are paying into social security, I'm good. ;)
      • 233mhz 1 hour ago
        idk if I'm not naive enough or too naive but I fail to see how you can expect such a simplistic solution to just solve all the problems mentioned knowing the first, second, third, &co order effects

        Politicians in the 70s were selling us the 3 days work week and retiring at 50 thanks to "automation", I fail to see how the "robots will solve all our problems" logic is any different.

  • PowerElectronix 1 hour ago
    "The great vice of the Greeks was not sodomy, but extrapolation"
    • misko77 1 hour ago
      Unrelated, but I do like to place my trust in internet strangers - is Ignition! a read you'd recommend?
  • cubefox 1 hour ago
    The article assumes the original 1960 paper by von Foerster was a serious prediction. It wasn't. It was a joking example showing that fitting hyperbolic growth models do data leads to an absurd singularity, an infinite population in finite time. A much better write-up on it is Scott Alexander's "1960: The Year The Singularity Was Cancelled": https://slatestarcodex.com/2019/04/22/1960-the-year-the-sing...

    Scott's conclusion (written in 2019, a year before GPT-3 was published) is perhaps more interesting today than it was then:

    > In other words, the singularity got cancelled because we no longer have a surefire way to convert money into researchers. The old way was more money = more food = more population = more researchers. The new way is just more money = send more people to college, and screw all that.

    > But AI potentially offers a way to convert money into researchers. Money = build more AIs = more research.

    > If this were true, then once AI comes around – even if it isn’t much smarter than humans – then as long as the computational power you can invest into researching a given field increases with the amount of money you have, hyperbolic growth is back on. Faster growth rates means more money means more AIs researching new technology means even faster growth rates, and so on to infinity.

    > Presumably you would eventually hit some other bottleneck, but things could get very strange before that happens.

    • glenstein 1 hour ago
      Great link, thanks. In a pretty remarkable coincidence the post you linked, which itself is from seven years ago, considers a prediction from over 60 years ago of an anticipated doomsday, and that doomsday date just so happens to be a few weeks from today:

      >In the 1950s, an Austrian scientist discovered a series of equations that he claimed could model history. They matched past data with startling accuracy. But when extended into the future, they predicted the world would end on November 13, 2026.

      Set your calendars!

      • l3x4ur1n 57 minutes ago
        Oh no, 21.12.2012 all over again
    • mcphage 41 minutes ago
      [dead]
  • binlog 2 hours ago
    Relevant xkcd - https://xkcd.com/605/
  • hn9zmdcaou 2 hours ago
    Spent a few years doing population projections for regional planning and the thing that always got lost was how sensitive the long run numbers are to small fertility and migration assumptions.
    • rcxdude 1 hour ago
      Exponentials, let alone super-exponentials, will tend to do that. As the article notes, the biggest issue is assuming that the system you're modelling doesn't have any negative feedback loops that would stabilise it.
    • david-gpu 1 hour ago
      The same is true of investment and retirement calculations. Little differences in the estimation of an exponent will compound to huge differences in the long run.
  • hizlikovboy27 1 hour ago
    [dead]
  • bemtevi 1 hour ago
    I think we're already at a doomsday for population. The inertia of such a large world running on capitalism means we can't do anything about our problems any more, so I feel the bullet has been effectively fired. We're just watching it in slow motion.
    • weichi 1 hour ago
      I'm not sure what you mean by "capitalism", but the only reason the world's population is so large is that critical technologies like steel, cement, and nitrogen-based fertilizers have been deployed widely. Free markets and the profit motive have been critical drivers of this wide deployment. There are problems with these industries being so strongly profit-motivated, but it seems difficult to figure out what to do about those problems while maintaining current populations levels and material prosperity.
      • 233mhz 1 hour ago
        > it seems difficult to figure out what to do about those problems while maintaining current populations levels and material prosperity.

        Pretty sure that's the point of the comment you're replying to.

      • bemtevi 1 hour ago
        Capitalism means we can only take actions that benefit individuals in the short term (so, arms race). And the large population means inertia in that incorrect direction.
    • satvikpendem 1 hour ago
      This is a Western view not necessarily seen in Asia, such as China which does seem to be solving their problems just fine.
      • bemtevi 1 hour ago
        Seriously? China is one of the top polluters and it's a horrible country to live in. No one is solving climate change. The problem is worse than ever. None of the serious problems are being solved. Only made worse.
      • xienze 1 hour ago
        You're making the mistake of not looking down the road far enough. "China's developing rapidly and has all these cool EVs, looks like smooth sailing til the end of time for them!" Their male/female imbalance and TFR < 1 are absolutely massive looming issues. Maybe they'll advance to the "robots do everything and no one ever has to work" end-game and then those things won't really matter, but I wouldn't bet on it.
        • boelboel 47 minutes ago
          The robot thing was also what japan bet on in the 90s
    • kakacik 1 hour ago
      Yet it will somehow work out. Not ideally, thats just not humane way, in fact probably quite messily, but folks in few decades will look back on whats just another period of history. Some ups, some downs, some mild and some a bit extreme, and thats about it. Moving on, next batch of challenges ahead
      • gpvos 1 hour ago
        It looks like both the climate and biodiversity will be a lot worse than now (with appropriate great migrations). Not sure what is able to compensate for that. Although indeed humans appear able to adjust to any kind of environment.
        • MrLeap 55 minutes ago
          AI agent diversity will be on the upswing, so we've got that going for us. We'll also be more insulated from the climate by virtue of all of our bodies being lashed together into a machine and flesh lattice controlled by the executive overmind.

          What remains of humanity will be safely cocooned inside the biomechanical membrane between the chaotic outside world and whatever environment the compute prefers. The perspiration of its leviathan breaths and a circulatory system that pumps coolant will ensure the temperature differential.

          Like how single cell organisms were engulfed into multicellular organisms, so shall our descendants be engulfed. Countless immobile interconnected bio-systems with humanity as its ancestor. They'll less adaptive than us but more optimally specialized. I wonder how recognizable humanity would be when we're tessellated into one large interconnected amalgamation. Furthermore, I wonder how many generations we have left where we'll still need a face and outward looking eyes. Skin cells don't need flagella after all.

      • boelboel 1 hour ago
        Although I think there's a good chance that this will happen there's no reason to assume that we'll be better or at most slightly worse in the future just because that's all we've experienced in (recent) human history, it's a sort of survivorship bias.
      • Ekaros 1 hour ago
        Things will stabilise somewhere. Not sure at what population level and what technological level. But I am sure at some point they start to rise again. It won't be downward trend to zero for forever.
      • bemtevi 1 hour ago
        I do think so, but like you said, messily.
      • watwut 1 hour ago
        > folks in few decades will look back on whats just another period of history

        I mean, of course. I also worry about French Revolution and WWII less then people who had to live it.