Do we need more kids? A research showdown.

Fertility rates are falling around the world, and most people think human reproduction will soon slip below the so-called replacement rate, where the number of babies born can't keep pace with the number of people who are dying. That means the world's population will level out and then start to fall, which has some people worried. — If people don't have more children, civilization is going to crumble. But others argue population decline is exactly what the world needs. — Human beings have overrun the world. — So, do our societies, does our species need more babies or fewer? To explore this question, we randomly assigned ourselves sides? I have a coin here. — Oh, good. — If it's heads, I argue that we need more people. If it's tails, less people. — Gotcha. Okay. — All right. I got tails. Okay, — now we got to go find support for those arguments. — Let's do this. — We spend the next 3 weeks reading papers and talking to experts to prepare for the fact check debate you're about to watch. Get ready for a town showdown. They're facing up with facts so that you get the low down. Today, Adam will be arguing for the proposition that there are too many people in the world, and Joss will be arguing that there are not enough. This sound, [bell] that's the timer. And this sound, that's for when there's a visual on screen for you if you want to see it. There'll be seven rounds, and at the end, you can vote for which side won on Patreon. And you can also head over there to hear Adam and Joss debrief the debate. — Round one. Adam, you have two minutes to make your first argument. Great. I just want to start by taking a real hard look at some of these numbers. When our parents were born, there were about 2 1/2 billion people on this planet. All of human history, we'd grown to 2 1/2 billion. But to add the next 2. 5 billion took just one generation. By the time you and I were born, there were nearly 5 billion people on Earth. And that's going to double again. The UN's median projection says we're going to max out around 10 billion. And even their lowest fertility projection says we're going to keep growing to 9 billion people. There's really no denying that this huge population explosion has hurt the ecosystems that we're part of, that we rely on. And Joss is arguing that somehow 9 billion is not enough. That we need more human beings on this earth. But I'm going to show over the course of this debate that a smaller population is actually a good thing. It's better for the future of our civilization. health of the planet and we can get there without crippling our economies. But before we dive into that, I just want to say that everyone should be able to have the number of children that they want. No government should be coercing people to have more babies or fewer babies. Government should be removing obstacles and empowering their citizens to pursue their choices. And the reality is that right now people are choosing to have fewer babies. Every few years the CDC interviews thousands of American women and ask them if they want children and how many children they intend to have. And a growing share of women say they don't want kids at all. And if you add up all the intended kids, the average comes out to 1. 8 children per woman. So that's below replacement rate. That's means a declining population. And if you ask women under 25, that number falls even further. It's 1. 5 children per women. I'm arguing that we shouldn't fight that trend. We shouldn't fight these people's choices. We should embrace it because this is an opportunity to restore the population down to what it was when our parents were growing up. And that can only help us solve some of the world's trickiest problems. — Okay, Joss, you have 90 seconds to respond. — Okay, you really need to look at the total population numbers charted alongside the population growth rates. And that's where it really becomes clear that our growth rates peaked in the 1960s. So in this way, demography is kind of like spacetime where we are looking at the stars and we're seeing what they looked like hundreds of years ago because of the lag. The population boom that you just talked about reflects achievements that have happened mostly in the past. In the past 75 years, what we're really talking about are about 4 billion African and Asian babies who lived instead of died. This is an incredible achievement that should be celebrated. And now as our fertility rates decline, that is a result of improvements in education, equal rights, and freedom, which we should also celebrate. But then we have to decide where we want to go from here. you've already kind of won this debate. We are on track to see declining population. That is going to happen. And the people who are young today will decide how far and how fast we decline. Um you're right that the number of children people want

has gone down. But when you ask most people, they would say the ideal number of children is two. But all around the world, fertility rates are dropping below that. So, it's not obvious that every additional decline in fertility once we have societies with equal rights and freedom are a result of free choices rather than new barriers that societies have put up that are keeping people from living the lives that they want. — Yeah. I mean, we definitely want to remove any barriers to what people want. But I do I I'm curious about that uh that those surveys that say they ask the question, what do you think is the ideal number of children for a family to have? And most people say two or three. Um, but I think that they're asking the wrong question because that those answers are skewed by sort of cultural norms, nostalgia. Every sitcom has two to three kids in a family. And so you might just say that as sort of describing what you're observing. But you know in those surveys I saw one recently that asked what do you think is the ideal number of children for a family to have? Only 2% said that the ideal size is zero. But when they ask people if they want kids nearly 10% say no. So how do you square that number? A tenth of people say they don't want kids. Only 2% think that's the ideal number. I think that's because ideal family size is like this idealized notion. And so those surveys don't really reflect what people really want. — Well, the thing is that what people want is completely shaped by the societies that we build, right? So we decide whether we have societies that make parenting easy and friendly and desirable. Um and so I what I hope to show in this debate is that we should build those kinds of societies and question whether we are. — Okay, Jos, you now have two minutes for your first argument. Most people are not aware of how much fertility rates have fallen around the world. So this is a trend that has obviously been happening for decades, but the past 10 years have shown that we don't go from like six births per woman to two and then just hold there, right? We're not holding there. And what we really need to talk about here is the statistic of total fertility rate. You hear this a lot in media and conversations about this. It's not the same thing as birth rates. So the total fertility rate is a statistic that imagines a hypothetical woman and how many babies she would have over the course of her life. This is because we can't just wait and see how many kids a 20-year-old today ends up having. We don't have 20 years to find that out. So they use this statistic to try to capture fertility rates at the moment. The replacement rate is around 2. 1 to 2. 2. And right now 2/3 of humanity lives in countries that are below that level. This is not just a rich country issue anymore. So, we're talking about Tunisia, Mexico, Turkey, Iran, Thailand. These are all countries that have lower fertility rates than the United States right now. The Financial Times has a great series of charts showing how demographers keep overestimating what the fertility rates will be. One example is Colombia. The UN thought that there was going to be 700,000 births in 2024. what we actually got there was 450,000 and still the UN thinks that birth rates are going to stabilize. So those projections that you were saying they're based on the expectation that birth rates will stabilize for reasons that are a little unclear. It's just as likely that countries will enter what's called a low fertility trap. So if you have a total fertility rate of one, which is like Spain or China right now, that means that each generation is half the size of the one before it, which means half the potential mothers, they can't just return to replacement rate. They need to actually overshoot it for a long period of time to avoid depopulation. So this is going to unfold slowly. And you know, at the scale of our individual lives, it seems slow. Takes 20, 30 years for a generation to go by, but it's very hard to change course, especially if we can't get on the same page and recognize that this is happening. — Adam, you have 90 seconds for your rebuttal. — Well, I'll just start by saying that I think that this declining population is a good thing, right? So, I am inherently less worried about that than maybe some people might be. Um, but I also think that it's really hard to predict uh population decline. It's hard to predict fertility rates. People have been bad in the past and I'm sure they're we'll struggle with it now. And so drawing a line from a trend we see in the last couple decades to sort of the inevitable end of the human race or a dwindling to some unfortunate size, that doesn't make sense to me. I think that's silly to try and predict that far out. And I'm glad you mentioned that it is it will seem slow because this is a slow process. Like I just want to put

that in perspective for people. You know, we we've already been in this period of population decline in many places. The US birth rate first fell below replacement rate in 1971. So we've been living in this world where things are changing in this way. Um but you know, it's shifted up a little bit. It shifted down. It hasn't been an unstoppable plunge so far. We don't know what's going to happen in the future. And it seems incredibly unlikely that the population decline will be faster than the population rise. Even the most aggressive low fertility scenarios that I've ever seen are saying that by the end of this century when the majority of people watching this will be dead, there still will be more people on Earth than when we were born. It's just a slower process than some sort of sudden shock. Um, and I think that gives us a lot of room to adapt and change. — I would like to add that with regard to the US fertility rate, yes, it went down in the 1970s, it came back up. That bump was because of a change in the composition of the population, not because of a change in behavior. Um, it's entirely a result of uh the higher fertility of foreignb born women of immigrants. And that bump is now gone. They uh their fertility rates have gone down. and the countries that they came from have fertility rates that have dropped. So that's one point. But when you say that like this happens slowly, that doesn't mean that you know like anything could happen to change it, right? We know how many kids are going to enroll in college 20 years from now. Like that's been decided by the people who decided whether to have kids right now or not. And population decline is subject to the same exponential math that population growth is subject to. — Right? We can see a little ways into the future, but I think every decade you travel into the future, it becomes harder to predict. And if we're worrying about something that the math predicts in 200 years, I think that's plenty of time to upend the assumptions that those equations are making and give us a different result. So, I'm just thinking that in the short term, yes, but in the long term, no. We can't predict. Okay, we'll move on to round two. — Before we get too far into it, let's talk about today's sponsor, which is Sockdoc. So, I was reading a really interesting study recently, and it was about what they call continuity of care, which basically means seeing the same doctor over time. It turns out that having that relationship is associated with lower mortality rates. It's really important, but the challenge is often finding that doctor in the first place. And that's where Zachdoc comes in. They exist to remove any of the friction that is keeping us from getting the health care that we need and that we're often already paying for when we buy insurance. Polls have shown that when you put off seeing a doctor, your health often gets worse. So, booking a doctor's appointment should be easier than ordering a burrito in the middle of the night. And with Zockd, it actually is. You don't have to call five different doctor's offices just to be told that they aren't taking new patients or that they don't accept your insurance. You don't have to call anyone at all. You can do it all online. Get in the same week, sometimes the same day. They have more than 100,000 providers from primary care to dental health, eye care, urgent care, and more. So go to zdock. com/howtown. Book a top rated doctor today. If you use our link, which I'll put in the description, that makes us look good. But again, this is a totally free service. And what really matters is that you stop putting off seeing the doctor and get the care that you need. — In this round, Adam and Joss each get to present a stat. Adam, you're up first. You have 1 minute. Great. My statistic is 1. 6 births per woman. I'm quoting from a paper entitled, "Is low fertility really a problem? " In this paper, they studied the economic dynamics in 40 wealthy countries and found that fertility below replacement and modest population decline favor higher material standards of living. So a shrinking population was better for standards of living than a growing one. How can that be? Well, what they found is basically that when you have a slowly shrinking population, you can invest more per kid and that means each kid has more resources, better education. They end up being more productive. An example they use a lot in this paper is Japan, which is the oldest country, the country with the oldest population on Earth. They have a total fertility rate of about 1. 1. But from 1995 to 2024, as its population declined, its GDP shrank by 27%. When you look at the human development index, a common measure of well-being, Japan's rating rose 6%. So with a below replacement fertility rate, they actually saw an increase in well-being. Joss, your response? — Yeah, I wouldn't say Japan is a hell hole, but I would note that Japan's public debt to GDP ratio is getting a

little out of hand, and at some point that may become a problem for them. The paper that you're talking about, it's an interesting thought experiment. Um, they're looking for like what Goldilocks fertility rate maximizes consumption, like balancing the size of the pie and the number of slices, but it's just not the real world. Like this analysis ignores the transition period, right? They run forward several generations till they have a steady age structure, which means that they're kind of abstracting out a lot of the pain that we're going to experience with an aging population. They also assume that an aging population doesn't affect the productivity of the labor force, which is another big assumption. And this paper was published 10 years ago. So I went and looked at the fertility rates of all of the 40 countries in their analysis, and 36 out of 40 of them have fertility rates that have dropped in the decade since this paper was published. We just don't get to choose an optimal fertility rate and hold it there. — I would dispute that this is not looking at the real world. I mean it is modeling uh possible scenarios but based on observations of what's happening in the real world. And when you look at Japan which is very much the real world you do see that over the past 30 years they've managed to increase standards of living with one of the most dramatically aged populations in the world. And they've done that by increasing the workforce participation among seniors among women. They've been very good at incorporating news technologies. is they have these very specific immigration visas that they give to help with the workforce. So, they're sort of a pilot program for a lot of tools that will make these transitions, which are going to be rough. I'm not denying that, but they'll make them more easy to bear and survivable. — Is there like a end point to this analysis or can the population shrink down to like very small and it's still supposed to apply? Well, in this paper that you could basically continue to have these dividends to well-being if you just stayed at 1. 6 indefinitely. Um, you know, it's but that again is like getting so far in the future that — other factors will come to play, — right? All right, why don't we move on? Uh, Joss, you now have one minute to present your stat. My stat is that in France it took around 115 years for their population above the age of 60 to double from 7% to 14%. More than a century. In Vietnam that same change will take just 15 years. So if you look at charts of population aging, you see these really steep lines in large parts of Asia and Latin America. And the reason why that's really important is that a lot of these countries didn't have the time or the economic growth that like Japan had to build robust public pension systems and health care systems for their populations to have a lot of private retirement savings. U Vietnam has a social security system but the majority of seniors do not have access to it because they worked in the informal sector. So this is what economists call getting old before getting rich and it is a threat to the continued development of low and middle inome countries and at the same time right rich countries will need immigrants to address their own uh population challenges and labor shortages to care for our aging populations. So already the US healthare system and um long-term care system is highly reliant on immigrants and that's only going to become more the case and those workers are exactly the same workers that are going to be needed everywhere. — Adam, your response a lot in a lot to respond to in both of those stats. I think that um when it comes to Vietnam, its population is still growing. It's not declining yet and its working population, more importantly is still growing and will continue to grow for a little while. And so that gives you a window of a couple decades really where you have time to prepare the economy and to implement systems that will help with that transition. And in terms of the way that immigration can kind of smooth out some of these transitions, it doesn't have to be a completely extractive exchange. There are already sort of pilot programs in a lot of countries where there's an exchange of training and labor. One example is the NHS in the UK where they offer a residency program for doctors to come from other countries, work in the NHS for a couple years and then they can go back home and they bring that training back to their home countries. So there's a way to set this up so that you actually increase the global supply of skilled workers everywhere. — When you say that they have this time to set up these systems and prepare their countries like yeah they need time but really they need economic growth for that to happen. It's just it's always unfortunate when people who live in really rich countries that have benefited from a huge amount of economic growth like look at these countries and and don't allow them or encourage them to have the same trajectory and experience that led to the lifestyles and the standard of living that we have. — Yeah, it's a problem. But I think you also have to ask, will adding more

babies be part of the solution? And I think that if there was a baby boom in Vietnam tomorrow, those babies are going to be dependent for the next 15 to 20 years, right? And so you're just adding a another a bolus of of dependence on both ends of the population that now you have to invest in. — Why don't we move on to round three? — Showdown. [singing] Third round. — Joss, you have 2 minutes to make your next point. a smaller human population will be less able to solve the big and small problems that we face. That's because people are the source of good ideas. Uh this is obviously the case in areas like science and technology, but it's also the case everywhere. Wherever people are doing things, they are learning from the things that they're doing. They're figuring out ways to do it better. They're sharing that knowledge with everybody else and adding to the cumulative intelligence which is our most precious natural resource. Right? If you look back through human history, it was the land mass that had the highest population that created the most innovation, right? Like the land mass of Europe and Africa and Asia. Whereas more isolated populations in the Americas, in Australia, they didn't have as many people to accumulate and iterate on ideas. And so let's that's the supply side, but let's also not forget the demand side. So if you take How town for instance, our channel, we decided to take the risk to launch this thing with the assumption that there were enough people in the world who would want this very specific kind of video that we make to pay back the cost of, you know, starting the channel of uh the cost of making every single video, which is like pretty big cost upfront. And that's the same, you know, across the economy, you know, when the chef is deciding whether to open a restaurant that sells like Korean, Mexican, vegetarian food or, you know, someone's deciding whether to make a movie or write a book or uh, you know, invest in the technology to create a gadget that's going to make our lives easier. Um, there's this big fixed upfront cost that needs to be justified by a substantial market. There was a study of the pharmaceutical industry in the US which showed that a 1% increase in the market size led to four to six% more new medicines, right? And this is really relevant for things like rare diseases where if there's not enough humans with the condition, the condition is not going to be addressed. So bigger markets encourage problem solving. It just really benefits all of us for there to be large pools of people who want the same things that we want. Okay, Adam, and you now have 90 seconds for your response. — Totally agree that population size is one of the drivers of innovation, but I can think of a bunch of other forces that can also drive innovation. One is just investment, public investment. We've just seen the US slash a bunch of investment into research. Restoring that or doubling it even would definitely improve the amount of innovation that's happening, the amount of creativity that we can harness. Another factor you mentioned like communication being an important part and how if you're a more diffuse population it's harder to have those conversations but you know we can concentrate people into institutions and with increased connectivity throughout the world that kind of communication can still happen and then another thing is we can just increase the number of people who are part of those conversations by making sure more people have good education. If you don't ever get to go to high school, it's harder to be part of these conversations. So, we can raise the education standard for the whole world and actually increase the population of people who are innovating while the population is decreasing. We can [clears throat] do this kind of innovation with a few billion less people. We went to the moon when the population was 3. 6 billion people. Fleetwood Mac recorded rumors when the population was 4. 1 billion. So we don't need 10 million people for great acts of creation. — Well, the population going that direction had a larger number of young people than the population will going the other direction. So there is some relevance to that I think and you're totally right that increasing investment in research, increasing education, those are all things that are going to increase innovation. But like where does that you have to really think about where that money comes from? And the question is whether a bigger or smaller population is likely to provide the tax base to support that kind of investment. And when you have an aging population, we're going to see a bigger and bigger amount of our public budgets going into health care. It's very expensive. older folks spend, you know, maybe several times more on health care and we're going to have to pay for that, which is going to force some tough decisions about where our

governments can invest elsewhere. — All right, moving on. Adam, you now have two minutes for your next argument. — I don't think Jos can deny that human population growth so far has put a huge strain on natural resources and the environment. You can sort of take your pick of whatever metric you want. uh groundwater is being depleted. 40% of fisheries are being overfished. We're losing a Denmark sized patch of forest every year. Of course, there's CO2 emissions that is a big focus. The latest IPCC report says the GDP per capita and population growth remain the strongest drivers of greenhouse gas emissions in the last decade, which they put in parenthesis, robust evidence, high agreement. So, we're really sure about that. So, every person we add to the population adds to that strain. But I want to focus on one particular corner of this impact and that's the loss of other forms of life. It's not that complicated of a picture. Every extra human needs more space to live. And that space includes all the area that's need to needed to grow and raise the food they eat. And so we've taken over the habitats of other species, taking their resources. This graph here sort of is a snapshot of that. This shows the biomass of mammals in the world. And you can see the familiar uptick of humans, that orange space, but that comes along with it this huge population of domesticated animals, mostly livestock, that are taking habitat from other animals. And then you can see the wild mammals have declined. If you look at vertebrate populations across the board, their populations have fallen on average by 73% in the last 50 years. Hundreds of thousands of species are facing extinction and that's the direct result of our actions. Part of it is pollution, climate change, but the biggest part is just the amount of land that we need. And so what population would allow us to successfully share the world with all these other species? That's really hard to estimate obviously because it all depends on how those people live. But every realistic estimate that I've seen says it's less than the number of people we have right now. And there's they sort of tend to land around the 34 billion uh level which again is sort of between the population when our parents were born and when we were born. — Okay, Jos, you now have 90 seconds for your rebuttal. — I want to use my tag team here. — Tag team. — It's from Dean Spears, who's an economist and uh author of a book called After the Spike. When China's particle air pollution was off the charts in 2013, it got international attention and was called the air apocalypse. In the decade after that, the size of the Chinese population grew by 50 million people, but particle air pollution in China fell by more than half. And it's not just China. The population of the world as a whole grew by 750 million people over that decade. And particle air pollution fell, but not everywhere. It didn't fall in India. And that's because leaders in India didn't make the policy decisions that China did to shut down coal plants or regulate industries. When I was a kid in the 80s, the big famous threat was the hole in the ozone layer. But my kids don't add to the hole in the ozone layer because the Montreal Protocol in 1987 banned the use of chlorofluorocarbons. Before that, it was leaded gasoline, but the Clean Air Act addressed that. The thing is we could list every environmental challenge and there are many and they are serious and they are real and we must confront them. But whenever we've confronted humans destructive environmental activity before it's always been not by reducing the number of humans but by confronting the destructive activity that humans do. — You know this is the same reason why you don't see environmental organizations advocating for policies that would somehow drastically cut the human population. as if there was any way to do that wasn't like fully evil. And Spears also has an analysis where they looked at climate specifically. And they showed that population decline that's going to happen is just too slow to be any part of a solution to climate change. We need to decarbonize in the next couple of decades. And when you look at the two population paths, one declining and one stabilizing, um, you just don't see a difference. What we need are technologies and policies and you need people to push for both of those. — I'd say a couple things to that. One is that another big difference between China and India is that China's population did fall. Obviously, that was because of policies that we would think of as unethical. But right now, we don't have to resort to those policies to see a population decline. We can just embrace the trend that's already happening and let people make those choices and the population will decline. it it's not that it won't have any effect. I think his analysis found that it had a small effect. Too small to solve all the problems. But if you look at the analysis of the technology, the decarbonization efforts that we've made, they're also too small. All of these pieces on their own are too small, but together they can have an impact. So

why not try all of them at once? And that's actually I'm use my tag team because a bioethicist that I interviewed made that point pretty well. I thought — tag team — let's get some of our uh ecological improvements from smart technologies and let's get some of our ecological improvements from getting rid of unnecessary superfluous consumption and then let's get some from gradually and humanely shrinking our numbers. I think that's the way to go. Put that all together. Let's give ourselves the best chance to come through the next hundred years without disaster. Uh and not just not without disaster, but with a good future where everyone has enough food and we still keep some of the beauty and vibrancy in the natural world too. — He seems nice. But I would say if you look at things that need to be done like there is some cost to cleaning up after ourselves, right? the stock of CO2 emissions that's already in the atmosphere. We will have technologies that can remove it. We will have to pay for them because they'll be expensive and the bigger tax base that you have, the more we can share that cost among ourselves. So, it's not obvious that there's just you can just decline the population and you get a net only a net benefit for the environment there. What I would also say is that if policies matter um and they do like you mentioned uh the cost of livestock right now lots of countries actually subsidize the beef and dairy industries they're lowering the prices we're not getting the signal of their actual cost and so that's a policy question and we need people to push for that change of policies and the fact is that environmentalists should make more environmentalists So Donald Trump, our president, he believes climate change is a hoax famously. If you look at the birth rates of the counties that supported him, they are substantially higher than the birth rates of the counties that voted against him. And you see similar trends in Europe, there is some indication that decline in fertility among people with progressive values has contributed to the rightward turn of politics on that continent. That's just something for, you know, environmentalists to keep in mind that if they want to transmit their values and their priorities to the next generation, uh, they are going to need to produce the next generation. — It makes me nervous to think about population engineering as a way to address some of these policy uh, problems. But to your earlier point, I actually think that there obviously needs to be investment to solve these problems. It's going to take a lot of work and money and resources to solve them. But there are signs that some aspects of lowering population do cost us nothing and lead to better outcomes. Not so much in the decarbonization space, but in this other problem that's sort of uh a different one of land use. You've seen countries like Croatia that have had their population decline like 20% in the last 30 years and they've just pulled back from farmland and very naturally that farmland has become wilderness again and you've seen a rebounding of native populations of wolves and ibicks and their native antelopes and that happened without too much human intervention at all. It was sort of a natural progression where agriculture became wilderness again. But I think you have to also recognize the solutions that can only come out of technology and policy. And the fact is that we've seen a lot of countries once they, you know, get out of poverty, they meet their the needs of their citizens, they start to care about uh paying for protecting the environment, they do make progress. We've brought species back from the ex the brink of extinction. You know, we have decoupled uh emissions from population in lots of countries. Actually, a lot of countries have decoupled economic growth from carbon emissions because of this shift to clean energy, which is happening faster than people predicted. — All right, let's move on to round four. — In this round, you each dare to ask one another a question. Joss is up first. Okay, so in 1968 uh Paul and Anne Erlic published the population bomb which predicted you know widespread famine and unrest due to overpopulation. It has gone down as one of you know history's most famous bad takes because their predictions were false. They couldn't foresee how innovation would allow us to feed more people with less resources. So my question is uh what do environmentalists and what should we learn from the mistakes that they made and how do we avoid making the same mistakes as we consider population issues going forward? — Well, I think the lesson from the Erlics is that it's really hard to predict the future. It's hard to predict what advances technology will do and you can

predict things incorrectly in both directions. You might not anticipate some technology that is making going to make population growth okay, but you also might not anticipate some technology like for example AI that might make labor shortage okay. New technology could also improve our economies by increasing productivity in the future and making some of these concerns about an aging population and a lowering workforce kind of moot. The lesson is not to try and change people's choices to meet some imagined future that you've constructed with your models, but rather to see what people's choices are in this moment and try to build a world that works with those choices. Right now, people are choosing to have fewer children, and so we should try to build a world that works with that. All right, Adam, you drop your question. So you're saying we need to reverse population decline, but my question is how can we do that? Can you name a single policy out there in the world that has raised fertility rates where the population is declining back up to replacement levels? No, we have not seen that any government has figured out how to return uh the society's above replacement rate. But I think that doesn't mean that we can't do anything about it. Actually, if you look at some of the research that's been done that really considers the counterfactual quite closely, you do see sort of marginal improvements when you make child care more affordable and you expand parental leave. So, it's really hard for me to believe that uh governments are all that pro-atal if the costs of child care and housing have grown faster than wages. That's kind of the biggest thing um that probably affects people's decisions about whether they are going to have families and how big their families will be. And um I just don't think that there's any evidence that we've done much at all on those fronts. — Well, this segus really well into my pet peeve. — In this round, you'll each call out a common talking point that gets on your nerves. Adam, go ahead. I think that a lot of people, especially politicians, think that there's going to be some magic wand they can wave policywise that magically makes their populations grow again. And when you look out, like you said, we haven't seen that working yet. Maybe there's things we can do, but they're most likely to cause marginal gains. You look at countries that are what I would call pretty pro-atalist in the way that you're describing social democracies in Scandinavia where they have a lot of support for parents and you know they they're working on cost of living all these things and the population is still declining. There's still a low fertility rate. So, I just don't think that there's that many levers that we can push that don't become coercive or creepy um to raise the population. And to me, that means that we should be focusing on a whole suite of solutions that include adapting to a lowering population versus just trying to force the population back up. And right now, I see a mismatch in where the energy and thought is being focused. — So, the pet peeve is that people are proposing family-friendly policies. a lot of politicians are really focused on increasing fertility rate in a way that is impossible that we've seen is impossible. Some of those policies I think should be implemented anyway. Um some of them are are less good I think for the fabric of society. But I think that by focusing on them and believing that somehow they'll have this effect, they're not having a cleareyed view of the future and making the other changes they need to make in their societies. — Yeah, that seems fair to me. I mean, I think uh perhaps the area is worth more research and study to try to figure out what might be possible. uh I'm not convinced we've tried everything, but yeah, some of this may be out of the reach of policy and may be more in the hands of cultural factors. And there's an economist who's doing some really interesting work on this. Her name is Claudia Golden. Um and she's looked at a subset of wealthy countries, all of which are below replacement rate, and she charts them by their fertility rate on one axis and then how imbalanced um the household labor is. So on one side you have countries like Korea, Japan and then southern Europe like Italy, Greece, Spain where the men do way less housework and child care than the women and their fertility rates are lower than countries like Sweden, Norway, Canada, France where the gender relations are more egalitarian and you see that their um fertility rates are higher. Again, they're still below replacement, but

it's worth interrogating these small differences. You know, why what is the difference between France's society and Korea's society? We have a lot to look at culturally just because, you know, giving people cash might not convince them to have a kid. You know, there may be other barriers that are cultural that can explain why those pronatal policies aren't necessarily working. — Jos, your pet peeve. Okay, so my pet peeve is that it's really common to hear these days that now is a uniquely bad time to bring children in the world. I think this is pretty wrong. Um, I certainly empathize with anyone who is dissatisfied with the state of the world, who feels a lot of uncertainty about the future. These are confusing times. The challenges are big and real, but the thing is that they always have been. So you know you go back a couple hundred years and 30 to 50% of babies did not survive the first five years of their lives right um they didn't have any uh defenses against infectious disease they didn't um they fought in world wars you know just uh in the recent past chunks of the US population did not have access to equal rights are we to believe that all of our ancestors were foolish for bringing us into the world. Like I'm personally very happy to have been born when I was. And I think the issue here is a lot of media incentives and social algorithms that encourage widespread negativity, nihilism, and that kind of can have distorting effects. So there was a poll that showed that half of Democrats in the US believe that climate change is going to render the Earth uninhabitable. It's very hard to find um an actual climate scientist who agrees with that. So I this really bothers me. There have always been horrors and injustice and I think the question is whether there are going to be people to fight those problems and fix them. — Totally. I totally agree with this actually and I think that there you see these incentives at play on both sides where you can sell more books if you portray something as a catastrophe but there are really hard problems ahead and I think that they'll be made marginally easier in an important way with fewer people. All right, let's move on. — In this round, you'll each have to concede a point. Joss, you're up first. Okay. So I will concede that we are not good at predicting the future. It will be many decades before we notice substantial declines in our population and in that time you know a lot could happen. You mentioned AI. The thing that people always fail to anticipate is technological change. So we're going to have to keep an eye on that. It could go either way. you know, if AI plays out in the utopic vision and we all um don't need to work anymore and we get a big check from like a limitless source of wealth, um great. If AI wipes out jobs and doesn't return anything to the people in return, um that's just going to push birth rates lower. I can tell you that. The other thing I'm keeping an eye on is in vitro gamattogenesis. So they are figuring out how to make eggs from skin cells which would remove the age constraint on female fertility. And so um it's this is being done in rodents but it's totally possible to imagine a future where you know women have all the time in the world to establish their lives to shop around for the right partner um and then start having babies in their 40s and 50s instead of their 20s and 30s. So all of which is to say it's hard to know exactly what the right level of alarm is about falling birth rates. Um and that is the point that I would concede. — All right. And Adam, your point to concede. I would concede that there is reason for some alarm about um some of these programs like social security in the US. an aging population is going to result in some strains on these programs. And the promise that these programs are making to people who are going to retire in 20 years, they're not going to be able to keep those. That's just a mathematical impossibility at this point. There are things that we can do to redesign those programs. There are tweaks that a lot of economists talk about that could basically erase most if not all of the shortfalls that these programs are facing, but those changes are pretty politically unpopular. And we don't really have a politician yet who's come along and said, "I'm brave enough to really take this on and make those changes. " [singing] — Okay, onto the final round. Joss will be up first. You'll have 90 seconds to make

your final point. — The truth is, Adam, you already won this issue. Our most likely future is one of smaller aging populations. And the question is, should we do anything to slow or stop that? You make the case that more people are more problems. And while that's true in a lot of ways, it's less than half the story. I think more people are also more solutions. And actually there are more solutions because more people create more problems. So it's more people more problems more people to notice and study those look for solutions more people to pay for solutions more progress. And then sometimes more progress means more problems and we start the cycle all over again. That's the human project. It's an unfinished one. It's messy but we clean up our messes. And the story of the last 200 years when we've had this huge population boom is one of humans conquering diseases, of feeding more people, finding better sources of energy, and then finding even better sources of energy. We're here because of people who fought for rights for the education of women, for scientific advances that keep babies alive. Are we really just going to drop the baton now in a whimper of negativity and seed the future to authoritarians and digital people? No. I do not think that it is anyone's responsibility to reproduce. But I do think it is our responsibility to really interrogate all of the ways that we have made parenting seem like a bad deal. You know, the costs are public spaces friendly to families are workplaces friendly to families. Are we teaching people to be good partners? In what ways are we judging people's parenting all the time? You know, what it all really boils down to is are we making sure that mothers can have the lives and relationships that their daughters would want for themselves? I think that's the whole ball game. — All right. And this week, Adam, you got the last word, so your final argument. I don't think that the human project is inextricably linked to a need to just keep growing, to get bigger and bigger all the time. I don't think that Joss has shown that we need more than 9 billion people or that a gently declining population is a catastrophe. The restoration to historic population levels started decades ago and it's going to continue for generations. It's not some sudden shock. Even if the global fertility rate fell to 1. 5 over the next decade, which is way faster than the most extreme low fertility predictions, we would still not reach the population of our birth around 5 billion people for a century. And with that amount of time, we can adjust policies and programs and adapt to changing economic conditions. We can improve health. We can share labor and knowledge between countries. We can deploy technology in ways that make up for labor shortages and all that is a good idea anyway. Right now, people around the world are deciding to have fewer children and we can't change that. In some cases, those choices are motivated by a very rational concern about the problems that our species cause. Um, and that's what really what this is all about. Our collective decision is bringing the population size down to a level that will do less damage to the environmental systems that we rely on. This isn't a crisis. It's an opportunity to create a world where every child that's born can thrive. Who was right? Who was wrong? Who won the fight? Was it Adam or Jos? Go and vote on our Patreon where we'll [singing] discuss what we really thought about this. I'm going to count down and I want you to say who you think won the debate. 3 2 1 Showdown. We're glad you stuck around so you could get the low down. Town showdown.