Declining Fertility
Recent research suggests there will be a significant reduction in the birth rate over the course of the next century. What would this mean if it were true?
In this podcast we discuss the accuracy of population forecasts, the assumptions they are based on, and the relationship between the number of people and factors such as productivity and societal innovation. We also attempt to predict some of the implications of an aging population with fewer children and ask whether there is an optimal number of human beings.
A few things we mentioned in this podcast:
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Transcript
Hello and welcome to the Cognitive Engineering Podcast produced by me, Fraser McGruer of Aleph Insights. In this series of podcasts, we take a look at interesting topics and discuss what we think they tell us about analysis and decision making. I'm here with Chris Wragg and Nick Hare of Aleph Insights, and this week we're discussing declining birth rates due to the lockdown. Unusually, we're recording this remotely. Chris, I believe you've got an article,
Speaker B: of decades. And while in the: Speaker C:What would that look like? How many 80-year-olds do you need per five-year-old for it to be a fair
Speaker B:fight? It's a good question. Are dimmer frames allowed or not?
Speaker A:Right. Okay. I mean, there's so many interesting points that you can spin off this. Nick,
Speaker C: t just be worth mentioning in: Speaker B:absolutely. I mean, some of the speculation around this article was talking in very, very speculative terms about could we just continue reducing until the population, the human race, no longer exists. Now, that kind of forecasting, clearly, we're going to adapt as things happen, I mean, there are lots of historical examples of birth rates changing in response to environmental conditions and so on. And we can only imagine that the same is true. So, I mean, their modelling was more sophisticated than simply saying, look, here's a line for birth rates. There you go. Look at that. That's going to be bad, isn't it? Or good, perhaps. Maybe we do need fewer people. I mean, that's one of the things we can discuss. But as Nick said, right to heavily caveat this with, we're clearly going to adapt to
Speaker A:the circumstances we find ourselves in. Yeah. But I think, as you were saying, this sort of begs all sorts of interesting questions about what is a good population number? What are the
Speaker C:potential side effects? And I think it's probably worth delving then into the sort of mechanisms where, you know, what do we expect population level to affect? One thing it's worth disposing of, because it's so prevalent in the history of sort of naive economic thought is the lump of labour fallacy, which this is a sort of a bit kind of reverse version of it. But the lumber labour fallacy says that there's a certain amount of work that needs to be done. And if you get e.g. a machine to do it, that means some people must be out of work as a result. And that, you know, if we have more population, the problem is there won't be jobs for them, because other people, the existing population will be doing all the jobs, and the new people won't have jobs.
Speaker B:Now, that's completely... Also known as the Jeremy Corbyn fallacy.
Speaker C:Right. That that is completely incorrect, right? So that we know that that's historically, the economy has always expanded to fill the number of people we have. But there are some important elements of, you know, sort of looking at how numbers of population affect welfare. And first of all, on a very basic level, you know, the more people you have, by and large, or in the long run, and over the grand scheme of things, the lower we would expect their average income to be under sort of standard economic models, because of declining returns to scale, essentially. So you know, if you double the population, this theory, this sort of basic approach would say, you are not going to double output, you're going to do something less than double output. However, that may not be true. There may be other effects, externalities, network effects. So it could be the fact that it could be that, you know, when you have 10 people in an organization, to some extent, you produce more than, you know, 10 nights of when you have nine people. And one of the key, one of those key externalities is innovation. And there's a lot of fairly plausible, although it's quite surprising, but plausible theories that say that essentially innovation is a result of the number of people you have. Because innovation happens because certain ideas pop up almost at random. But the more people you have, the more probability you have of getting a good idea, which will advance productivity. And so more global neurons. Exactly. And actually, the weird thing is, when you try to model, you know, innovation and speed of productivity growth, using population, it works really well. So now I'm not committing 100% to that. But I think it's an interesting, it is interesting. And we're thinking about that actually, if we have population declining, we might see lower productivity growth as a result, even though in the sort of naive approach might be to say, well, there'll be more stuff to go round. So you know, it'll be okay. But actually, we might expect to see lower growth. But I think in the in the short term, the most the obvious cost is, as Chris alluded to this, this problem of, you know, of the difference in the sort of top heavy age curve. Old people are, I mean, people talk, I know a lot of narrative about the NHS is about cuts, and stuff. Well, there haven't really been cuts in the NHS budget, not significantly. The significant thing that has happened over the last sort of, you know, couple of decades has been a massive increase in the number of old people living, living to be old. And I think an 80 year old costs something like 10 times per year. On average, an 80 year old costs 10 times more than like, you know, a 30 year old in terms of health. So I think the challenge, from that point of view, there's a there's a social one political one, could this exacerbate the generation gap? Are young people going to feel increasingly, you know, like they're supporting this huge weight? But also, a technology challenge of, you know, how, how we can we make health, we don't just want people to live longer, you know, to make them be productive for longer, in order to sort of compensate for the for the large, vast number of people.
Speaker A:Perhaps we could perhaps we could have some kind of system where we had like, a little sort of diamond type thing in our palms of our hands, and that changed colour over time. And you know, when it gets a certain colour, off we go to the rapture.
Speaker B:Are you carrying all Logan's Run on us?
Speaker A:Yeah, I certainly am. Chris, let's hear about the implications of an ageing population. Either tell us more about that. Any thoughts you've got on that? Or any further examples?
Speaker B:Yeah, well, I think fertility rate itself is isn't just an interesting thing. So I think that would be probably the thing that people would would fixate on, right. And, you know, if you look in, if you look in all of the sort of thought experiments that are done in literature, you know, they, they don't generally paint a good picture of when fertility rates go down. And, and the fact that we measure fertility rates by the amount of procreation per woman, suggests it's going to be perceived as a as a, an issue attached to women. And if you look at, you know, like I say, if you look at fictional examples, things like Children of Men or Handmaid's Tale and Testaments, you know, in Handmaid's Tale, the pretext for establishing Gilead is largely about, you know, falling reproductive reproduction rates.
Speaker C:It's a bit awkward, but I don't have someone explain to Chris about that men are involved in reproduction.
Speaker B:Yes, no, I was aware of that. But the point is, but it does focus on women. So the, so the the sort of brunt of it, even though it is, and this is brought through in, you know, Atwood acknowledges this, that actually, you know, the infertility in most cases is probably associated with the men in position, but it's it's tied to the women. So I think there's, you know, one of the issues that's, that's potentially going to sort of come into play is that it will be seen as a sort of woman's role, you know, the women's role to fix this, and that there could be some quite, you know, quite draconian things that occur. And if you look at the flip side, so like, you know, and you say, oh, well, that's, you know, maybe that's a bit far fetched. But if you look at things like policies that have actually occurred, so this is almost the reverse problem, but the one child policy in China, right, you know, that was to decrease reproductive rates, you know, to try and limit the population. And there's quite a lot we could probably learn from that. But in terms of the policy implications of that, you know, you saw all sorts of quite extreme things like, you know, enforced sterilization and abortion. You infanticide, you know, in rural communities of female children, a skewing of the gender difference. So different places will, if this happens, you know, different places will react to this in different ways. And some of the ways that could happen could be really not great. Equally, you know, we're already, you know, the UK is down to, I think, 2.1. We're literally at the point at which we're not going to increase our population by our own reproduction of those people here at the moment. And that's kind of, you know, that's kind of just happened benignly, you know, and that's been fine. So, you know, I think the social implications, as you know, Nick talked about the economic implications, I think the social implications could be profound, but they'd probably be pretty patchy.
Speaker A:Yeah, yeah. Nick, what do you want to move on to?
Speaker C:So we don't normally think of population as something the government should be overly concerned with, by which I mean the level of population. It obviously has an impact, it's a significant political issue when we talk about immigration. But governments do not have a target for what the UK population should be. And, you know, the examples like the ones Chris was talking about are pretty rare, historically, you know, obviously, a lot of countries have promoted, I mean, historically, the most significant thing that people tend to do is try and promote population growth, because more people equals bigger armies. And, you know, but we don't really do that anymore. It's considered to be something that, you know, is best left to individuals to decide. But suppose that we were going to try and design an ideal level of the population? Well, so this is a problem that so the Aleph Insights official philosopher, who is Derek Parfit, who we covered, we did cover on one of our early podcasts, actually, because he just we did a sort of obituary roundup of Derek Parfit. In his book, Reasons and Persons, he devotes a chapter, really a whole whole kind of chunk of the book to thinking about future generations and non existent people and the extent to which they ought to be considered. Now, you might say, what have non existent people ever done for us? Who cares? But the the thing is that the there is lots of times where we think about non existent people. And there's a kind of one of his first thought experiments is about pregnant mother, who currently has a temporary illness. But if she has a simple treatment, if she sorry, unless she undergoes a simple treatment for it, her child will have some sort of congenital disorder, just medically plausible. But if she has the treatment, the child will be fine. Compared to a woman suffers from an illness who, if she if she has a baby, now she gets pregnant. Now, her child will have the congenital illness. But if she does it in six months time, she'll have a completely normal, healthy child. And you might think, well, the obvious thing to do there in both cases is to either have the treatment or wait it out be much better to wait six months and have a child who's going to be healthy and not. But the what Parfitt's point here is, in example, be it's a different child, what we're saying is that the first child is better for that child who would have been born, but with the congenital illness to not have been born at all. Right now, so we do make decisions, we make decisions where we compare non existence, and, and existence with a certain level of welfare. And the fact that we do make those kinds of we can make judgments about that shows that we do, we are capable of thinking about the idea of there being value in non existent people, whether it's positive or negative. So that that's the kind of question really is what value do non existent people have? Or let's imagine that we had, we could snap our fingers and make it the case that there's there'll be a billion more people in a year's time. And that those billion more people will be broadly happy, right? Should we do that? Would it be better to have more people, even if let's say the average level of happiness was a bit lower across the board? But where, you know, the, the total amount of happiness was higher? That that's, that's the key question here, you know, is, and we do have concern for future generations, we worry about their welfare, you know, we think about the environment and our legacy for the future. But anyway, Parfit, essentially, he doesn't really come to a theory, he says, he got, I think he says, it's like theory x, that there isn't really a way of answering this, which, which is satisfying. And there's a very good paradox, which I can explain, if you like, called the mere addition paradox, which essentially says that all our intuitions lead to a conclusion that is would be really bad. Do you want to hear it? Go on, then? Yeah. So imagine a world where there's 100 super happy people, right? Yeah. Now what you can, if you want, create another 100 people on the other side of the world, who are 80% as happy as the super happy people, right? Is that better or worse? Is that a better world than a world where there's just 100 super happy people got 100 super happy people, or 180 people where 100, sorry, 200 people, where 100 are super happy
Speaker B:and 100 are pretty much super happy? I think, I think, for me, the the answer depends on whether you, whether you include suffering, right, and where suffering begins, and on and not being
Speaker C:happy ends, right? You let's, you have to assume for the purposes of this paradox, that these people are very happy to be alive, not quite as happy as the bliss people, but they are still very, very happy to be alive. And they're having a great life. And they enjoy themselves. And then they die. That is that better to have those people in the world or not? But hold on. Also, I think,
Speaker A:presumably, an extension of this would be what about 60? What about 50? What about 40? Right?
Speaker B:Well, that's where we're going. So there's the other element, which is just built into human nature, which is the 80% of people, or rather, the 100 people who are 80% as happy as the 100% happy people are going to become distinctly less happy when they realize there are some people on
Speaker C:the other side of the world who are 100%. Maybe, maybe, maybe. Let's assume that the 80% factors that in. So the fact that they're 80% as happy, it already includes some dissatisfaction, right?
Speaker B:They were 90% as happy, but then they found out.
Speaker C:Anyway, the point is that your intuition is supposed to say, well, that that is obviously better. It's obviously better to have a bunch of happy people alive than not existing. I mean, you know, obviously, otherwise, we might be saying it would be better to stop someone existing who was alive and happy, for some reason. And then and then part of it goes, Okay, well, if you're happy with those, what about what about the next situation where we have 200 people, so pretty much the same as before. But this time, they're all as happy as each other. And they're 99% as happy as the as the original people, right? So now we, we, we, so the total number, the average happiness is higher than it was in the previous example, right? Fair enough. We've lost a few people who got that last 1%. But that we've more than compensated for that with the other people. And, and if you as most people do go, well, intuitively, yes, that sounds better than the second case, like we've moved in a direction, which, which is making making things better.
Speaker B:Then he's got you. Parfait's got you in a trap. So what you're saying is basically we made 100
Speaker C:people unhappy. Well, in the second situation. It's worse than that. So this is why it's called the Repugnant Conclusion. Because because taken to the extreme, what you do is you keep adding people in blocks of 100, and making them ever so slightly less happy. And every single time, you have to accept that you're improving the situation according to this, to this sort of intuition, until you have a situation where the whole entire earth is full of billions of people who are only just slightly happier than being dead. And that's the Repugnant Conclusion. And, and it isn't resolved. You know, there isn't a resolution to this. Some people embrace it. And they say, yes, strict utilitarians say, yes, we should, we should just keep having more people, more people is good. And, and it doesn't, you know, a world in which there's billions and billions of people, but they're all, you know, only just happier than not at all, is good. Whereas other people, other people were, you know, have sort of tried to challenge the idea of measuring welfare like that in the first place. And, you know, but I think I mean, it's something that it's a really, really interesting argument. I feel very challenging for this kind of policy discussion, because, you know, is the right answer. Do we want more people for their sake,
Speaker A:let alone our own? Well, as is sometimes the case, it all feels a bit bleak. And unfortunately, the person I want to go to next usually makes things bleaker. So we, we, we need to finish. Chris, anything that we've not said yet that you want to come?
Speaker B:Yeah, well, so I'm gonna, I'm gonna put a little ray of sunshine in, in, in there just to I'll believe that when I hear it. One day we'll all be dead anyway. Exactly. No, no, I was gonna say that, you know, I, I think that I think there are two reasons for hope. One is this idea that I think we are self, we are self calibrating. And I think it's largely accepted that, that at the moment, the extent to which we, we consume resources, and the size of the population, and certainly the size of the projected population is becoming difficult to sustain, right. And without without that happiness going down quite a lot, right. So I think there's an element where we actually do want to think about, you know, if consumption is a source of happiness, but over consumption is a source of misery, there's, there's a point at which we want to say, well, maybe there is an optimum population then. And it's where that sort of balanced where you can, you can have what you want. But it doesn't, it doesn't have negative repercussions that cause misery elsewhere or net misery. Demographic Macawberism. Exactly. So I think if we, you know, as we go forward, I think the fact that we're starting to reduce our population, or at least our growth rate is probably a positive thing. And the, so I think that's, that's good. And I think the other thing that I will throw in there is that, you know, we're not going to even though I constantly refrain about the, the hard work of children, and, and the fact that sometimes they might be a net, not quite a net source of misery, but there's a lot of misery, balanced by a lot of pleasure, right, and a lot of, a lot of good things. And so I don't think we will, we, we can give up that, that process. I think it is beyond human nature to not reproduce at all. Now it might reproduce at a rate, which leads to population decline, but reproduction itself, I think, is unlikely to disappear. I think it's so fundamental within our genetics, you know, all the sort of Dawkins type stuff that, that it's here to stay.
Speaker A:Those eggs will find another way of making, yeah, an egg. Exactly. Yeah. So just to finish us off, quick question. If you could live in a world, if you could choose, would you rather live in a world with 100,000 people, or in a world with 100 billion people? Let's start off with Chris, what are your thoughts? What do you reckon?
Speaker B:Well, yeah, so I mean, obviously, they're two massive extremes, right? But so the question, the crux of the matter is, would we rather have underpopulation or overpopulation, right? But you know, it's a bit like saying, would you rather boil to death or freeze to death? You know, But bear in mind, at one point in Earth's history, we did have 100,000. Yeah, we did have 100,000. But it was pretty darn miserable then, I suspect, you know, but assuming that, you know, regardless of how we got there, right, assuming we maintain modern technology, right, so it hasn't been as a result of, you know, us being thrown back to the Dark Ages and vast swathes of people being wiped out. So let's just ignore that bit, and say we can have 100,000 people or 100 billion people, I think I would go for the smaller, the smaller number, so long as we would concentrate, I would find it very bleak, unpopulated world, you know, just everything like Siberia would be quite depressing. But it doesn't have to be like Siberia. Yeah, yeah. But my misanthropic nature means I just could not cope with 100 billion people. It's bad enough, to be honest with you three. Or two. Nick?
Speaker C:Yeah, well, I'm gonna go with the sort of global, one of the things I quite like about Star Wars, the prequels is Coruscant. I really like the idea of a planet.
Speaker A:What's Coruscant? I can't remember.
Speaker C:It's the capital of the Galactic Federation. It's just a giant planet. Yeah, it's basically one big city. It's just one big city. I think there is, I love cities, as I'm sure I've brought on about in previous podcasts. I find them much more interesting than the countryside, right? I mean, you can get lost in them, they have far more geography and detail. And, you know, when you get cities that are big and old, and they grow up in layers, and there are sort of hidden things behind other things. I love all that. So I would go with 100 billion. And I think, you know, we would, the technological progress would be, assuming we can have that keep pace, and in fact, accelerate. You know, I think 100 billion people would give us a real, that really would give us a good incentive to get off this planet and start colonizing, you know, the rest of the universe, as you mentioned. So I sort of feel like, well, you know, one day, there might be 100 billion people, maybe not on Earth, but there might be 100 billion people dotted around. I would love to see that, see what it was like.
Speaker B:I reckon it's more likely we'll have 100,000. But there we go.
Speaker C: hould make a bet. Pays off in: Speaker A:Okay. Nice. Right. Let's finish off there. Thank you, as always, for listening to the Cognitive Engineering Podcast. I'm Fraser McGruer. We've been here with Chris Wragg and Nick Hare of Aleph Insights. Until next time, goodbye.
