#44 - Dean Spears - Population Decline Is Worse Than You Think

32:41He was sure wrong about everything. That's what I can hope for. I guess it's a good outcome if that's the case. But yeah, it's a form of false zero-sum thinking, which can be incredibly damaging. Because if you make policies based on the fact that, oh, this is a completely fixed pie and there's nothing we can do and we can only divide it up. and you're just neglecting all the sort of frankly known unknowns but even unknown unknowns that can come through human innovation then that's when you end up in these really dark places I think quite regularly and actually you made a point when I was reading through your book that I had not considered before which is really cool that made me like grok this idea of actually more humans are better for example with something like climate change yes okay we're currently producing more carbon but at some point we're going to reach this peak and then it's completely decoupled and we're going to have so then it doesn't matter if we have more humans because the energy they're using is not contributing to climate change but if we have fewer humans we still have this like surplus of carbon in the atmosphere right we've got to do something about that and if now our population especially like the sort of okay like scientific research population which is arguably one of the biggest demographics that is reducing, the people who are likely going to be inventing carbon sequestration technologies and all of these other ways to try and draw down this excess carbon, they're not having babies.

34:12There's fewer people to actually try and find the solutions to get rid of this surplus. So that was like a really good point that I feel like people would like. Or just to manufacture the machines or plant the trees or split up the rocks for the weatherization process. Because I don't think this is the first paragraph of what to say about population and the climate, but I think it is important that one day we're going to have a big negative emissions problem that will have reached zero per person net emissions, and then we have the negative emissions problem of needing to suck the carbon back out of the atmosphere.

34:51And so what do you think is, what's going to do a better job at that, right? A bigger or smaller world economy. It's sort of funny. This is one of these things that we discovered by accident. We were doing, we'd taken the Nordhaus climate economy model that he got the Nobel Prize for and we're sort of, you know, he sort of takes population as just an input to his model, right? And so we were saying in that model, what if we vary the path of the population? you know, then how much of a difference does it make to climate change? And it's like peak temperatures. And the answer is not very much. But we sort of discovered by accident.

35:30And I sort of like, I first thought that like the postdoc research scientists on our team had made a mistake. We're like, you know, Kevin, go back and look at this again. But like, in fact, the larger population ultimately leads to lower temperatures in the long run. And it's because the model did allow for these negative emissions where, you know, a larger economy that's doing more can plant more trees, split up more rocks, whatever it is. And so exactly, so it can just exactly go the other way. Right. And another point you made was that certain big risks that we might face or problems are very much a fixed cost.

36:03So, okay, I don't think asteroids are likely to be happening anytime soon. But let's say an asteroid was coming to Earth, which population size is more likely to actually deal with it? 10 billion people or 1 billion? Like given it's going to cost, let's say, 10 trillion or some huge proportion of GDP. And again, like that sort of made me go, huh, okay, we do actually need more people there. One objection I often hear though to this idea of, okay, well, sure, the population is going to decline, but aren't we moving into the age of AIs, even AGIs and automation robots? Can't they just fill the shortfall?

36:45Yeah. I mean, so, you know, there are people here who know more about that than I do. But, you know, I think nobody knows everything about what's going, what AI is going to bring. I mean, there are some economists like Eric Brynjolfsson, who think that maybe we're going to see like a 7 % improvement to GDP or something like that. There are some like Daron Asimoglu, who would say like, you know, a 1 % or something like that. I mean, you know, nobody really knows. But I guess the question is like what is ai going to do to the marginal product of humans right like if we're so i mean we sort of haven't gotten into it but like like just to sort of so we're sort of you know part of what we're saying in this book is that other people are as you say win-win um that you know their lives are good for them and their lives are good for you we're we're made better off by being in a world with other people in it.

37:39And, you know, there are a number of reasons for that. One is that when other people want and need the same things that you want and need, they make it more likely that you'll get it. You know, where are you going to find, you know, an event like this and a space like this? Are you going to find it in a city with other people in it or in a depopulated rural place? Well, of course, you're going to find it in a city with other people in it, right? Other people make it possible for the things that you want to happen. But another part of the case for people is, as you say, that people create things, people invent things, people discover things and realize things.

38:16You know, why do we have better lives, longer lives, glasses and antibiotic pills and vaccines and microphones that people a few hundred years ago didn't? It's because of the knowledge that the people over those couple hundred years have developed. And, you know, one person learns an idea and other people can learn it and build on it. You have a kid, a sick kid with an infection. You give them an antibiotic pill. That antibiotic pill is gone and used up forever. But the formula of it is still there for somebody else to use again. And even more than that, the knowledge of the germ theory of disease and the basic understanding of what it's all about is still there for other people to use and innovate and build on.

39:03And so that's called the theory of endogenous growth. And it's an important part of how macroeconomists understand why our living standards are higher than in the past. And what's the core thing there is that we're better off because of what other people have learned. Okay, great. So that's part of the case for people. And then Liv comes along and says, but what if we're not going to need people anymore, right? What if AI does all of that thinking and learning for us? And so it's true. I mean, the first thing to respond is there's at least some important probability that we're going to be in a world where we need people to be doing important things for a long time.

39:50And so you can scale everything I'm saying by that probability. And, you know, that's the cheapest answer. But, you know, there's a more sophisticated answer, which is that, you know, for this sort of discovering things work that people do, you know, AI might turn out to be a substitute for humans, or AI might turn out to be a complement for humans and increase the productivity of other people. Lots of other technologies have been have been complements for humans, right? So when spinning yarn was mechanized, right, that was a substitute for what humans did. Nobody did that work anymore, right?

40:29But when, but when, you know, factories themselves were powered by water came online, that was a complement for human productivity and made humans more productive. So, you know, one possibility is that new technologies will be a complement for what humans learn and discover, in which case the case for people will be all the stronger. Now, I'm a demographer. I don't know which of those is what's going to happen, but I just want us to raise the possibility, quite possibly, AI not only leaves space for humans to continue to contribute to progress, but actually makes humans more productive. Plus also it would be very sad if again like we are missing current projections in I think is it 50 years time they'll be about a third of us or two-thirds of us a third of us won't be here or imagine your family people and it's nice I would rather be friends with humans than robots I'm sure the robots are gonna be great but or both but I mean yeah I mean I guess the question is how many how many robots make up for one human Now we're getting into the utilitarian.

41:38Well, right. So part of the case for also, you know, I said part of the case for people is that they want to need things and sort of they economically demand things. Right. Like you want there to be other kids who like if you're like a parent, you need there to be other parents that your kid can have a school. All right. And like you need other people to to need the things you need. You know, when my mom was sick with a rare form of cancer where we lived in Oklahoma, there wasn't, you know, well, first of all, only 640 people that ever had that cancer since the 1970s. So nobody knew anything about it.

42:16But even in order to learn that, we had to drive to a big city where there was a hospital where there would be a doctor who would even sort of know that fact, right? If what you need is specialized treatment, you need other people who need that. If what you need is a kindergarten, you need other people who need that, right? And the AI isn't going to do that same wanting and needing for us. And so that's another thing that we might need other people for. And finally, as you say, part of the case for people is that they make us better off. But we're here to talk about win-win. And part of the case for people is that we might think that there's value in people getting to live good lives.

42:55Definitely. So what are, in your views, the best strategies to try and get people all over the world, but especially in the countries where the rates are at their most lowest and the problem is most drastic, to actually get them to start having more babies? So in case you've been waiting, I'll disappoint you right now. I don't have the solution with a capital S. I don't think anybody does yet. I think it would sort of be preliminary, I think, to be saying, here's my legislative proposal or something, because we're not yet in a world where there's even much of anything like a consensus that stabilizing the population would be better than depopulation.

43:42We're raising the question, and frankly, what we're trying to do is say, you can be a person who cares about environmental stewardship, who cares about reproductive freedom, who cares about gender equity, who cares about all sorts of priorities, and also care about birth rates and the size of the future population. That we're trying to bring more people and more voices into this conversation so that maybe someday more of us will think that, you know, we shouldn't just accept depopulation as the default and that stabilization might be a better future. But, you know, when I but I'm not like hopeless about thinking that we don't have the answer because I sort of think about that we're, you know, the UN projects the size of the population to peak in 2084, six decades from now.

44:40right maybe it'll be that maybe it won't but you know six decades ago was the 1960s when there was you know first starting to be some policy attention to climate change as a problem so you know Johnson gave a speech to Congress about burning fossil fuels and and you know that wasn't the beginning of people collecting data on it like Arrhenius had done like atmospheric chemistry calculations that were pretty close to true even before then but I think there is something notable about what what people were thinking and talking about six decades ago. And six decades ago, if at the beginning of the climate policy conversation, somebody had just stood up and sort of spouted off whatever policy prescription happened to come to their mind, it probably would have been ridiculous.

45:23It wouldn't have been fact-based. And it would have driven people away, right, saying, like, we're going to get rid of the internal combustion engine in 1965 would have made you political enemies. But it's good that people were talking about the challenges of climate change back then, even though we didn't yet have the journal Nature Climate Change or college majors in it or all of the technology and knowledge and social movements and political movements that we have now. Now, it's good that people were talking about climate change back then six decades ago, because it's because they were talking about it back then that we know so much more now.

46:00And so the hope that I see is that we're starting a conversation now, several decades before the size of the world population is projected to peak. And more people are going to learn and talk about this between now and then, learn the facts, start thinking about what might be different. And then it does, I think, go back to what you were saying about social influence can be win-win or it can be lose-lose. You know, none of us is born with like an ideal fertility rate imprinted into our DNA somewhere, right? That's something that develops over the course of a life and changes over the course of a lifetime for that matter.

46:47It depends on what we see other people succeeding with, what we see other people rejecting. It depends on the world around us. It depends on what we make easy for people. So, you know, if we were to, as a society, come to decide that stabilizing the population would be better than depopulation and that we were going to find a path to that that perfectly preserved people's freedom to choose to parent or not to parent, two on average doesn't mean two for everybody. But if we were to sort of make the investments that supported people who did want to choose for parents in a really big way, right? I'm not talking about like a$5 ,000 child tax credit.

47:28I mean, how many of you would marry somebody different for$5 ,000, right? I mean, like that's not the amount of money that's going to move people's family formation decisions. But if we were in, well, I see a hand raised over there, but if we were in a really big way going to invest in taking better care of our caregivers, doing more to share the work of making the next generations, dads doing more to share the work of making the next generation, then maybe we would see more people feeling like they could fit that in to the life and goals and education and work that they want. And probably not immediately, but maybe the next generation after that would learn from that example and the next generation after that would learn from that example.

48:09And then maybe people would start wanting something different. But it's not going to be turnkey in any way. And I think it starts from a broader recognition that maybe stabilization would be better than depopulation. well in the sort of spirit of getting more voices in and I know that there's a lot of burning questions uh let's open this up um feel free I mean from my end I would love this to be as much an exploration on like what we can do um to try and solve this but if any of you have objections or further questions that I haven't touched on then then use that Adrian was first so I may have missed something but if I gather correctly since population has been declining for um as long as we've been keeping records?

48:54Birth rates have been, right? Birth rates. Does that mean that modern birth control hasn't really had an effect on birth rates? That's a great question about contraception, right? So no doubt contraception is very important in people's lives. Not having contraception is bad for people's lives, especially about, everyone should have the opportunity to choose whether to be pregnant, not to be pregnant, not to be pregnant right now, to wait for another time. And, you know, having access to contraception and abortion, you know, to let people make the decisions in their lives and decide when to be pregnant, that's very important.

49:32And it's a further social scientific question whether the decline in birth rates can be accounted for by the spread of modern contraception. And just as you say, We see birth rates falling and people controlling their fertility in other ways, you know, spacing and timing before the existence of modern contraception. And we also see birth rates continue to fall in places that have had access to modern contraception. So, you know, Sweden happens to be at the top of my mind. About a decade ago, it had an average birth rate of 1.8. I think now it's maybe like 1.5. That's not because hormonal contraception and other modern methods only came to Sweden 10 years ago or something like that.

50:25So it doesn't explain the continued fall that we're seeing from a number like 1.8 to a number like 1.4. So, yes, people should have the health care that they need of whatever form, including that. But I don't think that that's really the statistical, that that really fits the facts. Do you see a spike when modern birth control was introduced? I don't exactly know. I mean, I can give an example of like in Romania in the 1970s with Ceausescu's decree 770, contraception and abortion access were suddenly banned and removed overnight. And so like you're talking about a spike made me think of that because you do see a big spike in birth rates right when that happens.

51:13But then what you see is over the next decade or so, birth rates continuing to fall, you know, more or less at the same rate that they were falling in other sort of middle income countries. And so showing that, you know, people were making decisions, you know, making family formation decisions of other forms, you know, using, you know, other methods. And so, yes. So what does that tell us? I think it tells us that if you surprise people by taking away a method that they thought they're going to have access to, that could be suddenly really destructive. And then in the long term, populations are on average able to pursue what people want.

52:09Now, that doesn't mean that everybody gets the parenting life that they want. Far from it, on average. Nobody gets the exact parenting life that they want. But you do see that, on average, there's a pretty clear correlation between the average number of kids that people want in a society and the average number of kids that people have in a society. It's not perfect. The lines cross one another, right? It's not like exactly tracking the 45 degree line. And, you know, the deviations are really interesting and fill interesting journal articles. But like the R squared, the correlation is pretty high.

52:49Like, you know, at the population level, what societies get tends to be pretty close to at the population level, what societies want. cool um yeah i've read the studies around desegregation of all the causal factors around urbanization contraception education all those things contributing in different ways my question is are there subpopulations in india or in other urbanized economies that are modern that are going the other direction where they've not only where they've been able to sustain at least population stability, if not population increases? And what have those subpopulations or subpolicies or anything else done differently than those around them?

53:34That's a great question. And we get this question enough that a couple of years ago, we put a paper in the journal Demography about can high birth rate subpopulations cause positive long-term population growth and like the answer is like it's mathematically possible but it you know empirically depends on a couple things being true right so the the high birthrate subpopulation has to stay high in the sense of above to generation after generation after generation right and so The answer to your question for India is you can split India into 16 different groups, Hindu, Muslim, rural, urban, educated, not educated, whatever.

54:24You get all 16 lines. Some are higher and some are lower, but all 16 lines are going down. They're not all below two yet. People in India, like Hindu politicians in India used to say, oh, Muslims have more babies than Hindus do. right and Muslims do have more babies than Hindus do but it's gone down for Muslims and it's gone down for Hindus and so if even high birth rate places are above two you know like Utah for example is like every other state below replacement is it okay like Hasidic Jews in Brooklyn and Mormons are the two that came to mind in the US yeah so I mean the Mormon birth rates around five right now and it used to be higher than five and you know so we get the question of Mormons a lot Right.

55:07And so, you know, you know, at the simplest answer, the birth rate amongst Mormons and Amish. I'm sorry. I apologize to anyone listening to this.

55:22I actually don't know the I don't know if there is an estimate of the birth rate amongst Mormons. Does anybody know that? Like I read somewhere I was around four ish. I heard it has decreased heavily to 2.something again, but I'm not sure. I thought Amish are the only group in the U.S. that is still managing to stay above 4. So Amish is higher than average, but also falling. Right. It used to be over 6. Now it's at 4 level or something. So, I mean, the example that I like to talk about is the Catholics of Quebec in Canada. This is exactly what I was looking for. Really? um because there's like super niche i would never know this yeah because um my my co-author mike uh his mom grew up speaking french and you know descended from the the the you know quebecoise catholics um and you know where sib ships were numbers like 10 or 12 right in the mid 20th century um and um so not that long ago right um but you know we're not having this conversation in french with a quebec accent right the quebecoise catholics have not taken over the world um and that's because birth rates there fell um you know mike um has one brother um and you know so on.

56:54So I think it's easy to have like survivor bias or hindsight bias and talk about the subpopulations that we know about. But there are other subpopulations like this that anybody would have picked out as a candidate for, you know, this is going to take over the world that have then not done so because birth rates have fallen. And so it's not enough for your birth rate to stay high if what high turns out to mean is 1.9 instead of 1.5 that wouldn't cause positive long-term population growth so so no there really aren't yeah yeah actually that's I was gonna say my hot take as a as a woman but not just a woman but a career woman I actually do feel like it's the industrial revolution as one of the causes, but not for the reasons cited.

57:54From my perspective, I actually feel like there's this perceived dichotomy for many women that I've spoken to, where either you get to have a fulfilling career or you get to have children, have a vocation or have children. But I just feel like our ancestors simply did not have this perceived dichotomy. Pre-industrial life, everyone contributed. And the concept that we now have, the nine to five career, only really existed after the invention of the assembly line. And so pre-industrial revolution, you know, we didn't live that way. Everyone, all hands on deck on the farm, whatever. You had a store, your kids came in, they helped greet customers, right?

58:36So our education systems and workforces, they still model this assembly line model, this nine to five model, especially with AI. Do we need that anymore? and so I feel like that's largely not conducive to family systems and it's funny that you brought up South Korea because I spoke to a diplomatic delegation from Japan and South Korea of women in STEM and they couldn't even fat most of them couldn't even fathom the concept of having children in the workforce and then one person in the room I forget like which country she was from but she was talking about during the pandemic they did and it kind of changed everything for her so I actually you know I wonder if we could just change the model for how we integrate children into our lives post AI post industrial revolution and like just thinking about it in a way where to like cite win-win it's like why why give up career why why because you hear a lot there there really is just on the media as a woman this perceived concept that either you're a stay-at-home mom or you're this career woman well why not both yeah I mean I'll say you know on the question of being a stay-at-home mom or working I mean let's also point out that dads can do more and maybe that'll be part of the answer to but hi the question I had was kind of focused on some of the two core costs of population decline that I see that you didn't touch on.

1:00:11I'm curious. I imagine they've occurred to you, but maybe there's a reason not to bring them to attention. But I agree with your key point around like there's not yet a general cultural consensus that population decline is a problem and like maybe stabilization is a better idea. Some frames that I've found particularly powerful is that the Social Security Administration was introduced in order to try to take care of elderly people who are in desperate poverty. We don't want elderly people to be starving to death and horribly neglected medically or financially. And we've been able to support elderly people in our civilization when we have a handful of working people who are able to support each elderly person.

1:00:56I don't know what the number is right now. Maybe it's three or four working age people for every elderly person who's retired. I think it was about nine months ago that I asked ChatGPT to help me do the math. If we extrapolated forward the birth rate of the United States today for a number of decades, I think it's 1.7, 1.8, something like that. what would need to change in terms of the tax burden on working people in order to keep stable the support that retired people received? Or on the flip side, if the tax burden as a percentage of income did not change, how much would their support reduce over time?

1:01:34The numbers were pretty brutal after 50 years, which I'm sure you're familiar with. So that's like number one, do we want elderly people not to be in desperate poverty. And I think there's also a significant challenge around, like, do we get to keep having democracy if there's four elderly retired people for every working age person? Because it's not clear to me that that's true. If the elderly population that votes at higher rates keeps voting for more and more money to be extracted from the working age population in order to make sure that they maintain a decent lifestyle, I don't know that we get to keep having democracy.

1:02:11So I think those for me are some of the harder hitting points around like, whatever your perspective around climate change is, whatever your aesthetics around whether humans are good or bad for the planet, if you want elderly people not to be in desperate poverty, and you want to keep democracy, we probably need to stabilize the population. So those are hard hitting points for me. I imagine you've come across them. I'm kind of curious what your perspective on is. Is that a good meme to spread or is that maybe a bit too confronting perhaps? No, no. In fact, I'll say you sort of anticipated my semi-interesting thing.

1:02:52You took my bit about age and voting. No, no, I'm just kidding. But yeah, so you're right. If somebody told you, an economics professor, was going to be sitting around talking about low birth rates, then you would probably assume the conversation is going to be about the age pyramid of society and government budgets and things like that, because that's what you hear about the most. And I think like the main reason that Mike and I don't talk about that much in After the Spike is that it is something that you're sort of hearing from other places. Um, um, you know, we think that this, that these other really big parts of the case for people, um, you know, about, um, about progress, about, um, you know, other people making things possible when they want it.

1:03:40And yes, about the, the value in getting to live a good life. You know, we think those are sort of under emphasized by comparison. Um, so that's a big part of why we talk about it. But yes, I think you're right that one of the... Okay, you know, so the median age in the US population in 1950, I think was 29. and in 75 years since then has increased by nine age years to 38 and is projected over the next 75 years over an equal span to increase by seven age years to 45. So the increase in the median age in the U.S. that's coming is actually smaller than the increase in the median age in the U.S. that, you know, for better or worse, one way or another, by hook or by crook, has gotten us here.

1:04:37But one of the things that, so make of that as you will, but as you say, I think it will shift voting patterns. And so back on the question of environmentalism, and when we know that younger voters tend to be more environmentalists than older voters, and so, you know, that's one thing that might shift as the age structure, population changes. We should expect voting patterns to shift with it. Now, is that the meme that's going to get people interested in learning these facts and talking about this question? Your guess is as good as mine on that. Are there structural or economic incentives that have proven effective in increasing birth rates?

1:05:23Yeah, I mean, I think not really, right? That can be a short answer. Not in terms of long-term lifetime birth rates, right? So if you offer somebody, you know, let's just say that I were to go and give you$5 ,000 if you become a parent in the next three years, right? You might do it, but then not have a kid that you were otherwise planning to have six years from now. And so I've accelerated when you have a kid, but I haven't changed your lifetime average number of births. And so we call that like the tempo versus the quantum of fertility. And that's something that makes it really hard to study and learn like from the effects, you know, you can do your fancy statistical study of an effective policy on birth rates, but are you just studying the tempo or the timing of when people have their births?

1:06:21Are you studying the lifetime differences in birth rates? And I think when you study the lifetime differences in birth rates, it's really hard to find lasting effects. Like remember the thing I said earlier, would you marry someone different for$5 ,000? So I think that like what really matters, what really influences me is bigger picture evidence like, you know, university is free in Canada and the birth rate is lower, right? You know, things like that in terms of nothing, you know, even countries that think they have policies haven't brought us up to two and and here's this one in so this thing that matters the completed cohort fertility how many kids you have on average over your whole your whole adulthood right so you have to be a relatively rich country with good statistics to even be able to compute that as opposed to like a cross-sectional survey but for the places where we can compute that there have been 26 countries where since the mid-20th century we've seen completed cohort fertility fall below 1.9 right and in lots of those are places where countries think they have policies to increase birth rates or and lots of them are places that have social safety nets and all these policies they were talking about and some of these are places that don't but of those 26 that have ever had completed cohort fertility fall below 1.9 zero of them has it ever gone back up to two and so you know that doesn't mean that it's impossible, but it means that there's not a precedent that we can draw on.

1:07:49I have so many questions. No, the first question I have is kind of like the academic. Has anybody ever studied, we always talk about infant mortality, but what about the probability of getting a kid to 18? So in Lincoln's time, death was rampant, right? A lot of people, maybe they survived childbirth, but it didn't make it to 18. And perhaps has there been any study or has it been embedded kind of in the hive mind that I need to have five kids to get two kids to 18? You know, go further back. I need 12 kids to get two kids to 18 or to get three kids to 18 and out on their own. Has there been any data or study on that as opposed to just the infant mortality part?

1:08:33Yeah, absolutely. So like sort of pre-adult mortality. And so like there's a paper by Stuart Gitalvast and co-authors that sort of goes through for states of India and computes just this number you're saying of like, well, because, you know, in a in a state where the the pre-adult mortality rate is higher, the replacement birth rate would be higher. And so the replacement birth rate might be a number closer to two for a state in the south like Kerala, but closer to three for a state in the north like Uttar Pradesh where pre-adult mortality is greater. So, yeah, absolutely. That's a great question.

1:09:11And then I'm not yet on the camp of stabilizing population is a good thing. And I want to stay on one vertical to not like dominate. I want to push back on the AI and embodied intelligence because we talked about it being more productive. the ability to enhance humans in order to create and do things doesn't mean we we can get by with less humans maybe a population of 1950 or 1980 like we're talking about trying to change people have run the experiment and people said my quality of life is better with two kids or less and you know i tell people one kid's an accessory two is a circus right and so and i'm a parent right like if you have one kid it's an accessory you can get by you can do anything you have two it's a circus and then three, it starts to get crazy, right?

1:09:58And I think hidden in the data is people's choices that I have a better life, a more fulfilling life with less kids. And here we are trying to talk about, hey, for the good of my neighbor or some other out there, you want me to have a less fulfilling life by having more kids. I mean, it's just like kind of smacking us right in the face. Well, that's not what I'm saying. So I need to jump in. Okay. I don't think that anybody is making necessarily a mistake if they look around the world that we have and decide that not being a parent or not having a kid isn't the right decision. What I am suggesting is that we might all be making a mistake as a society if we're not choosing to build the structures and make the investments that would allow and support more people who want to be parents to choose to do so.

1:10:50It's a very different question. I think that we can agree that parenting should always be a free choice, and that doesn't specify everything about a society. So the law says that parenting is a free choice, abortion is legal, and contraception is legal in France. And the law says that parenting is a free choice, and abortion is legal, and contraception is legal in South Korea. but the birth rate in France is more than twice what it is in South Korea because there are other things that matter for the decisions that people make for their lives what they aspire to and what they feel like they can achieve and so this exactly isn't me or I mean I don't know what I mean or saying that that you know that individuals are making the wrong decision it's me saying we should be starting a conversation about what sort of of equilibrium we might want to build towards you know over the years or decades and that maybe that's one where we want to do more to share the burdens of costs of creating the next generation do more to to make it easier for people do more to pitch in and help so that it's not all landing on the few years in working age adulthood where you're parenting and having your young kids at the same time.

1:12:22That's the question that I think we should be talking about. That presupposes the new tools and AI don't augment and fill the gap of less humans. How do we know that? It's easier. How do we know that a million robots are only equivalent to four billion humans? Okay. So this brings us back to that part of the case for people is the case from the endogenous growth macroeconomics that growth and improvements in living standards come from improvements in technology, which have generally come from discoveries from other people. Now, one question you're raising is maybe we don't need people to do that anymore.

1:13:03I mean, you know, maybe yes, maybe no, maybe AI will be a substitute for human innovation. Maybe AI will be a complement for human innovation. Maybe AI will free people up from doing that work so that people end up doing something else productive for one another. And we still need people, but to do something else. I think all of those things are possible. And even if I knew for sure that we didn't need people to be doing the innovation, I would still think that there would be an important case for people. Part of it is what I said is the other people wanting and needing things, that people are good for you even when they're on the demand side of the economy.

1:13:45But I think another part of it is that this invites the question of does it matter how many people get to live a good life? you know if you know what what a lot of people don't talk about when we're talking about this is that you know one path is a path where many billions of additional lives could get to be lived that could be really good and wonderful and valuable and full of happy experiences for the people who live them and so one question we should ask is would the absence of those lives be you know would it be a nothing would it be something to celebrate or would it be a loss to mourn because of those experiences in it and you know I I don't expect that I'm going to change anybody's mind on this question or settle it right now but um you know to give my answer I would say that I think that you know more good is better and that that includes the good of getting to live a good life and have good and happy experiences.

1:14:48And that it does matter that, you know, if people don't get to live those lives now, to say yet again, the fact that something matters doesn't mean that it's the only thing that matters. And it doesn't mean that we should, you know, take away people's choice or impose it on anybody. But when we're thinking about which path should we build towards over the long run, perhaps one of the things that we should be asking is, is it better if more people get to live and experience good lives rather than fewer? Now, I suppose you could come back and say, maybe AI is going to have good experiences and do all of the enjoying for us.

1:15:24I would just say that the next sum total of fulfilling lives would be higher with AI and less people than with more people. But you can't go there forever, right because like what if you have one person and infinite ai no i i say so there is some something where it's still better and somewhere where it's not you know i'm nobody i'm nobody but i would say stabilizing at 10 billion is not the optimal point you have this is important let's talk about this right because i'm also not saying that we should stabilize at 10 billion nor am i saying we should stabilize at 8 billion or 6 billion or any other number right i don't think that anybody knows or could know the number that we should stabilize at.

1:16:05I think that would be sort of beyond what we could hope to know. But here's what I think is fascinating. If you think that we should stabilize the size of the population at some level someday, then you're on the team of needing to find a good path to an average birth rate of two, needing to raise the birth rate at that someday up to two because stabilizing the population at any level even a level much smaller than today will someday require an average birth rate of two and that's something we don't know how to do. If we had fewer people what would that actually mean? Like if you look at a family photo and you have currently five people in that family photo that family photo would have had only three or four people.

1:16:49Is that something you actually feel as happy about having had as a family photo as the one where you had five people in and i think that the answer for most of us is not if this room in south korea where if we were in south korea with this room in two generations we'd be one seventh of our age-like people it's like sure we might arrange ourselves differently whether we are still finding like ways to be 30 of us there are fewer groups coming together talking about fewer various things that seems pretty bad so like in i that's just on the other side of the equation i'm not sure where it ends up but like that's something to consider usually we like the people around us and the more people we have the kind of like more fits and better friends we can also find and better partners you know the whole like is there someone for everybody well not if there's only like a very few people then they're like some very good ones some very bad ones what if the hive mind of the world has already solved for the optimal number and that's why birth rates keep going down no so so maybe but i think and so and that's what i wanted to get to is when you said this point about the thought experiment, I actually wasn't initially into the thought experiment about pressing the button to make the baby because I thought the obvious answer is like, well, I often wake up with a hangover and a baby.

1:18:05Very, very frequently, in fact. Or if Liv tells me, oh man, should we? The baby is not just a button, right? Exactly, no, but that's exactly, I think, what would happen because that is what we also see with policy in countries when they enact something, right? It initially has an effect and then it falls back down to what it was. So I think the button after hangovers would end up with, now I protect the button very heavily when I go out drinking and it's like, yeah. Two keys in the nuclear submarine or something. Which, exactly, don't touch my button. It's the red button. It's a very important button.

1:18:37One consistent thing across populations, across demographics, well, across subpopulations also that overall there is definitely a trend to more energy per capita, use more like wealth per capita. and the thing that comes along with it is more opportunity per person. So the thing that seems to be most consistent around this, if I was to point at a single thing that is the most consistent, it's not female education or something, it would actually be just a broad scope of opportunity costs of having a child. And Bill's point of, yeah, but maybe we're discovering our own personal net fulfillment, but I think that comes, if I was to take the economics lens, from we've been increasing the benefit from other ways of spending time, but we've kind of nearly had a fixed cost of having a child throughout generations.

1:19:26So if I take the economics lens and the other way to reduce the opportunity cost, like if I was super villain and I wanted more babies, I reduce female education, I make us poorer, and I increase infant mortality and we have more babies. Terrible answer. Let's not do that. I think maybe the silver bullet is the opportunity cost lens. It's just that it consists of so many things. And maybe the reason we don't see whenever a country tries to do subsidies, cash incentives, all of that, they only ever give like 10 to 20 percent of the lifetime cost of a child. Anyway, so the thing I wonder is like, do you see the reduction of all of the things maybe being sufficient in total?

1:20:08like where we make it easier we increase the cultural appreciation of mothers we increase the fertility range of age we just like really many many things stack together rather than these 10 things well mothers and fathers i want to say and caregivers of all types i think we're gonna have to share these costs um is part of it but yes i mean we wrote this book because we think that something different might be possible. Like if we didn't think it was possible to shift away from depopulation to stabilization, then why would we write this? And I think that's what we learned from thinking of cases like the long-term response to climate change, that you can make progress towards something, even if you don't know at the beginning how you're going to make progress towards it.

1:21:03So I don't have the solution, but exactly for the reasons that you were getting at, Liv, about social influence and that nobody's born knowing what they want, I think if we were to radically change our support for caregiving and parenting, then over the generations, we could create a situation where by expanding people's opportunities, right? By letting people fit more into their lives, we could have people growing up and seeing a model where you can be a parent and have kids and do other great things too. And yeah, I think over time that could shift what people come to expect, what people's vision of a good life is.

1:21:47It's not just going to be a few thousand dollars. It starts with the snoo, but it doesn't end with the snoo. I mean, right now it's summer, which means that my big kid isn't in school and I have to do something else. And that's a huge pain, right? I mean, it also means that he's not learning, um, or at least not learning in the same way, which also matters. And, and so, I mean, there's just so many things that we could, you know, so, so, you know, what my spouse says is like, what we need to do is get rid of the nuclear family and we have to all like live together and take care of the kids like that.

1:22:21And that as long as we insist on the nuclear family, we're hosed. And I don't know if she's right or she's wrong. I'm just trying to say maybe it's just a problem with me she has like what we need to get rid of is being married to you but what's y 'all's thinking about adaptation and my I'm coming from the assumption that yeah more humans typically is good but it seems like if it's so bad at a certain point obviously everyone will realize that and we'll start having more kids so is there a fear that it just will be too catastrophic too fast or the like the the proposal is birth rates get low people look around and say hey birth rates are really low maybe exactly for that reason in sort of a pro-social way we should choose to have more kids yeah or alternatively because if we again we look at history it tends to be that when the world gets kind of shitty and poor and everyone's doing badly what happens no one has anything else to do but have sex and have kids right no but it seems like there's the opportunity because if the world has gotten shitty everyone's poorer the opportunity cost has gone down

1:23:34sure yeah i mean it could be a pro you know a conscious decision or it could be an unconscious decision essentially but it feels like it doesn't seem clear to me that it will just trend downwards exponentially to zero there might be some moment where it's like well now a culture has taken over because everything's so bad people have forgotten what it used to be like and it's like well let's just pop out 10 kids because we've got nothing else to do okay great yeah so i mean we have our graph like you might have like seen the picture that we drew in the new york times article where we basically say okay total fertility rate of 1.6 go and it you know goes on forever and ever and you know people write in to say well of course you shouldn't think that's empirically what will actually happen.

1:24:14And, you know, indeed not, right? It's sort of an, it's the answer to an if-then question. If the birth rate, you know, goes to a number like 1.6, then this is what you'd see. No, I don't think that the population would follow that path forever. I think, you know, eventually, as you say, something important would break and we, you know, would no longer be able to follow that if-then anymore. Is it something important that's going to break, something that's going to, you know, wipe us all out, like maybe a pandemic where there's not enough, you know, so think of, you know, COVID came along, and there were 8 billion of us, and we were able to come up with vaccines that, you know, the vaccine has this property of like a once and for all thing, where, of course, you have to manufacture it and put it in people's arms and get people to come get it but you only need one recipe right and so like in a in a smaller population would we be able to come up with that and I don't know but you know the other possibility is the one that you raise where the whatever knocks us off the path and causes you know the basically makes us poorer and causes birth rates to go up that could be what happens that would be very bad that's not what we're hoping for I think you know that would be a reason not to do this if we thought that or what's going to happen.

1:25:35I don't see a lot of evidence of in a future where people are accustomed to, you know, choosing whether to be a parent or not and have access to contraception to have these tools. A lot of people decide to have more kids for the greater good or something. That's just, that's just sort of an unreasonable. I mean, that's, you know, how many people, that's not how we're that's not how we're fixing climate change exactly you know it's not what we see happening in South Korea we see the birth rate continuing to fall it's not what we see happening in China we see the birth rate continuing to fall and so I guess I'll stop there with some statistical evidence and not to keep speculating yeah I just had a quick I had this weird I had a strange thought I come from the oil and gas world along 15 20 years ago we are 100 % sure about peak oil in America.

1:26:30We're like, there's no way we're going to peak out. And then all of a sudden, technology-wise, we figured out, oh, we can use this technology called fracking and go after shales. And all of a sudden, boom. Is there, I was thinking, can you, like, is it possible, I'm reading all these crazy articles about, like, a ton of young people my age have, like, embryos saved, right? We're, like, smarter. We're, like, thinking ahead. If tomorrow Elon Musk invents some crazy technology where you can take those embryos and like grow them without having to do them yourself and it's healthy and whatever. Could something like that, where you're wrong, Dean's wrong and it's not 10 billion, it's 2030 or something like AI unlocks some sort of technological innovation that we're not thinking about?

1:27:15I mean, in your embryo scenario, does somebody still have to parent them and do the work of taking care of them and feed them and drive them to school and all of that? Yeah.

1:27:30Yeah, I mean, I think I have a lot of confidence in the if-then. If birth rates fall below two for the world as a whole, then global depopulation is what's going to happen. And I also think there's a lot of empirical evidence that should make us think that global average birth rates falling below two is the most likely future and would be that way for a long time. Could something else happen? Sure. I don't have a crystal ball, but I think it's the most likely future. I was just curious on what the data showed for 2020 during the pandemic globally on the population rates. Did we get busy? From my understanding, just a lot of people had a lot of children.

1:28:14I was just wondering what that data showed. Yeah, I don't know. From what I've seen, it was actually kind of the opposite. Fertility rates went down even further. during COVID it was actually quite a really I mean there might have been a slight peak but overall 2020 to 21 they I think a lot of nations reached their lowest fertility rates historically which is interesting not exactly like I think electively I'm sure there were a lot of accidental pregnancies because people are just like locked down and we're like well what else we gonna do but I think elect I have a question for the room real quick for those who don't have children in the room after this conversation, how badly do you want to go make babies?

1:29:01That's a very, it's a really valid question. Seriously, I'm... Like, are you guys going to do your part? What's up? Igor, are you updating?

1:29:11I'll do one of the necessary things to have babies. Have you done enough practice? Be the change, Igor, be the change. Okay, I As a childless person, this actually was kind of my question, sort of to isolate the solution, but just out of curiosity. Is there any significant global data that this change in birth rate is coming from the people that are having no children at all versus meaning fewer people are not having children at all? Or the people who are having children are having fewer because of maybe resources or all these other possible reasons? And then do you think that changes the solution?

1:29:52Because it's such a different question. Going from zero to one is very different than one to two to three. So does it change the way you look at the solutions? I'm so glad you asked that because I just happen to be working on a research paper about that. And the answer is that it's more about people having kids having fewer kids than it is about more people having no kids. So we hear a lot of this narrative about childlessness. but you can sort of, you know, as you say, the statistic, the average number of children amongst people who have children, right, that's been going down too. And in particular, there are lots of countries, like the places where birth rates are pretty low, like your Portugal's and your Russia's, there, the average birth rate amongst people who do have kids would still be low enough for depopulation.

1:30:41And so it's a pretty strong correlation between the overall average birth rate in a country and the average birth rate amongst people who do have kids. And so we see them going down together. And so it's not just like the people who have kids are staying the same. So what are the facts? That number is going down too. In a lot of places, it's low enough that even if everybody were the people who have kids it would still be below two and if you sort of break it down to the into the accounting more of the difference is globally is about people having fewer kids who have them this is a case where the US is a little bit of an exception and the increase in childlessness is a bigger part of the picture for the US overall but if you like plot all the dots from all the countries you know it's it's more about average number of kids amongst people who have kids.

1:31:35Is there any fulfillment data between people who have kids? So on average people have two kids happier than the people who have four kids. Is there any kind of data in that? Yeah, exactly. That's sort of the right question to ask because it's not sort of a randomized experiment whether you have a kid or not. And so like the so Angus Deaton has a paper with Arthur Stone looking at this. it's not about how many kids you have I think it's just on the margin of are you a parent or not and you know what they find is like amongst people who look at the Gallup world poll data so that's these happiness questions and what they find is you know and you know people who have kids like the highs are higher and the lows are lower would be a simple way of summary like more good days more bad days but it's hard to sort of say cause and effect because people choose to have Story checks out.

1:32:28Yeah. Well, actually, one of the things I wanted to say was partly to that point or that question. I've heard an interview with therapists and also people in the family law space that there is, I don't know if this is going to enroll people in having more children from hearing this, but that having one child or two versus three or four, there's a pretty big gap in the amount of enmeshment that occurs. when people have fewer children they are more enmeshed with them and they're positing that this is less psychologically healthy for everybody involved and it leads to more embittered challenging custody cases where the parents like I want the one kid no I want but if it's fourth like please God take them take them for a week okay you have them back now please so so there's some benefit to this and then just a couple other points this thing about aging populations earlier this seems like I'm half Singaporean this is like maybe a very Singapore-specific solution because it's one of the most densely populated countries on Earth.

1:33:26And also the value system, I think, culturally there, it's more socially oriented of what do I do to help the greater good in the group. And they have subsidies, for example, for housing, for aging parents to move into the same complex of flats that their children live in so that they can all live near each other and support one another. And so it puts less strain on government resources. And then last point. Oh, yes. So I don't know how much this would make a difference, but my understanding is the American OB-GYN Association recommends that physicians not offer women a blood draw for AMH anti-malarian hormone that would indicate ovarian reserves because it can cause them undue stress.

1:34:12so if a woman is they will ask about contraceptives um like you know how do you want to prevent pregnancy but they don't say do you want a family in the future do you want to get a sense of your ovarian reserves now um and some women go into paramenopause in their 20s we just don't know and so there is a very simple way to test for this that they're specifically not telling women about as a policy um which might help somewhat at least in the u.s all right has there been any research done on are people having less sex? Are they maybe less sexual with the advancement of technology and people connecting through the phone rather than personally meeting, being one?

1:34:50And the other factor is cost of living. Since it's exponentially higher and more expensive to live, the age of the average person who's even buying their first home is much higher now. How does that relate to just it all being possible? Yeah. So I don't know exactly the answer to the question of whether people are having less sex and whether you know how much that was it does sort of bring me back as everything does to the case that I do know which is India where you know marriage remains almost universal and that young ages and people tend to be having you know a small number of kids and then having permanent contraception surgery so at least that would be one case where people are you know having a small number of children and exactly implementing the plan they want to in sort of in a marriage where, you know, they are having to do well, I mean, there was definitely hugely coercive policies in the 20th century to try to, you know, force people to not have kids in the sense of like, in some cases, involuntarily sterilizing them.

1:36:00um you know that um was awful and hurt a lot of people um um you know these days you know in some cases the official messaging is reversed um but you know it's still the case that like the place where i work like the district capital town where i work in utah pradesh like in the walk from like the office to the hospital you see like a sign painted on the wall that's like has you know that says like don't have too many kids um so i don't know how much that does to anything but um but the other question uh you had another question it was interesting and important yeah and affordability um i mean i think that is important um i think you know we talk a lot in the book about how the affordability of kids can't be the whole story because you know we do see lower birth rates in richer countries.

1:36:55We see that as the world's gotten richer as a whole, birth rates have gone down. We see that places where things are more subsidized. You don't see people having more kids. Here's a sort of little cute economics thing is there is a research paper looking at what happens when young women win the lottery, comparing them as a control group to young women who played the lottery and maybe won a small prize but didn't win the big prize. And so it's pretty much a randomized experiment. And what that paper found, for whatever this is worth, is that the women who win the lottery did not go on to have more kids over the course of their lifetime than the women who did.

1:37:35And so the women who won did not go on to have more kids than the women who did not win. And so I think that at least bounds how much money is the constraint. Steph, I know you had a bunning question. Did you want to ask it? Sure. Okay, so first I'll say that I'm pro-human. I have lots of humans. I have four of them. So I'll put that out there. Winning. Winning. I did it accidentally.

1:38:02It happens to the best of us. I do want to ask, so when thinking about this space, I feel like I'll, first I don't trust humans to predict the future. It feels like we never get it right. Even if you looked at what people were saying last year, no one can predict where we're at now. and so I'm wondering in all of your research is there anyone that you've run into where they just don't have the data yet like you ran into them and you're like oh shit like intuitively this feels like they're on to something but they just don't have the data that's proving it yet and someone that we should be watching let's see at the person level I don't have the answer I don't know one thing that makes me think about though is that this could be a case where like the longer term could be easier to predict than the shorter term.

1:38:50Like you talked about like next year or something like that. I think like next year, who knows, right? You know, one group wins the election, the other group wins the election, you know, who knows? I think I wouldn't want to stand here and say that I think I know what the birth rate in any place or the population size in any place is going to be, you know, five years from now, 10 years from now. You know, migration, for example, would have a lot to do with that. And migration has a lot to do with what's legally permitted. I think this is a case where it's easier to say, you know, just like climate change, it's sort of easy to say, like the big picture, if you burn a lot of carbon dioxide, then you'll increase the, or you burn a lot of fossil fuels and put carbon dioxide into the atmosphere, then you'll increase the temperature.

1:39:32I think here we can say, like, you know, if the world's birth rate goes below two and stay there, then we'll see this exponential depopulation. and I guess I just want to stop there and not try to be more precise than that. Thank you so much, everybody.

1:39:52Thank you all. This has been fun. Thank you. Unsurprisingly, there was a lot of comments and I'm sorry for any of you who didn't get to speak that wanted to. Dean, thank you so much. This was excellent. I hope this is, if anyone was undecided, it's moved you in the direction of babies. I know, Igor, are we going to talk? Back to practice. Again. Thank you so much for having me. Thank you, Dean. This is amazing. And everybody, get his book when it comes out. I really recommend it. Now you can applaud.