Latest / Daniel and Kelly’s Extraordinary Universe / Should we be worried about overpopulation or depopulation?

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Should we be worried about overpopulation or depopulation? · Daniel and Kelly’s Extraordinary Universe

• 0:07
  Speaker 1: The average number of children each woman gives birth to
• 0:10
  Speaker 1: globally has been steadily declining. To some, this is a disaster.
• 0:16
  Speaker 1: Elon Musk, for example, says that collapsing birth rate is
• 0:19
  Speaker 1: the biggest danger civilization faces by far, with fourteen children
• 0:24
  Speaker 1: at last count, he seems to be attempting to avert
• 0:27
  Speaker 1: this crisis single handedly. Folks concerned with the decline in
• 0:31
  Speaker 1: birth rates advocate for policies that incentivize having more children.
• 0:35
  Speaker 1: But on the other hand, a decline in birth rate
• 0:38
  Speaker 1: is music to the ears of others. As someone who
• 0:41
  Speaker 1: adores both human beings and nature, I would love to
• 0:45
  Speaker 1: see living standards rise as population size falls. It seems
• 0:50
  Speaker 1: reasonable to assume that more humans translates into a greater
• 0:53
  Speaker 1: environmental impact. So if humans are choosing to have fewer babies,
• 0:58
  Speaker 1: that sounds like a win win for humans and for nature. Plus,
• 1:01
  Speaker 1: I've heard humans are going to level out at eight
• 1:03
  Speaker 1: billion people anyway, so any decline in population size would
• 1:07
  Speaker 1: be short lived, and anyway, this seems like a problem
• 1:10
  Speaker 1: for future generations. Right, Why should we start worrying about
• 1:13
  Speaker 1: population size now? Well, today we're going to talk to
• 1:17
  Speaker 1: Dean Spears and Michael Jeruso about their recent book After
• 1:21
  Speaker 1: the Spike, Population Progress and the Case for People. They
• 1:25
  Speaker 1: are concerned that the future will see a precipitous decline
• 1:28
  Speaker 1: in human population size, and they want to see us
• 1:31
  Speaker 1: start taking this problem seriously now so that we have
• 1:34
  Speaker 1: plenty of time to find compassionate solutions to the problem
• 1:38
  Speaker 1: before society start to feel the pinch. Welcome to Daniel
• 1:41
  Speaker 1: and Kelly's Extraordinary Universe.
• 1:56
  Speaker 2: Hi. I'm Daniel. I'm a particle physicist and a professor
• 1:59
  Speaker 2: a you see Irvine, and I have two children and
• 2:02
  Speaker 2: a dog.
• 2:02
  Speaker 1: Hello. I'm Kelly Weener Smith. I study parasites and space
• 2:06
  Speaker 1: and I have two children, two dogs, seven goats, two cats,
• 2:11
  Speaker 1: and as of next week, I will have five ducks
• 2:14
  Speaker 1: and two geese.
• 2:16
  Speaker 2: Is that it really how many rats are living on
• 2:18
  Speaker 2: the property?
• 2:19
  Speaker 1: Well, you know, there used to be a lot of them,
• 2:22
  Speaker 1: but we took care of them. And I know, I
• 2:25
  Speaker 1: know you and I really like rats, but not when
• 2:28
  Speaker 1: they're eating the chickens food. And it was just complicated
• 2:31
  Speaker 1: and it was us or them.
• 2:33
  Speaker 2: So my question for you, Kelly is why did you
• 2:35
  Speaker 2: decide to have two children and not three or seventeen?
• 2:39
  Speaker 2: And you considered goats part of the Wiener Smith clan.
• 2:44
  Speaker 1: I love the goats, but not as much as I
• 2:46
  Speaker 1: love my kids, and so there's a hierarchy there for sure.
• 2:50
  Speaker 2: Wow, species is much Yep, Yes, it's true.
• 2:53
  Speaker 1: I like humans. I do like humans a lot. We
• 2:56
  Speaker 1: decided to have two because after we had the second
• 2:58
  Speaker 1: one and he was old enough to be like sleeping
• 3:02
  Speaker 1: a little bit better, I thought to myself, I do
• 3:05
  Speaker 1: not have the energy to go through those long nights again.
• 3:09
  Speaker 1: And my second pregnancy was a high risk. I ended
• 3:12
  Speaker 1: up in the ICU with hypertension after my son was born,
• 3:15
  Speaker 1: and so I was like, I think my body is
• 3:17
  Speaker 1: telling me two is good, and yeah, what about you?
• 3:21
  Speaker 1: Why'd you pick two?
• 3:22
  Speaker 2: I feel like two is a special number because it's
• 3:24
  Speaker 2: the same number as parents in the family, And so
• 3:27
  Speaker 2: I think people really underestimate, like how much more work
• 3:30
  Speaker 2: a third child is. And you know, when we talk
• 3:32
  Speaker 2: to the economists today on the program, they're talking about
• 3:34
  Speaker 2: these numbers one, two, three, But I really feel like
• 3:37
  Speaker 2: there's a barrier there past two where it just really
• 3:40
  Speaker 2: becomes much much harder. And also if you have like
• 3:42
  Speaker 2: two academics and young careers, and it just didn't seem
• 3:46
  Speaker 2: plausible for us. Plus every pregnancy for us is high
• 3:49
  Speaker 2: risk because Katrina is Type one diabetic. Yeah, so it
• 3:51
  Speaker 2: just felt like more than we could handle.
• 3:53
  Speaker 1: So you and I both read the book, and they
• 3:55
  Speaker 1: do address how difficult and time consuming it is to
• 3:58
  Speaker 1: have children, also like how beauty full and amazing it is.
• 4:01
  Speaker 1: And one of their suggestions is that, you know, society
• 4:04
  Speaker 1: needs to modify in ways that make it easier, you know,
• 4:08
  Speaker 1: easier to get child cares, or less work for the
• 4:11
  Speaker 1: moms and for the dads, and just trying to make
• 4:13
  Speaker 1: the whole thing easier. But I agree, two was a
• 4:16
  Speaker 1: lot more work than one. And I thought, I thought, well,
• 4:19
  Speaker 1: I'm already doing this parenting thing. It won't be that
• 4:21
  Speaker 1: much more. It's a lot more, And I'm still glad
• 4:24
  Speaker 1: I did it, for sure, But yes, three is to
• 4:27
  Speaker 1: me conceivable.
• 4:29
  Speaker 2: So thank you to all the parents out there having
• 4:32
  Speaker 2: more than two children and helping us maintain the human population.
• 4:36
  Speaker 1: That's right, Yes, it's an important job and needs to
• 4:39
  Speaker 1: be done well. And so speaking of the human population,
• 4:42
  Speaker 1: the book that we're talking about today sort of projects
• 4:45
  Speaker 1: forward what the human population might look like as we
• 4:47
  Speaker 1: go through multiple generations, and so we wanted to know
• 4:51
  Speaker 1: what our audience thinks about how many people will be
• 4:54
  Speaker 1: on the planet in three hundred years, and here are
• 4:57
  Speaker 1: their answers.
• 4:58
  Speaker 3: That's a good question, but realistic unanswable, and my humble opinion,
• 5:01
  Speaker 3: because there are too many unknown variables that can occur
• 5:03
  Speaker 3: in three hundred years that could wipe out a portion
• 5:05
  Speaker 3: of all of humanity, from our own deeds to an
• 5:08
  Speaker 3: asteroid impact like the size that took out the dinosaurs,
• 5:11
  Speaker 3: or a combination of things like successive volcanic eruptions, wildly
• 5:14
  Speaker 3: ballenced anomious tornadoes, and plant earthquakes. So I don't think
• 5:17
  Speaker 3: the question is realistically answerable.
• 5:19
  Speaker 4: So the optimist in me would say that overall population
• 5:25
  Speaker 4: would be in a slow decline by then, since as
• 5:31
  Speaker 4: education levels increase around the world and the standard of
• 5:34
  Speaker 4: living increases around the world, people tend to have fewer
• 5:37
  Speaker 4: children on average. In fact, they tend to have a
• 5:41
  Speaker 4: negative birth rate, So I would say.
• 5:44
  Speaker 2: One billion individuals.
• 5:45
  Speaker 4: I kind of feel like we'd go back down to
• 5:47
  Speaker 4: something like that. The pessimist in me says that we
• 5:52
  Speaker 4: blow ourselves up with a nuclear disaster.
• 5:55
  Speaker 5: Birth rates in all countries have dropped. I expect in
• 6:00
  Speaker 5: three hundred years, we will have less population than today.
• 6:04
  Speaker 6: It's easy to naively imagine living like the Jetsons three
• 6:07
  Speaker 6: hundred years from now, but considering the unsustainably outrageous rate
• 6:11
  Speaker 6: of our populace over consuming all natural resources except sunlight,
• 6:15
  Speaker 6: I anticipate a bleak existence. For However, many humans can
• 6:18
  Speaker 6: subsist on what remains. Choosing a number, I doubt even
• 6:22
  Speaker 6: first order billions.
• 6:24
  Speaker 7: Well, I think that in three hundred years there will
• 6:28
  Speaker 7: be social pressure to just replace yourself. I think with longevity,
• 6:33
  Speaker 7: people will be living for a very long time and
• 6:37
  Speaker 7: we will avoid overpopulation.
• 6:40
  Speaker 8: I personally think we have a horrible future as a species.
• 6:44
  Speaker 8: We are terribly overpopulated right now without enough resources. My
• 6:50
  Speaker 8: guess is in three hundred years they'll probably be less
• 6:52
  Speaker 8: than ten percent of the population left. Sadly, I don't
• 6:57
  Speaker 8: think there will be any people lift on planet in
• 7:00
  Speaker 8: three hundred years.
• 7:02
  Speaker 6: We are our own worst enemy, and considering the trajectory
• 7:05
  Speaker 6: we're going in right now, I would say.
• 7:08
  Speaker 2: Less of five percent of the current population, precisely zero.
• 7:13
  Speaker 5: There's no way we'll make it that far.
• 7:15
  Speaker 2: So, Kelly, why did you pick three hundred years? It's
• 7:18
  Speaker 2: a really specific timeline.
• 7:20
  Speaker 1: Oh. I went to one of the figures in their book,
• 7:24
  Speaker 1: and I looked at a point where the projected population
• 7:27
  Speaker 1: size was quite a bit lower, and so I thought,
• 7:29
  Speaker 1: you know, at this point, people can say up or down,
• 7:31
  Speaker 1: and according to their projections, the answer should be definitely down.
• 7:35
  Speaker 1: But I gotta be honest, I did not expect answers
• 7:38
  Speaker 1: to be so dark dark from our audience. Usually there's
• 7:42
  Speaker 1: like a bunch of jokes thrown in there, like I
• 7:44
  Speaker 1: don't know, but here's a poop joke, and I'm like, oh,
• 7:46
  Speaker 1: I love you guys. But this was like we're probably
• 7:49
  Speaker 1: gonna blow ourselves up. Yeah, And they're like, oh man,
• 7:51
  Speaker 1: a couple answers like that, and so wow.
• 7:54
  Speaker 2: Well, I don't know. Maybe digging this deep into science,
• 7:57
  Speaker 2: into physics and biologies made people existential. You know, they
• 8:00
  Speaker 2: realize how fragile our meat bags are on this tiny
• 8:04
  Speaker 2: speck of dust we're floating on in this vast universe.
• 8:07
  Speaker 2: So it's sort of hard in that context to imagine
• 8:09
  Speaker 2: we're going to be around in three hundred years, three
• 8:11
  Speaker 2: thousand years, three million years. It seems like incredible we
• 8:14
  Speaker 2: are here at all.
• 8:15
  Speaker 5: Yeah.
• 8:16
  Speaker 1: No, I absolutely agree, and I share concerns about what
• 8:20
  Speaker 1: our species is going to do because we have nuclear
• 8:23
  Speaker 1: weapons and are we going to like just totally accidentally
• 8:25
  Speaker 1: blow ourselves up? I hope not, but from a like
• 8:29
  Speaker 1: resources and population standpoint for anyone who's feeling negative but
• 8:33
  Speaker 1: would like to have their spirits slightly lifted, I really
• 8:36
  Speaker 1: liked Not the End of the World by Hanna Richie.
• 8:39
  Speaker 1: She runs our world in data and so she really
• 8:43
  Speaker 1: digs into the numbers for a bunch of these resource problems,
• 8:46
  Speaker 1: and it's like one of my favorite books because I
• 8:48
  Speaker 1: love the way she addresses these problems with data, and
• 8:51
  Speaker 1: in the end she decides, look, we can handle this
• 8:54
  Speaker 1: and it doesn't need to be too catastrophic in terms
• 8:57
  Speaker 1: of all of us changing our lives, but we do
• 9:00
  Speaker 1: need to make some changes and here are some suggestions.
• 9:02
  Speaker 1: And anyway, I really enjoyed her book.
• 9:04
  Speaker 2: Awesome. I'll check that out.
• 9:06
  Speaker 7: Well.
• 9:06
  Speaker 2: Today we're talking about the book After the Spike, Population
• 9:08
  Speaker 2: Progress and the Case for People by Dean Spears and
• 9:11
  Speaker 2: Michael GURUSO out today. Go check it out. Kelly and
• 9:14
  Speaker 2: I both read this book. I really enjoyed it because
• 9:17
  Speaker 2: I love books that take apart sort of popular misconceptions like,
• 9:21
  Speaker 2: here's the standard lore everybody believes. Why did you believe that?
• 9:25
  Speaker 2: Why is that not true? And what's more likely to happen?
• 9:28
  Speaker 2: And this book does a great job of that. It's
• 9:31
  Speaker 2: a little bit nerdy and economical and data heavy, but
• 9:34
  Speaker 2: only as much as you need to convince yourself that
• 9:37
  Speaker 2: these guys know what they're talking about and the issues
• 9:39
  Speaker 2: they raise are real issues. It's also fun and their
• 9:42
  Speaker 2: jokes and as you'll hear in our conversation today, these
• 9:44
  Speaker 2: guys are good at explaining stuff.
• 9:46
  Speaker 1: Yeah, and I also felt like they were sort of
• 9:48
  Speaker 1: kindred spirits with us because for a lot of the answers, it's, look,
• 9:52
  Speaker 1: we just we don't know, we don't have the data,
• 9:54
  Speaker 1: and they're very honest about what we do know what
• 9:57
  Speaker 1: we don't know. Yeah, and I really appreciate that they're
• 9:59
  Speaker 1: t taking on this problem because it has sort of
• 10:01
  Speaker 1: become politicized, as I mentioned in the intro, and I
• 10:05
  Speaker 1: feel like they might be sort of making themselves targets,
• 10:07
  Speaker 1: which is maybe why they are so so tied to
• 10:11
  Speaker 1: their data, the data and their arguments. And anyway, they
• 10:14
  Speaker 1: make some pretty interesting arguments. And let me go ahead
• 10:17
  Speaker 1: and give their bio real Quick. Spears and Jeruso are
• 10:20
  Speaker 1: professors of economics and demography at U t Austin. Jeruso
• 10:24
  Speaker 1: served as a senior economist in the Biden White House.
• 10:27
  Speaker 1: Spears runs the nonprofit research Institute for Compassionate Economics, which
• 10:32
  Speaker 1: helped establish a give well backed newborn health program in India.
• 10:37
  Speaker 9: Welcome to the show, guys, Thanks so much for having us.
• 10:40
  Speaker 5: Glad to be here.
• 10:41
  Speaker 1: My husband Zach has been absolutely raving about your book.
• 10:44
  Speaker 1: He loved it, so I was excited to have a
• 10:45
  Speaker 1: chance to read it. So let's jump right in. One
• 10:48
  Speaker 1: of the things that I like about this book is
• 10:49
  Speaker 1: that it gets me to think about population size way
• 10:54
  Speaker 1: differently than I thought about for like, literally all of
• 10:56
  Speaker 1: my life. So I was born in nineteen eighty two.
• 10:58
  Speaker 1: When I was born, popular size was about four point
• 11:01
  Speaker 1: six billion, and it's currently over eight billion. And I'm
• 11:05
  Speaker 1: an ecologist, so I usually think about population size as
• 11:09
  Speaker 1: being the thing that kills animals and destroys ecosystems and
• 11:13
  Speaker 1: stuff like that. So when I started hearing that, you know, oh,
• 11:16
  Speaker 1: eventually population size is going to go down, that sounded
• 11:19
  Speaker 1: like good news to me. And so your book was
• 11:22
  Speaker 1: sort of like mental whiplash for me. So explain to
• 11:25
  Speaker 1: us why population is going to go down and why
• 11:29
  Speaker 1: instead of feeling like, oh, this is maybe good news,
• 11:31
  Speaker 1: why this is something that we should be concerned about.
• 11:34
  Speaker 9: So we were also born in the eighties and we
• 11:37
  Speaker 9: also grew up hearing about overpopulation. But right now, global
• 11:41
  Speaker 9: depopulation is the most likely future. And what global depopulation
• 11:45
  Speaker 9: means is that every decade, every generation, the world's population
• 11:49
  Speaker 9: is going to shrink. That's the path that we're on.
• 11:52
  Speaker 9: Within a few decades, the world's population will begin to decline.
• 11:56
  Speaker 9: And there's no reason to think that once that happens,
• 11:59
  Speaker 9: it'll automatically reverse.
• 12:00
  Speaker 5: So a big.
• 12:01
  Speaker 9: Question before us is should we welcome that or should
• 12:05
  Speaker 9: we want something else to happen. But even before that
• 12:08
  Speaker 9: is why it's happening. And the fundamental explanation is that
• 12:12
  Speaker 9: birth rates are low and falling. So that's a way
• 12:16
  Speaker 9: that humans are different from other animals. If you're thinking
• 12:18
  Speaker 9: about ecology, that humans have cultures in society and decision
• 12:23
  Speaker 9: making and decide how many children to have. And over
• 12:26
  Speaker 9: time we've been deciding to have fewer children. And you know,
• 12:30
  Speaker 9: when I say low birth rates, you might think something
• 12:33
  Speaker 9: like South Korea where there is zero point seven of
• 12:35
  Speaker 9: a kid on average for two adults right now. But
• 12:38
  Speaker 9: actually it would be enough for global depopulation to have
• 12:42
  Speaker 9: low birth rates like in the US where it's one
• 12:45
  Speaker 9: point six kids per two adults, or like Texas or
• 12:48
  Speaker 9: Latin America where it's one point eight, because depopulation will
• 12:52
  Speaker 9: be the unavoidable consequence of there being fewer than two
• 12:56
  Speaker 9: children in the next generation to replace two adults in
• 13:00
  Speaker 9: the last generation. In two thirds of people now live
• 13:03
  Speaker 9: in a country where the birth rate is below that
• 13:06
  Speaker 9: two births per two adults average, that would stabilize the population.
• 13:10
  Speaker 2: And what exactly is new about that piece of knowledge, Like,
• 13:14
  Speaker 2: is this something that demographers and economists have known for
• 13:17
  Speaker 2: a long long time but the general population isn't aware of,
• 13:20
  Speaker 2: Or have we recently learned something about birth rates? Why
• 13:23
  Speaker 2: this conflict between our knowledge that birth rates are following
• 13:26
  Speaker 2: and the general sense among the whole population that the
• 13:28
  Speaker 2: population is growing out of control.
• 13:30
  Speaker 5: Yeah, I think that's a really good question. The fact
• 13:33
  Speaker 5: of the matter is that falling birth rates are not
• 13:35
  Speaker 5: some entirely new phenomenon that just popped up on the
• 13:38
  Speaker 5: scene in the last five or ten years. During this
• 13:41
  Speaker 5: period of rapid global population growth, you know, over the
• 13:45
  Speaker 5: last fifty sixty years, that was a period during which
• 13:49
  Speaker 5: birth rates were already falling. It's just really hard to
• 13:52
  Speaker 5: see and appreciate that birth rates are falling in a
• 13:55
  Speaker 5: time when the goal population is spiking up so quickly. Right,
• 13:58
  Speaker 5: So you mentioned you were born in nineteen eighty, Kelly,
• 14:01
  Speaker 5: or sorry, nineteen eighty two. I was born in nineteen eighty.
• 14:04
  Speaker 5: But the birth rate has been falling for a very
• 14:07
  Speaker 5: long time.
• 14:07
  Speaker 1: Ian.
• 14:07
  Speaker 5: It's been falling for as long back as we have
• 14:11
  Speaker 5: good statistics to document it. So birth rates were falling
• 14:15
  Speaker 5: in France and the seventeen hundreds, birth rates were falling
• 14:17
  Speaker 5: in other places in Europe in the eighteen hundreds. Birth
• 14:20
  Speaker 5: rates have been falling for the globe overall for as
• 14:24
  Speaker 5: long back as we have any good statistics now, like
• 14:27
  Speaker 5: there have been temporary blips, like the post World War
• 14:30
  Speaker 5: two baby boom, but on average, over the whole world,
• 14:34
  Speaker 5: over time frames that span decades rather than individual years
• 14:38
  Speaker 5: where things might bounce up or down, birth rates have
• 14:40
  Speaker 5: been falling. And so I just think it's really hard
• 14:43
  Speaker 5: to come to grips with the idea that even as
• 14:45
  Speaker 5: the population is rising birth rates have been falling.
• 14:49
  Speaker 2: Can you break that down a little bit for those
• 14:50
  Speaker 2: of us who don't always think in terms of differential equations,
• 14:53
  Speaker 2: How is it possible for the population to be rising
• 14:56
  Speaker 2: and the birth rate to be falling?
• 14:57
  Speaker 5: Okay, good question. Population changed At the basic level is
• 15:01
  Speaker 5: the difference between birth rates and death rates. So there's
• 15:04
  Speaker 5: two ways that population can increase. Births can go up
• 15:08
  Speaker 5: or deaths can go down. And the revolution that's happened
• 15:11
  Speaker 5: around the world in the past two centuries has not
• 15:15
  Speaker 5: been birth rates climbing. It's been death rates falling, and
• 15:18
  Speaker 5: in particular, the death rates of children falling.
• 15:21
  Speaker 2: So that sounds like good news.
• 15:23
  Speaker 5: Yay, Yes, that's very good news.
• 15:25
  Speaker 3: Yay.
• 15:26
  Speaker 5: I mean it's really good news. It's sort of hard
• 15:28
  Speaker 5: to appreciate from a modern perspective just how awful the
• 15:32
  Speaker 5: mortality rates of children and babies were not all that
• 15:36
  Speaker 5: long ago. So a couple hundred years ago, the sort
• 15:39
  Speaker 5: of the global average for mortality for a kid would
• 15:43
  Speaker 5: be something like one in three kids dying before age five, right,
• 15:49
  Speaker 5: And so as we've learned to keep ourselves and our
• 15:53
  Speaker 5: children alive through better sanitation, through an understanding of the
• 15:58
  Speaker 5: drum theear of disease, through better water, through better nutrition,
• 16:01
  Speaker 5: eventually through vaccines later at our history, what that's meant
• 16:05
  Speaker 5: is that more people have grown up to become adults
• 16:07
  Speaker 5: and to have children of their own. So the part
• 16:10
  Speaker 5: of the equation that's been changing this time is that
• 16:13
  Speaker 5: death rates have been falling and birth rates have been
• 16:15
  Speaker 5: falling too. It's just that they've been chasing death rates downward.
• 16:19
  Speaker 5: And the net effect of all of that over the
• 16:21
  Speaker 5: past one hundred years two hundred years has been just
• 16:25
  Speaker 5: a skyrocketing of the global population. So, just to put
• 16:28
  Speaker 5: that in some perspective, in eighteen hundred, there were about
• 16:31
  Speaker 5: a billion of us worldwide. About a century later, in
• 16:34
  Speaker 5: nineteen twenty five we passed two billion, and then since then,
• 16:37
  Speaker 5: in the last hundred years, we've quadrupled to the present
• 16:41
  Speaker 5: eight point two billion. And all of that action has
• 16:43
  Speaker 5: been about declining death rates that have been declining faster
• 16:46
  Speaker 5: than birth rates have been declining.
• 16:48
  Speaker 1: And so is the idea that at some point we're
• 16:50
  Speaker 1: going to max out on what we can do in
• 16:53
  Speaker 1: terms of reducing death rates, and now the birth rates
• 16:56
  Speaker 1: are going to start being more important.
• 16:58
  Speaker 5: Yes, yes, we're going to in out on what we
• 17:01
  Speaker 5: can do for minimizing death rates. Thankfully, mortality rates for
• 17:05
  Speaker 5: children are so low that they're pressing up against a
• 17:07
  Speaker 5: zero lower bound, so there's just not much more room
• 17:11
  Speaker 5: for them to fall. Meanwhile, fertility rates continue to fall.
• 17:14
  Speaker 2: Can't we all just transform into immortal cyborgs and solve
• 17:17
  Speaker 2: this problem?
• 17:17
  Speaker 5: That would be? That would be that would be.
• 17:21
  Speaker 2: Something I love seeing you search or an adjective there?
• 17:26
  Speaker 9: Well, I mean, okay, so there is actually there's something
• 17:29
  Speaker 9: interesting there. I want to jump in on that because
• 17:31
  Speaker 9: that is a question that we get, which is, could
• 17:34
  Speaker 9: lower mortality rates solve this problem? We don't mean lower
• 17:38
  Speaker 9: info mortality rates? What sort of brought us up to
• 17:40
  Speaker 9: spite people's like what if people just stop dying in
• 17:42
  Speaker 9: older age and live longer than so, like, what if
• 17:44
  Speaker 9: instead of dying on average at seventy five or something,
• 17:47
  Speaker 9: we live twice as long and died at one hundred
• 17:50
  Speaker 9: and fifty?
• 17:51
  Speaker 4: Right?
• 17:51
  Speaker 9: Would that be enough to knock us off the path
• 17:54
  Speaker 9: and make it so it's no longer the case that
• 17:56
  Speaker 9: depopulation is the most likely future. And they answered that
• 18:00
  Speaker 9: question is surprisingly no. Now you asked out differential equations
• 18:05
  Speaker 9: and I won't get into it. But just think of
• 18:06
  Speaker 9: it as like this. If everybody still has two kids
• 18:10
  Speaker 9: or one point six kids on average for two adults,
• 18:13
  Speaker 9: then we're going to have the same phenomenon where the
• 18:16
  Speaker 9: next generation is smaller than the generation before. A given
• 18:19
  Speaker 9: generation will live longer, so the number of people alive
• 18:22
  Speaker 9: and any one time will be greater, but depopulation will
• 18:26
  Speaker 9: still be what's happening. As generation after generation gets smaller
• 18:28
  Speaker 9: and smaller.
• 18:29
  Speaker 2: You're just stretching out the time scale.
• 18:30
  Speaker 9: Befasted exactly, stretching out the timescale. Now it could be
• 18:33
  Speaker 9: if we live to be one hundred and fifty instead
• 18:35
  Speaker 9: of living to be seventy five. And also the biology
• 18:39
  Speaker 9: of reproduction change that instead of having you know, kids
• 18:43
  Speaker 9: in our twenties and thirties and maybe forties, you had
• 18:45
  Speaker 9: a couple of kids in your thirties, a couple kids
• 18:47
  Speaker 9: in your fifties, a couple kids in your seventies. Right
• 18:50
  Speaker 9: then we would get off the path from depopulation. But
• 18:53
  Speaker 9: it wouldn't be because we were living longer. It would
• 18:56
  Speaker 9: still be because we were having more kids. I'll pass,
• 19:01
  Speaker 9: I don't know, I mean, what are you going to
• 19:02
  Speaker 9: do with all that time when you're one hundred and
• 19:04
  Speaker 9: forty and sleep read read we.
• 19:07
  Speaker 2: Might need to be cyborgs that to keep up with
• 19:09
  Speaker 2: our toddlers when we're one hundred and thirty. That does
• 19:11
  Speaker 2: not sound like a lot of fun.
• 19:13
  Speaker 1: That's hard. I've been telling a bunch of my friends
• 19:15
  Speaker 1: that I read this book and have wanted to like
• 19:18
  Speaker 1: start conversations with them about it, and a lot of
• 19:20
  Speaker 1: them will say to me, well, that doesn't match up
• 19:23
  Speaker 1: with what I've heard. What I've heard is that the
• 19:25
  Speaker 1: Earth's population is going to settle at eight billion and
• 19:28
  Speaker 1: we're going to stay there. And a couple people have
• 19:30
  Speaker 1: said this to me, do you know where that figure
• 19:33
  Speaker 1: came from? And could you explain why it's wrong?
• 19:36
  Speaker 9: Yeah. So I think it's just that people have known
• 19:41
  Speaker 9: that population growth was slowing, and there's just like a
• 19:44
  Speaker 9: trope or something that's come out of you know, population
• 19:47
  Speaker 9: growth is slowing and it's going to hit zero, and
• 19:49
  Speaker 9: there just isn't a lot of thought about what happens next.
• 19:53
  Speaker 9: So you might read a newspaper article it says, you know,
• 19:55
  Speaker 9: demographers that come out with new information that shows that
• 19:58
  Speaker 9: population growth is slowing in going to hit zero. Yes,
• 20:01
  Speaker 9: but then what happens next you throw a ball up
• 20:04
  Speaker 9: into the air, and at some point it's vertical velocity
• 20:08
  Speaker 9: is going to hit zero. But that's not the end
• 20:10
  Speaker 9: of the story, right The same force that slowed its
• 20:13
  Speaker 9: ascent is eventually going to bring it back down. And
• 20:16
  Speaker 9: I think people just aren't seeing that second side of
• 20:19
  Speaker 9: the story, that just as falling birth rates have slowed
• 20:22
  Speaker 9: the growth rate in the population, falling birth rates are
• 20:26
  Speaker 9: also going to bring the population size down.
• 20:29
  Speaker 2: So are you suggesting that we haven't had any sort
• 20:31
  Speaker 2: of realistic model in the sort of popular discussion of population,
• 20:36
  Speaker 2: that it's all just been assumptions about how things are
• 20:39
  Speaker 2: going to stabilize.
• 20:40
  Speaker 9: I think there has been a lot of thinking that
• 20:44
  Speaker 9: because the population size is growing, it's going to continue growing,
• 20:49
  Speaker 9: even though there have been signs all along that that
• 20:52
  Speaker 9: probably wasn't going to be the case. So all the
• 20:54
  Speaker 9: way back in nineteen eighty, a long time ago, as
• 20:58
  Speaker 9: we've already discussed on this one, and five people already
• 21:01
  Speaker 9: lived in a country where the birth rate was below two.
• 21:05
  Speaker 9: You know, in the nineteen seventies, Europe passed below to Japan,
• 21:09
  Speaker 9: passed below to Cuba, Australia, Canada passed below too. In
• 21:12
  Speaker 9: the nineteen seventies, and so not only have birth rates
• 21:15
  Speaker 9: been falling for not just decades, but centuries. It's long
• 21:20
  Speaker 9: been the case that we could have seen this coming.
• 21:24
  Speaker 9: But I think because rapid exponential population growth due to
• 21:28
  Speaker 9: low mortality was so new on the historical scene that
• 21:31
  Speaker 9: got everybody's attention, and so it just wasn't that many
• 21:35
  Speaker 9: that thought through that if then, if the world's average
• 21:39
  Speaker 9: birth rate falls below two, then what's going to happen next?
• 21:42
  Speaker 9: And the evidence pointing towards that being the likely future.
• 21:45
  Speaker 2: And you mentioned earlier that birth rates vary a lot
• 21:47
  Speaker 2: from country to countries, South Korea versus other places, And
• 21:50
  Speaker 2: you know, I've heard anecdotally about subpopulations that have very
• 21:54
  Speaker 2: high birth rates. I remember my wife in grad school
• 21:57
  Speaker 2: learning about some population where they have like seven eight
• 22:01
  Speaker 2: children on average. What do we know about the sort
• 22:04
  Speaker 2: of variation among subpopulations? Are we going to see the
• 22:08
  Speaker 2: global population decline but some populations grow very rapidly to compensate.
• 22:12
  Speaker 5: What's sort of interesting, and I think flying under the
• 22:16
  Speaker 5: radar in the popular discourse about this is that really
• 22:20
  Speaker 5: almost every region on Earth has either low fertility or
• 22:25
  Speaker 5: falling fertility. So it's really easy to think that this
• 22:28
  Speaker 5: is a phenomenon that's like special to Southeast the rich
• 22:31
  Speaker 5: economies of Southeast Asia, or maybe to Europe or the US.
• 22:35
  Speaker 5: But you know, we're here at Texas, and the birth
• 22:38
  Speaker 5: rate in Mexico, just south of the border is lower
• 22:40
  Speaker 5: than the birth rate in Texas. The fertility rate in
• 22:43
  Speaker 5: Latin America as a whole is something like one point eight,
• 22:47
  Speaker 5: which is below the replacement rate. Let's see. So the
• 22:51
  Speaker 5: three largest countries in the world are India, China, and
• 22:55
  Speaker 5: the United States, and all three countries have birth rates
• 22:58
  Speaker 5: below replacement and those are places that are very different.
• 23:01
  Speaker 5: They're different socially, they're different economically, they range. You know,
• 23:04
  Speaker 5: India's a developing country, China's middle income country. The United
• 23:07
  Speaker 5: States is an advanced economy. But basically everywhere in the
• 23:11
  Speaker 5: world we have low birth rates. And the exceptions to
• 23:14
  Speaker 5: that places like subs Haer in Africa. Birth rates are
• 23:17
  Speaker 5: still high. So it's still something like four kids per
• 23:19
  Speaker 5: two adults, but that number has also been falling over
• 23:22
  Speaker 5: the last fifty years, and demographers tend to project that
• 23:26
  Speaker 5: will continue to fall into the future as subs Haer
• 23:29
  Speaker 5: in Africa continues its development in terms of rising incomes,
• 23:33
  Speaker 5: rising opportunities, rising education.
• 23:35
  Speaker 1: So let's take a break and when we get back,
• 23:37
  Speaker 1: we'll talk about what we know about why birth rates
• 23:40
  Speaker 1: fall and how good we are at predicting this stuff.
• 24:03
  Speaker 1: And we're back.
• 24:04
  Speaker 7: Mike.
• 24:04
  Speaker 1: At the end of the last segment, you were talking
• 24:06
  Speaker 1: about how birth rates in the Sahara region have gone
• 24:10
  Speaker 1: from four to Are they dropping from four or did
• 24:13
  Speaker 1: they go from higher than four to four?
• 24:15
  Speaker 5: They've gone from something like six in the middle of
• 24:19
  Speaker 5: the twentieth century to something like four today.
• 24:21
  Speaker 1: So how good are we at predicting this kind of
• 24:24
  Speaker 1: stuff in like a ten year frame for example?
• 24:27
  Speaker 5: So in a ten year frame, professional demographers are good
• 24:30
  Speaker 5: at predicting population trajectories. The reason that demographers are pretty
• 24:34
  Speaker 5: good at predicting population sizes over a course like ten
• 24:37
  Speaker 5: years is that the population just has a lot of
• 24:40
  Speaker 5: inertia in it, so no matter what happens to they
• 24:43
  Speaker 5: were sticking too much on calculus here. But a fertility
• 24:46
  Speaker 5: rate is a flow and population is a stock, and
• 24:49
  Speaker 5: so you can change the flow as much as you
• 24:51
  Speaker 5: want instantaneously and it's going to have no immediate effect
• 24:55
  Speaker 5: on the stock. So in terms of predicting the population tomorrow.
• 24:59
  Speaker 5: I can pred debt very well, even though I don't
• 25:01
  Speaker 5: know how many babies will be born today, because most
• 25:04
  Speaker 5: of that prediction is built up in the stock of
• 25:07
  Speaker 5: people who are already alive. We know how people age
• 25:11
  Speaker 5: and die in their later years. We can predict that
• 25:13
  Speaker 5: with pretty good statistical accuracy. And so the uncertainty is
• 25:17
  Speaker 5: really about fertility and changes, and fertility actually take a
• 25:21
  Speaker 5: long time to play out into changes in population size. Now,
• 25:26
  Speaker 5: how good is anyone predicting whether fertility rates will stay low,
• 25:30
  Speaker 5: not just in the next decade, but in the next
• 25:32
  Speaker 5: half century, the next century. I think we should be
• 25:34
  Speaker 5: pretty clear that nobody knows for sure. But what we're
• 25:37
  Speaker 5: seeing around the world is a convergent pattern of low
• 25:41
  Speaker 5: fertility fertility below too. And history is not a guarantee
• 25:47
  Speaker 5: of future performance. Is That's what they say in stock
• 25:49
  Speaker 5: market predicting. But if we look around, we shouldn't ignore history.
• 25:53
  Speaker 5: And if we look around the world at all of
• 25:55
  Speaker 5: the countries where over a full childbearing lifetime fertility rates
• 25:59
  Speaker 5: have ever fall in below one point nine, there's twenty
• 26:03
  Speaker 5: six countries in that category. In none of those have
• 26:06
  Speaker 5: lifetime fertility rates meaning over the course of women's entire
• 26:09
  Speaker 5: life ever risen above two again, So that zero and
• 26:13
  Speaker 5: twenty six record isn't a guarantee of what will happen,
• 26:16
  Speaker 5: but it would be something that we would do well
• 26:18
  Speaker 5: to take seriously as a risk for the future.
• 26:21
  Speaker 2: So I want to understand what we know about why
• 26:24
  Speaker 2: this is happening, and then also talk in a minute
• 26:26
  Speaker 2: about things people have tried and why that might or
• 26:29
  Speaker 2: might not work. But what do we know about the
• 26:32
  Speaker 2: overall trends that are causing this.
• 26:35
  Speaker 9: So surprisingly less than you might think. You know, everybody
• 26:38
  Speaker 9: has a theory of why birth rates are low and falling,
• 26:43
  Speaker 9: but everybody's theories are different, and none of them really
• 26:46
  Speaker 9: captured the bigness of falling birth rates. And by bigness,
• 26:50
  Speaker 9: I mean we've talked about how it's something that's been
• 26:52
  Speaker 9: going on not just for years or decades, but for centuries.
• 26:55
  Speaker 9: And also that's happening in societies that are very different
• 26:59
  Speaker 9: from one another around the world.
• 27:00
  Speaker 2: And so we can't blame it all on Joe Biden,
• 27:02
  Speaker 2: for example.
• 27:03
  Speaker 9: You can't blame it all on Joe Biden. You can't
• 27:04
  Speaker 9: blame it all on any one thing. There's going to
• 27:07
  Speaker 9: be no silver bull exc So you hear people you know,
• 27:10
  Speaker 9: depending on as you say, there are sort of preconceptions
• 27:13
  Speaker 9: thinking about well, maybe it's about capitalism or the free
• 27:18
  Speaker 9: market or neoliberalism that's causing the problem. Or maybe somebody
• 27:21
  Speaker 9: might say it's about feminism or the retreat for marriage
• 27:25
  Speaker 9: or the decline of religion that's causing the problem. But whatever,
• 27:28
  Speaker 9: whatever your theory is, you can find an exception. So
• 27:32
  Speaker 9: for me, I learn a lot by thinking about India,
• 27:35
  Speaker 9: which is the country that I study in my research
• 27:37
  Speaker 9: and where I work. And so India is now not
• 27:39
  Speaker 9: only the world's most populous country, but the world's most
• 27:42
  Speaker 9: populous below replacement country. It's below too also, even though
• 27:46
  Speaker 9: India was the place in the middle of the twentieth
• 27:49
  Speaker 9: century that was the center of these overpopulation fears. And
• 27:53
  Speaker 9: what makes India so interesting is that it's a society
• 27:56
  Speaker 9: where religion continues to be important and in almost everybody's lives,
• 28:02
  Speaker 9: not just on a piece of paper, but actually something
• 28:04
  Speaker 9: that's part of their practices. Almost everybody gets married and
• 28:08
  Speaker 9: at young ages. Almost everybody gets married at young ages
• 28:11
  Speaker 9: and starts having kids at young ages. And here's what's
• 28:14
  Speaker 9: particularly striking is that female labor force participation in India
• 28:18
  Speaker 9: is still pretty low in international comparison, So in a
• 28:21
  Speaker 9: place like the US or Europe, there's an important story
• 28:26
  Speaker 9: about conflicts between career and family being part of why
• 28:30
  Speaker 9: people aren't having so many children. In fact, that's the
• 28:33
  Speaker 9: title of Claudia Golden's books. She's a Nobel Prize winny
• 28:36
  Speaker 9: economist's career and family, and this is very important in
• 28:39
  Speaker 9: many people's lives. But even that's not the explanation that
• 28:42
  Speaker 9: works everywhere, because it couldn't be what's going on in
• 28:44
  Speaker 9: India because so many of the women aren't working in
• 28:46
  Speaker 9: the paid labor force but still having below replacement birth rates,
• 28:50
  Speaker 9: and so no theory is right or applicable everywhere. And
• 28:54
  Speaker 9: so part of what's so striking is that, yes, there's
• 28:57
  Speaker 9: variability across countries, but that very really is shrinking. As
• 29:01
  Speaker 9: as birth rates fall everywhere, countries are becoming more similar
• 29:04
  Speaker 9: in this way, and so what we're seeing is a
• 29:07
  Speaker 9: convergent outcome, and that's part of what makes us think
• 29:10
  Speaker 9: that depopulation is so likely.
• 29:13
  Speaker 1: So Mike kind of already addressed this, but while I
• 29:15
  Speaker 1: was reading the book, this was a question that kind
• 29:17
  Speaker 1: of kept going through my mind. So I want to
• 29:19
  Speaker 1: sort of bottom line this. So we don't understand why
• 29:22
  Speaker 1: birth rates are falling, So we don't know for sure
• 29:26
  Speaker 1: that things won't change when we hit a population size
• 29:28
  Speaker 1: of six billion, for example, But we have really good
• 29:31
  Speaker 1: data on trends which suggests we should be concerned about this.
• 29:35
  Speaker 1: Would that be a fair way of sort of summarizing
• 29:37
  Speaker 1: the argument.
• 29:38
  Speaker 5: Yeah, And I think we could say more too. I
• 29:40
  Speaker 5: think we can sort of do a little bit of
• 29:42
  Speaker 5: introspection here. Sometimes we can too quickly jump to the
• 29:46
  Speaker 5: idea that, well, this is like an unsustainable trend. You know,
• 29:49
  Speaker 5: birth rates can't keep falling. I mean, the first thing
• 29:52
  Speaker 5: to say there is that birth rates wouldn't need to
• 29:54
  Speaker 5: keep falling, whether they're already low. They we just have
• 29:56
  Speaker 5: to stay low. And then the question is, couldn't it
• 29:59
  Speaker 5: be the case that people could continue to choose to
• 30:01
  Speaker 5: have the sort of families that they do now. I mean,
• 30:03
  Speaker 5: in a world that was shrinking, that fell to six
• 30:06
  Speaker 5: billion or four billion, I think it's quite plausible that
• 30:11
  Speaker 5: if nothing else in society changed, people could look around
• 30:14
  Speaker 5: and think. You know, lots of people thinking that two
• 30:16
  Speaker 5: kids as the right number for them. Some people thinking one,
• 30:19
  Speaker 5: some people thinking zero, some people thinking three or more.
• 30:22
  Speaker 5: I think people could continue to make those sort of
• 30:24
  Speaker 5: choices even as the population was falling. Sometimes people think
• 30:28
  Speaker 5: that there's going to be some natural rebound to two,
• 30:31
  Speaker 5: that two is some sort of special number when it
• 30:34
  Speaker 5: comes to fertility, and two might be the number that
• 30:37
  Speaker 5: a lot of people choose. But two is not a
• 30:39
  Speaker 5: special number in terms of a population average. We've never
• 30:42
  Speaker 5: had a population average in any population any time that
• 30:45
  Speaker 5: just held exactly at two. When birth rates fall, they
• 30:48
  Speaker 5: fall right across two, and they don't. There's no like
• 30:50
  Speaker 5: a magnetic force pulling them back up to two. So
• 30:53
  Speaker 5: I think there's lots of reasons to think that low
• 30:56
  Speaker 5: fertility could continue even in the face of a flawing
• 30:59
  Speaker 5: global population.
• 31:00
  Speaker 2: I think you're bumping up on something really interesting there,
• 31:03
  Speaker 2: which is implicitly doing differential equations. You know, you're telling
• 31:07
  Speaker 2: us that people don't respond to the density of people
• 31:10
  Speaker 2: around them. It's not like families get together and they're like, hmm,
• 31:12
  Speaker 2: there's lots of kids in the kindergarten, Let's have fewer kids.
• 31:15
  Speaker 2: Or while kindergartens seem empty, let's have more kids. That's
• 31:18
  Speaker 2: not sensitive to the population itself, right.
• 31:21
  Speaker 9: And it's more than that, it's that it might not
• 31:23
  Speaker 9: even seem that different. And so you know, in Texas
• 31:26
  Speaker 9: right now, the average is one point eight. What if
• 31:29
  Speaker 9: the average instead were two point one. You know, that
• 31:33
  Speaker 9: would make the difference for the world as a whole
• 31:36
  Speaker 9: between depopulating and growing. But I don't think life would
• 31:41
  Speaker 9: seem very different living in a society with an average
• 31:43
  Speaker 9: one point eight from living in a society with an
• 31:45
  Speaker 9: average of two point one. When you're you know, jogging
• 31:48
  Speaker 9: around the park or going to the store, it would
• 31:50
  Speaker 9: feel pretty similar. And I think, you know, back to
• 31:53
  Speaker 9: the question of how did this all slip under everybody's
• 31:55
  Speaker 9: radar and how did we get on the path of
• 31:57
  Speaker 9: depopulation with that everybody noticing? I think I think part
• 32:00
  Speaker 9: of it is because, at least in the United States,
• 32:02
  Speaker 9: where we were right around this two level for a
• 32:05
  Speaker 9: long time, one point it's just not going to feel
• 32:08
  Speaker 9: that different from two point two, but it's going to
• 32:10
  Speaker 9: have very different consequences for the long term future.
• 32:13
  Speaker 2: And the story we're sort of getting to is that
• 32:16
  Speaker 2: birth rates and rates of production of children somehow depends
• 32:21
  Speaker 2: on a lot of complicated factors that it's not always
• 32:23
  Speaker 2: obvious to dig out. And it reminds me this story
• 32:26
  Speaker 2: I remember from my wife being in graduate school shit
• 32:29
  Speaker 2: a friend who was working to study this population of
• 32:31
  Speaker 2: hutter Rights, a small religious community in the Midwest, and
• 32:35
  Speaker 2: they have like an enormous fertility rate, like huge numbers
• 32:38
  Speaker 2: of children. And I remember these researchers studying like why
• 32:41
  Speaker 2: is it, why are they so fertile? And eventually the
• 32:43
  Speaker 2: answer was they just have sex every day and why
• 32:47
  Speaker 2: they have so many kids. And so it's not like,
• 32:50
  Speaker 2: you know, we want to populate the earth, or kindergartens
• 32:52
  Speaker 2: are too empty. It's just like a product of lots
• 32:55
  Speaker 2: of choices people are making about.
• 32:57
  Speaker 1: Their days, but their numbers are going down too.
• 33:00
  Speaker 5: We talk a bit in the book, not about the
• 33:02
  Speaker 5: hutter rates, but about like the Pennsylvania Dutch, the Amish,
• 33:05
  Speaker 5: and we talk about it because I think a sort
• 33:07
  Speaker 5: of a certain kind of math inclined person would hear
• 33:11
  Speaker 5: these arguments and think, huh, well, it's one thing to
• 33:15
  Speaker 5: say that many populations have birth rates that would lead
• 33:18
  Speaker 5: to decline, but there are these subcultures like the Amish
• 33:20
  Speaker 5: that just have tons of kids. Right, So even if
• 33:23
  Speaker 5: we're not having a lot of kids in the rest
• 33:25
  Speaker 5: of America. The Amish are having a lot of kids,
• 33:28
  Speaker 5: and you could do a sort of extrapolation to think, well,
• 33:30
  Speaker 5: if the Amish keep having more and more kids, they're
• 33:33
  Speaker 5: going to build up to be a larger and larger
• 33:34
  Speaker 5: fraction of the population. And you know, so you know,
• 33:38
  Speaker 5: we look this up and the recent population growth rates
• 33:41
  Speaker 5: of the Amish or something like four percent a year,
• 33:44
  Speaker 5: and if you just extrapolate that naively, then you know,
• 33:47
  Speaker 5: in two hundred years there's going to be a billion
• 33:49
  Speaker 5: Amish in the world. But we don't think that argument
• 33:51
  Speaker 5: makes an awful lot of sense for a couple of reasons.
• 33:55
  Speaker 5: One is that sort of high fertility enclaves, whether it's
• 33:59
  Speaker 5: the Amish or any other, their fertility is also going down,
• 34:03
  Speaker 5: like Kelly alluded to. So, you know, maybe last century
• 34:07
  Speaker 5: the Amish we're having eight kids per two adults. Today
• 34:11
  Speaker 5: the estimates put it as something like five or five
• 34:14
  Speaker 5: and a half kids per two adults. It's hard to know.
• 34:16
  Speaker 5: There's not a census of the Amish the way that
• 34:18
  Speaker 5: there's like a census of Texas. So reason one is
• 34:21
  Speaker 5: that even among high fertility subcultures, what counts as high
• 34:24
  Speaker 5: fertility is changing over time, and you know, Sunday high
• 34:28
  Speaker 5: fertility might be in two kids instead of one, rather
• 34:30
  Speaker 5: than five kids instead of three. The other reason that
• 34:33
  Speaker 5: we shouldn't count on the Amish outnumbering grains of sand
• 34:37
  Speaker 5: on the beach is that people don't always adopt the
• 34:41
  Speaker 5: cultural practices of their parents. We see cultural change all
• 34:45
  Speaker 5: over the world. South America is changing from being more
• 34:49
  Speaker 5: Catholic to becoming more Protestant over time, just as one example.
• 34:53
  Speaker 5: But you know, in our own lives, I think we've
• 34:55
  Speaker 5: all had the experience of being teenagers and projecting one
• 34:57
  Speaker 5: cultural practice or another of our parents. These these links
• 35:00
  Speaker 5: that connect generations aren't perfect. And you really have to
• 35:04
  Speaker 5: push this idea of cultural heritability pretty far to think
• 35:07
  Speaker 5: that even as the Pennsylvania Dutch ran out of Pennsylvania farmland,
• 35:11
  Speaker 5: because you know, they're spilling across continents, because there's just
• 35:14
  Speaker 5: so many of them, that somehow these cultural practices and
• 35:18
  Speaker 5: preferences are going to be inherited one for one from
• 35:21
  Speaker 5: parent to child.
• 35:23
  Speaker 1: I think some of that cultural stuff is at play
• 35:25
  Speaker 1: with the Hutter rates. Hutter rates are communal. So my
• 35:28
  Speaker 1: husband and I spent a lot of time reading about
• 35:30
  Speaker 1: them when we were trying to decide if communes would
• 35:32
  Speaker 1: be a good model for early space settlements, and so
• 35:36
  Speaker 1: we became sort of experts in hutter rates, and they
• 35:38
  Speaker 1: were also lamenting their declining birth rates.
• 35:42
  Speaker 2: I keep waiting for somebody to make a weird al
• 35:44
  Speaker 2: joke here. Nobody's going to talk about how we're not
• 35:45
  Speaker 2: going to be living in the future Amish paradise.
• 35:48
  Speaker 1: Now we missed that cultural touchstone. Let's talk a little
• 35:53
  Speaker 1: bit about why depopulation could be bad. So, you know,
• 35:57
  Speaker 1: as an ecologist, the idea that we might have four
• 36:00
  Speaker 1: billion people, like, I don't want there to be zero people.
• 36:02
  Speaker 1: I like people, and I don't want any people to die.
• 36:05
  Speaker 1: But if people are choosing to not have as many
• 36:07
  Speaker 1: babies and we end up with something like four billion,
• 36:10
  Speaker 1: it doesn't sound so bad to me initially to have
• 36:12
  Speaker 1: fewer people that we invest more in. But you all
• 36:14
  Speaker 1: make a pretty good argument about more people being better
• 36:17
  Speaker 1: for a lot of reasons. So let's hear about why
• 36:19
  Speaker 1: we don't want billions of people fewer on this planet.
• 36:23
  Speaker 9: Well, first, I want to hold on that four billion
• 36:25
  Speaker 9: thing for a second, because I think it's important if
• 36:28
  Speaker 9: somebody's listening to this and they're thinking, yeah, let's have
• 36:33
  Speaker 9: some depopulation. And what I want is a future where
• 36:36
  Speaker 9: the world stabilizes at some number like four billion or
• 36:40
  Speaker 9: three billion or two billion. Then that sort of future
• 36:45
  Speaker 9: would fundamentally require the same thing we're talking about here,
• 36:49
  Speaker 9: which is an increase someday in birth rates. Right, the
• 36:52
  Speaker 9: population is not just going to suddenly hang and hold
• 36:55
  Speaker 9: still at eight billion or ten billion, and it's not
• 36:57
  Speaker 9: just going to suddenly hang and hold still at four
• 37:00
  Speaker 9: billion either unless birth rates go back up. So in
• 37:03
  Speaker 9: our book, after the spike, what we're considering is would
• 37:07
  Speaker 9: it be better to have a future of depopulation generation
• 37:10
  Speaker 9: after generation or would it be better instead to have
• 37:13
  Speaker 9: a future of stabilization. And not to hide the ball,
• 37:17
  Speaker 9: we make the case for a future of stabilization. Now
• 37:19
  Speaker 9: we don't say where. That's beyond what anyone could know
• 37:22
  Speaker 9: given the science we have. But let's take four billion.
• 37:25
  Speaker 9: For the world's population to ever stabilize someday at four billion,
• 37:29
  Speaker 9: that means after a period of depopulation, birth rates around
• 37:33
  Speaker 9: the world are going to have to go back up
• 37:35
  Speaker 9: to to and stay there.
• 37:36
  Speaker 2: And I just want to bottom line that to make
• 37:38
  Speaker 2: sure people caught that because you're arguing that if birth
• 37:40
  Speaker 2: rates stay below replacement, we won't just go from eight
• 37:44
  Speaker 2: billion to four billion, we'll go to two billion and
• 37:46
  Speaker 2: one billion and a half a billion, and you just
• 37:47
  Speaker 2: keep going.
• 37:48
  Speaker 5: Down, right.
• 37:49
  Speaker 9: It's you know, when your rocket ship gets to the
• 37:51
  Speaker 9: planet that you want to be on, how do you
• 37:52
  Speaker 9: slow down and stop right? When the global population gets
• 37:57
  Speaker 9: to the size that you want to stabilize that four
• 38:00
  Speaker 9: billion or three billion or whatever, if you want to
• 38:02
  Speaker 9: stay there, then just like at any other size, birth rate,
• 38:05
  Speaker 9: you have to be an average of two. So this
• 38:07
  Speaker 9: is my conciliatory message that we're on the same team here.
• 38:11
  Speaker 9: If you want the size of the population to stabilize somewhere,
• 38:14
  Speaker 9: and we face the same question of how would we
• 38:18
  Speaker 9: ever get back to a birth rate and an average
• 38:20
  Speaker 9: around two. Okay, Now, another question, and it's the one
• 38:24
  Speaker 9: that you asked, which is.
• 38:26
  Speaker 5: Why would we want that?
• 38:27
  Speaker 9: Why would we want the size of the population to
• 38:31
  Speaker 9: stabilize or to avoid depopulation generation after generation? And here's
• 38:37
  Speaker 9: one reason why we think that depopulation matters and that
• 38:40
  Speaker 9: we should want to avoid it, because we're all made
• 38:43
  Speaker 9: better off by sharing the world with more other people,
• 38:46
  Speaker 9: Other people alive alongside us, other people who were live
• 38:49
  Speaker 9: before us. Other people make the discoveries and have the
• 38:52
  Speaker 9: ideas that improve our lives. And other people are where
• 38:55
  Speaker 9: science and knowledge comes from.
• 38:57
  Speaker 1: I like people too.
• 39:00
  Speaker 2: People are awesome.
• 39:01
  Speaker 5: We can drill down on that too. I mean, why
• 39:03
  Speaker 5: are lives better now than a couple centuries ago?
• 39:07
  Speaker 7: You know?
• 39:08
  Speaker 5: Why do we all have shoes on our feet and
• 39:10
  Speaker 5: glasses to correct our vision, plenty to eat, climate controlled work, environment,
• 39:14
  Speaker 5: shorter workdays, a library of literature AI in our pocket?
• 39:18
  Speaker 5: You know, social safety net systems to protect the elderly
• 39:22
  Speaker 5: and disabled. Why our living standards so much higher today
• 39:25
  Speaker 5: than not all that long ago. It's the same sun overhead,
• 39:29
  Speaker 5: it's the same wind blowing, it's the same dirt underneath
• 39:31
  Speaker 5: our feet. But knowledge is the difference. We know better
• 39:34
  Speaker 5: what to do with these things. We know how to
• 39:36
  Speaker 5: extract the minerals from the rocks and make glass and
• 39:39
  Speaker 5: solar panels and computer chips. We know how to farm
• 39:42
  Speaker 5: more efficiently to grow more food, more calories per acre
• 39:45
  Speaker 5: of that dirt, and we know how to do that
• 39:47
  Speaker 5: with less human labor. We know how to make soap
• 39:49
  Speaker 5: to keep us from getting infections. We know how to
• 39:51
  Speaker 5: make antibiotic pills to treat infections, and we have a
• 39:54
  Speaker 5: germ theory of disease so that we know what an
• 39:58
  Speaker 5: infection is. And we know all of these things because
• 40:01
  Speaker 5: of people that came before us. We know better how
• 40:05
  Speaker 5: to organize a kindergarten or a cancer drug trial, or
• 40:07
  Speaker 5: a parliamentary democracy. These these things ideas, discoveries, process improvements, innovations.
• 40:14
  Speaker 5: They are why we all on this call of listening
• 40:17
  Speaker 5: to this podcast get to expect more out of life
• 40:20
  Speaker 5: and better things out of life than people did not
• 40:23
  Speaker 5: all that long ago. This notion is something that economist
• 40:27
  Speaker 5: Paul Romer won a Nobel Prize for in twenty eighteen,
• 40:30
  Speaker 5: and his realization that he sort of formalized in the
• 40:34
  Speaker 5: language of economic math was that an idea isn't scarce
• 40:39
  Speaker 5: in the same way a parcel of land or a
• 40:41
  Speaker 5: physical object like a hammer is scarce. Instead, an idea
• 40:45
  Speaker 5: can be reused and shared endlessly. You know, we've been
• 40:49
  Speaker 5: talking about differential equations. I took differential equations as an
• 40:53
  Speaker 5: undergraduate engineering major. Maybe Kelly or Daniel you had the
• 40:57
  Speaker 5: same textbook as I did, But what I read the
• 40:59
  Speaker 5: words out of that textbook. It didn't cause the words
• 41:02
  Speaker 5: to disappear from your copy of the textbook. Right, We
• 41:05
  Speaker 5: get to reuse these ideas over and over again. And
• 41:08
  Speaker 5: so once Newton or Leibniz invents calculus, or maybe if
• 41:13
  Speaker 5: they didn't live, somebody else would have, then we all
• 41:15
  Speaker 5: get to benefit from that over and over and over again.
• 41:18
  Speaker 5: So ideas and scientific knowledge are a sort of special
• 41:22
  Speaker 5: resource that never gets depleted no matter how much it's used.
• 41:26
  Speaker 5: And that's sort of one of the core reasons why
• 41:29
  Speaker 5: sharing the world with a lot of other people. We're
• 41:31
  Speaker 5: getting to live at a time after a large population
• 41:34
  Speaker 5: has already existed. It's just a huge benefit to us.
• 41:38
  Speaker 2: And it's more than just expanding the population and creating
• 41:41
  Speaker 2: new innovations, right, it's about maintaining our quality of life.
• 41:43
  Speaker 2: We need a certain number of people to keep making
• 41:46
  Speaker 2: t shirts and pencils and teaching our children like the world.
• 41:50
  Speaker 2: Our infrastructure can't survive on a tiny population. But it
• 41:53
  Speaker 2: makes me wonder if we're going to do a ridiculous
• 41:55
  Speaker 2: extrapolation tell us about sort of the numbers of people
• 41:59
  Speaker 2: we expect to have on Earth. If birth rates don't change,
• 42:02
  Speaker 2: how many people we have on Earth in ten years,
• 42:05
  Speaker 2: fifty years, one thousand years, extrapolate all the way out
• 42:08
  Speaker 2: to you know, twenty five thousand years. Are we going
• 42:11
  Speaker 2: to end up with like twenty people on the planet.
• 42:13
  Speaker 9: Okay, we don't know, right, we don't have a crystal ball,
• 42:17
  Speaker 9: but we can make if then assumptions, right, you know,
• 42:20
  Speaker 9: if the birth rates end up like this, then we
• 42:22
  Speaker 9: can say something about how the future would evolve. And
• 42:24
  Speaker 9: so one easy and plausible case is to imagine the
• 42:28
  Speaker 9: worldwide average birth rate of one point five, which is
• 42:31
  Speaker 9: what it is right now in Europe, you know, a
• 42:34
  Speaker 9: little bit less than in the US, and a little
• 42:36
  Speaker 9: bit more than in Canada.
• 42:38
  Speaker 5: So one point five.
• 42:39
  Speaker 9: That's the next generation being twenty five percent smaller, the
• 42:43
  Speaker 9: next generation after that being twenty five percent smaller.
• 42:46
  Speaker 5: Again.
• 42:46
  Speaker 9: So if the world were like that, then every decade
• 42:49
  Speaker 9: we would see the size of the world population fall
• 42:52
  Speaker 9: by ten percent, and every century the size of the
• 42:55
  Speaker 9: world population would fall by two thirds, and that cumulative
• 42:59
  Speaker 9: exponential decay would continue and we could get quite small
• 43:04
  Speaker 9: in just a few hundred years. If instead of it
• 43:06
  Speaker 9: being one point five, it were an average of one
• 43:09
  Speaker 9: like in China today, then you can see the next
• 43:12
  Speaker 9: generation is going to be half the size. The generation
• 43:15
  Speaker 9: after that, the grandchildren's generation is going to be a
• 43:17
  Speaker 9: quarter the size, and so the fall could be very fast. Now,
• 43:21
  Speaker 9: how does all of that play out? How does that,
• 43:23
  Speaker 9: you know, cash out in something big breaking or something
• 43:26
  Speaker 9: breaking down, or not having the discoveries we need, or
• 43:29
  Speaker 9: even the librarians to staff the libraries that we can
• 43:32
  Speaker 9: maintain the knowledge we have. That's hard to know, but
• 43:36
  Speaker 9: we can learn something about it by thinking about sort
• 43:39
  Speaker 9: of comparing more populated places like cities and less populated
• 43:43
  Speaker 9: rural places. You need enough other people around who want
• 43:48
  Speaker 9: and need the same sorts of things that you want
• 43:51
  Speaker 9: and need in order for those things to exist to
• 43:54
  Speaker 9: be feasible to be provided by a government or a
• 43:58
  Speaker 9: business or a nonprofit other people wanting and need. What
• 44:01
  Speaker 9: you want is how you get in. That's true if
• 44:03
  Speaker 9: what you want is well functioning public transportation, because a
• 44:07
  Speaker 9: network of trains and buses can't operate without enough riders.
• 44:10
  Speaker 9: It's true if what you want is a green energy
• 44:13
  Speaker 9: infrastructure built on the work of scientists and engineers and implementers.
• 44:18
  Speaker 9: And it's true for all of us as a whole.
• 44:21
  Speaker 9: If what you need is a vaccine for a novel virus,
• 44:24
  Speaker 9: or a cure for a rare disease. It's the sorts
• 44:27
  Speaker 9: of things that only the niche medical specialization of a
• 44:30
  Speaker 9: big world could produce. And so as there are fewer
• 44:32
  Speaker 9: and fewer of us, we're not going to be able
• 44:35
  Speaker 9: to provide those sorts of discoveries, products, innovation, creation that
• 44:41
  Speaker 9: are only possible with other people. So other people may
• 44:44
  Speaker 9: sometimes be another person may sometimes be your competition, but
• 44:50
  Speaker 9: other people there being other people over the long run,
• 44:52
  Speaker 9: or why things like this can exist and there resource
• 44:55
  Speaker 9: of abundance.
• 44:56
  Speaker 1: Let's take a break, and when we get back, we'll
• 44:58
  Speaker 1: talk about some let's say, less than compassionate methods that
• 45:01
  Speaker 1: have been used in the past to try to improve
• 45:03
  Speaker 1: birth rates, and what are some more ethical options we
• 45:06
  Speaker 1: could consider in the future for improving birth rates. And
• 45:28
  Speaker 1: we're back and we are talking about how the average
• 45:32
  Speaker 1: birth rate globally has fallen below too and the implications
• 45:35
  Speaker 1: of that. So when I think about ways for trying
• 45:39
  Speaker 1: to improve birth rates, the first thing that come to
• 45:42
  Speaker 1: mind are some authoritarian governments who have tried to control
• 45:45
  Speaker 1: birth rates in ways that I'm not super comfortable with.
• 45:48
  Speaker 1: To put it lightly, so let's review some methods that
• 45:51
  Speaker 1: have not worked when countries have tried to improve their
• 45:54
  Speaker 1: birth rates in the past. What do we know does
• 45:55
  Speaker 1: not work well?
• 45:57
  Speaker 5: All of them? All of them.
• 46:00
  Speaker 9: There isn't an example of, you know, government coercion, whether
• 46:05
  Speaker 9: trying to coerce higher birth rates or trying to coerse
• 46:09
  Speaker 9: lower birth rates, you know, resulting in the sort of lasting,
• 46:14
  Speaker 9: big picture, sustainable change to birth rates that could knock
• 46:19
  Speaker 9: the population off of a path of depopulation and onto
• 46:23
  Speaker 9: a path of stabilization. I mean, I want to take
• 46:25
  Speaker 9: a step backwards here. You know, we're making the case
• 46:28
  Speaker 9: that a stabilized future population would be better than global depopulation.
• 46:34
  Speaker 9: We also think that a stabilized population is compatible with
• 46:38
  Speaker 9: commitments to environmental stewardship, to reproductive freedom, and to progressive
• 46:44
  Speaker 9: priorities more broadly, and we want other people to think so,
• 46:47
  Speaker 9: to be a part of this conversation. So we don't
• 46:49
  Speaker 9: want anyone to misunderstand that if somebody chooses to have
• 46:53
  Speaker 9: no children or few children, that's not for anyone else
• 46:56
  Speaker 9: to say whether they're making a mistake. And that's a
• 46:58
  Speaker 9: question of an f starting point. But it might still
• 47:01
  Speaker 9: be that all of us together are making a mistake
• 47:05
  Speaker 9: when we make it hard for people to choose larger
• 47:08
  Speaker 9: families and choose to have children. So you can talk
• 47:12
  Speaker 9: about this and talk about whether stabilization is the future
• 47:14
  Speaker 9: we want without it, you know, necessarily invoking the idea
• 47:19
  Speaker 9: that anyone should be coercing anybody else. Now, that said,
• 47:23
  Speaker 9: it's an important and reasonable thing to worry about, because
• 47:25
  Speaker 9: there have been examples where governments have tried to compel
• 47:29
  Speaker 9: people to have kids they don't want to have, or
• 47:33
  Speaker 9: to compel people not to have kids. So, you know,
• 47:35
  Speaker 9: the classic example that people think about is China's one
• 47:39
  Speaker 9: child policy, where the government of China made it illegal
• 47:44
  Speaker 9: and with harsh and coursive implementation to have what they
• 47:48
  Speaker 9: consider to be too many children. And sure enough, if
• 47:51
  Speaker 9: you look at the birth rate in China over this
• 47:54
  Speaker 9: time period, it fell. However, that doesn't turn out to
• 47:58
  Speaker 9: be evidence that the one policy is why birth rates
• 48:02
  Speaker 9: in China fell. And the surprising fact is that if
• 48:06
  Speaker 9: you take the birth rate in China over time, so
• 48:09
  Speaker 9: make a plot where you know you're looking at the
• 48:11
  Speaker 9: birth rate in nineteen eighty the birth rate nineteen eighty five,
• 48:14
  Speaker 9: the birth rate in nineteen ninety. What you see is
• 48:16
  Speaker 9: the birth rate in China fell overtime while the one
• 48:18
  Speaker 9: child policy was in effect. But if you also look
• 48:21
  Speaker 9: at what happened to birth rates over time in any
• 48:24
  Speaker 9: other middle income developing country that was also undergoing the
• 48:28
  Speaker 9: same sort of increase in living standards, increase in education,
• 48:32
  Speaker 9: specifically increase in female education, you see birth rates falling
• 48:36
  Speaker 9: in basically the same parallel way that that was happening
• 48:39
  Speaker 9: all around the world in countries about that sort of
• 48:43
  Speaker 9: level of socioeconomic development. And so what that tells us
• 48:46
  Speaker 9: is that it probably wasn't the one child policy that
• 48:49
  Speaker 9: was responsible for the big picture decline in birth rates
• 48:51
  Speaker 9: in China. It's not to say that China would have
• 48:53
  Speaker 9: ended up in the exact same place without the one
• 48:55
  Speaker 9: child policy, but somewhere pretty similar. And it's certainly not
• 48:59
  Speaker 9: to say that one child policy didn't do a lot
• 49:02
  Speaker 9: of harm to people's lives in China. But the birth
• 49:04
  Speaker 9: rate is probably where it would have been otherwise.
• 49:07
  Speaker 1: And wasn't there. I can't believe that. I'm forgetting the
• 49:10
  Speaker 1: name of the country and the leader was it child Chescu.
• 49:12
  Speaker 1: Somebody tried to increase birth rates by making birth control
• 49:16
  Speaker 1: unavailable or something like that. Correct my historical inaccuracies, please
• 49:20
  Speaker 1: and tell us that story.
• 49:21
  Speaker 5: No, that's you are correct. So this was Romania, This
• 49:25
  Speaker 5: was nineteen sixty six or sixty seven, Chescu. He implemented
• 49:32
  Speaker 5: decrease seven seventy. And what decrease seven to seventy said
• 49:36
  Speaker 5: was that birth control was no longer going to be
• 49:38
  Speaker 5: available or legal, that abortion was going to be illegal.
• 49:41
  Speaker 5: And just to put this in context, in Romania, prior
• 49:45
  Speaker 5: to that time, abortion was more freely available than it's
• 49:49
  Speaker 5: ever been for like the whole of the United States.
• 49:51
  Speaker 5: So this was a big change in Romania, and that
• 49:55
  Speaker 5: big change overnight did cause birth rates to rise overnight.
• 50:00
  Speaker 5: So you know, you pulled the rugout from people, you
• 50:03
  Speaker 5: change what's available to them, and birth rates did climb
• 50:07
  Speaker 5: between nineteen sixty six and nineteen sixty seven. I think
• 50:09
  Speaker 5: they something like almost doubled.
• 50:11
  Speaker 7: Wow.
• 50:12
  Speaker 5: But in the years that followed, birth rates started tacking
• 50:15
  Speaker 5: back down, and you know, within something like a decade,
• 50:20
  Speaker 5: they've fallen two thirds the way back from where they
• 50:22
  Speaker 5: started prior to the policy, as people made other plans
• 50:27
  Speaker 5: and built their family planning around the new coercive regime,
• 50:31
  Speaker 5: so that policy did a lot of harm to people,
• 50:34
  Speaker 5: and you know, just a lot of harm. I mean,
• 50:37
  Speaker 5: women died, pregnancy became very unsafe. So it was awful,
• 50:42
  Speaker 5: but it was awful without achieving the goal of boosting
• 50:44
  Speaker 5: birth rates super high. And you know, Chescu was overthrown,
• 50:50
  Speaker 5: was lined up against the wall and shot. And so
• 50:53
  Speaker 5: if your formula, and I know this is not anyone
• 50:56
  Speaker 5: on this cause formula, but if it's anybody's formula to
• 50:58
  Speaker 5: try to bring birth rates up by you know, a
• 51:01
  Speaker 5: dictator coursing women to have children they don't want, that's
• 51:05
  Speaker 5: not a sustainable option for anybody, including that dictator.
• 51:09
  Speaker 2: So you want policymakers in the audience to hear that
• 51:12
  Speaker 2: as a cautionary tale.
• 51:14
  Speaker 1: It's a good message. So in either direction trying to
• 51:19
  Speaker 1: push numbers up or push numbers down. We don't have
• 51:21
  Speaker 1: good evidence that it works, and it's incredibly unethical the
• 51:25
  Speaker 1: way it's been done.
• 51:25
  Speaker 5: Yeah, it's I think we have I say, even something
• 51:27
  Speaker 5: a little bit stronger. We have good evidence that it
• 51:29
  Speaker 5: doesn't work.
• 51:30
  Speaker 2: What about other things like trying to provide more childcare
• 51:34
  Speaker 2: or making college cheaper, or more family planning. Aren't there
• 51:38
  Speaker 2: ethical ways we can make it easier for people to
• 51:41
  Speaker 2: have more kids.
• 51:42
  Speaker 5: There are lots of ethical things that we can try
• 51:45
  Speaker 5: and that countries have tried. Unfortunately, the track record there
• 51:49
  Speaker 5: isn't as great as one would hope it would be.
• 51:51
  Speaker 5: So I think we're still still a long way to
• 51:53
  Speaker 5: go to figure out what might work, you know, on
• 51:56
  Speaker 5: this question of making childcare more affordable, more available. You know,
• 52:00
  Speaker 5: if you look to Scandinavian countries, for example, places where
• 52:04
  Speaker 5: college tuition is free, where there's universal health care, where
• 52:08
  Speaker 5: there's childcare that's not only heavily subsidized or free for
• 52:12
  Speaker 5: you know, pre K childcare, but it's also provided like
• 52:16
  Speaker 5: it's available. I don't know what your experiences are, but
• 52:19
  Speaker 5: my experience as a parent is like it's just hard
• 52:22
  Speaker 5: sometimes to organize childcare for when work is on but
• 52:25
  Speaker 5: school is out or you know, summertime. It's a patchwork
• 52:29
  Speaker 5: of things. But even in places where childcare is better organized, free,
• 52:32
  Speaker 5: where tuition is free, where healthcare is more available or
• 52:36
  Speaker 5: free provided socially by the government, these aren't places with
• 52:40
  Speaker 5: high birth rates. And so yes, I think there are
• 52:43
  Speaker 5: things that there's plenty left still to try in the
• 52:47
  Speaker 5: toolkit of what like free liberal societies can do to
• 52:50
  Speaker 5: make life better and easier for parents. But I don't
• 52:54
  Speaker 5: think anybody, not governments, not social scientists, have figured out
• 52:57
  Speaker 5: that what that special sauce is.
• 52:59
  Speaker 9: Yet I want to sort of say that maybe that's
• 53:02
  Speaker 9: not so surprising. I mean, think about, you know, the
• 53:05
  Speaker 9: sort of policies that we hear of, you know, a
• 53:07
  Speaker 9: few thousand dollars baby bonus or something like that. Right,
• 53:10
  Speaker 9: you know, let's do a thought experiment. Would you have
• 53:14
  Speaker 9: agreed to marry somebody other than the person who you
• 53:18
  Speaker 9: married for about five thousand dollars? I don't think very
• 53:22
  Speaker 9: many people are going to say yes to that, right.
• 53:24
  Speaker 2: Our spouse is listening to the podcast, so that question, well.
• 53:28
  Speaker 9: Okay, so it's not a fair task or anonymize. I
• 53:31
  Speaker 9: didn't do my research procedures, right, But I think you know,
• 53:34
  Speaker 9: these are people's biggest decisions forming their family. What's their
• 53:38
  Speaker 9: life story about? What autobiography am I writing?
• 53:41
  Speaker 5: Right?
• 53:41
  Speaker 9: You know, a few thousand dollars will help a lot.
• 53:44
  Speaker 9: And you know, if you ask me or yes, Mike
• 53:47
  Speaker 9: will say that society should do more to help parents,
• 53:50
  Speaker 9: must do more to help parents, right, But when we
• 53:53
  Speaker 9: say do more, we're meaning something a lot bigger, and
• 53:56
  Speaker 9: it just shouldn't be a surprise. If we don't think
• 53:58
  Speaker 9: that a few thousand dollars is going to change who
• 54:01
  Speaker 9: you're going to marry, it's probably not going to change
• 54:03
  Speaker 9: your biggest picture decisions about how to form your family
• 54:07
  Speaker 9: and form your own life story in other ways too,
• 54:10
  Speaker 9: And so yes, by all means, let's support parents, support families.
• 54:14
  Speaker 9: Let's do that, but let's not be surprised when that doesn't,
• 54:18
  Speaker 9: you know, shift us from the path to depopulation the
• 54:21
  Speaker 9: path is stabilization.
• 54:23
  Speaker 1: I was listening to Left, Right and Center the other
• 54:25
  Speaker 1: day and one of the hosts, Sarah Iger, was saying that,
• 54:28
  Speaker 1: you know, one of the reasons population is going down
• 54:31
  Speaker 1: globally is that when women have more reproductive choice and
• 54:34
  Speaker 1: more options in life, they choose to have fewer kids.
• 54:37
  Speaker 1: And one of the things that I love that you
• 54:39
  Speaker 1: all addressed directly in your book was that increases in
• 54:43
  Speaker 1: population size, would you know, in the absence of artificial wombs,
• 54:47
  Speaker 1: have to come from women having more babies, which has
• 54:50
  Speaker 1: a health impact, a career impact, et cetera. So one
• 54:54
  Speaker 1: my question is is it true that when women have
• 54:57
  Speaker 1: more choice, they have fewer children, and that's the mechanism.
• 55:00
  Speaker 1: It sounds like maybe we don't understand that mechanism as well,
• 55:02
  Speaker 1: based on our conversation we've had, and what do you
• 55:05
  Speaker 1: propose as the method for having more babies in a
• 55:08
  Speaker 1: way to do it that sort of distributes this responsibility
• 55:11
  Speaker 1: more evenly.
• 55:13
  Speaker 9: I think that we all have a shared interest in
• 55:17
  Speaker 9: their being future generations, and so that we all need
• 55:21
  Speaker 9: to be pitching in to making there be future generations
• 55:25
  Speaker 9: and sharing and lifting those burdens off of one another.
• 55:28
  Speaker 9: And I think it's no surprise that in a history
• 55:32
  Speaker 9: where we have long put a lot of that burden
• 55:36
  Speaker 9: on a subset of the population, I mean mothers in particular,
• 55:39
  Speaker 9: that we have people saying no, thank you. But because
• 55:43
  Speaker 9: that's been the past, that doesn't necessarily mean that that
• 55:46
  Speaker 9: has to be the future. I mean, sometimes we hear
• 55:49
  Speaker 9: people talking about these conversations about low birth rates, and
• 55:52
  Speaker 9: they act like there's a choice we have to make.
• 55:54
  Speaker 9: Either we can have regressive gender politics that ask more
• 55:59
  Speaker 9: of women, or we can have global depopulation. I think
• 56:03
  Speaker 9: people both on the left and the right start these
• 56:05
  Speaker 9: conversations with the presumption that if we're going to stabilize
• 56:09
  Speaker 9: the population, the extra burden has to fall on to women,
• 56:13
  Speaker 9: and I don't think that's right. I don't think that
• 56:16
  Speaker 9: we should start by asking more for mothers. I think
• 56:18
  Speaker 9: the place to start, or a place to start, is
• 56:20
  Speaker 9: by asking more from fathers. Males can't get pregnant, that's right,
• 56:24
  Speaker 9: But it takes more than nine months to make a
• 56:27
  Speaker 9: new person. It takes decades to raise a child into
• 56:30
  Speaker 9: a new adult. And that means there's plenty of time
• 56:32
  Speaker 9: and plenty to do for men to even things out.
• 56:34
  Speaker 9: Dads can get up at three am to sue the
• 56:37
  Speaker 9: crying baby. They can cook even though they're tired. They
• 56:40
  Speaker 9: can process the laundry and pack the snacks and figure
• 56:43
  Speaker 9: out about the childcare when school is out, and drive
• 56:45
  Speaker 9: to swim lessons and do so much. They can accept
• 56:49
  Speaker 9: the work and the responsibility and being the person who's
• 56:52
  Speaker 9: on call on sick days and summer days, and they
• 56:55
  Speaker 9: can do that for years and years and years and years.
• 56:58
  Speaker 9: You know, I think this is it sounds nice. I
• 57:01
  Speaker 9: mean it's more than just hopeful rhetoric. I think it's
• 57:03
  Speaker 9: a challenge, and we shouldn't consider there to be any
• 57:06
  Speaker 9: sort of guarantee that this is what's going to happen.
• 57:09
  Speaker 9: But the future of birth rates is going to be chosen.
• 57:14
  Speaker 9: Whether or not we depopulate and whether and where we
• 57:17
  Speaker 9: stabilize is are going to come down to the choices
• 57:19
  Speaker 9: that people and especially women make for their lives. That
• 57:22
  Speaker 9: seems pretty clear. And so if we're going to expect
• 57:26
  Speaker 9: people to choose parenting, then there's work that we all
• 57:30
  Speaker 9: need to do to make parenting more attractive, and that
• 57:33
  Speaker 9: starts with lifting and sharing the burdens that for so
• 57:37
  Speaker 9: long have only fallen on.
• 57:39
  Speaker 2: Some of us.
• 57:40
  Speaker 1: I loved reading that part of your book.
• 57:42
  Speaker 2: And is this why you've written a popular book instead
• 57:44
  Speaker 2: of like making this argument to policymakers and within academia.
• 57:49
  Speaker 2: Are you're writing this to the general public to make
• 57:51
  Speaker 2: people aware of this coming issue.
• 57:53
  Speaker 9: Well there's that and the differential equations, but no.
• 57:58
  Speaker 2: That's really your goal in the end, right, This is
• 58:00
  Speaker 2: really just a math lesson This.
• 58:01
  Speaker 9: Is a topic that more people should be talking about,
• 58:04
  Speaker 9: not just you know, more numbers, but a broader set
• 58:07
  Speaker 9: of people. We're at the very beginning of facing up
• 58:11
  Speaker 9: to this challenge. Most people haven't yet come to the
• 58:14
  Speaker 9: terms of the magnitude of what we're facing. But you know,
• 58:17
  Speaker 9: we wouldn't have written this book calling to avoid depopulation
• 58:21
  Speaker 9: if we didn't think it were possible for humanity to
• 58:25
  Speaker 9: change course. Depopulation is the path that we're on, but
• 58:28
  Speaker 9: it's not the inevitable future. People ask us, so, what's
• 58:33
  Speaker 9: your policy recommendation, what legislation would you write? And I
• 58:36
  Speaker 9: think jumping to a policy solution at this point is
• 58:38
  Speaker 9: probably the wrong move. This isn't something that's going to
• 58:41
  Speaker 9: turn around in one presidential term or because of one
• 58:44
  Speaker 9: set of legislative considerations for parents, or you know, a
• 58:47
  Speaker 9: new bill about print to leave. I think we're facing
• 58:51
  Speaker 9: something big, and the first step is many more people
• 58:55
  Speaker 9: sharing a belief that we should want something to change.
• 58:58
  Speaker 9: That's necess Harry precursor. If you're already convinced and you're
• 59:03
  Speaker 9: asking what to do next, I don't think it's advocate
• 59:06
  Speaker 9: for a particular piece of legislation. It's invite more people
• 59:09
  Speaker 9: into the conversation and convince your friends and family and
• 59:12
  Speaker 9: classmates and colleagues that people are fundamentally good for another
• 59:16
  Speaker 9: and that depopulation is not going to get us off
• 59:20
  Speaker 9: the hook for challenges like climate change and our environmental
• 59:24
  Speaker 9: problems that we face. Start a conversation about what could
• 59:29
  Speaker 9: be good about a future in which more people feel
• 59:32
  Speaker 9: like they're able to and support it to choosee parenting.
• 59:35
  Speaker 9: That sort of re orientation to thinking that stabilization might
• 59:38
  Speaker 9: be a good future has got to be the first step.
• 59:41
  Speaker 9: And in the meanwhile, there is a lot of social
• 59:43
  Speaker 9: science to do that we should be building out to
• 59:46
  Speaker 9: better understand what might work, so that once we're able
• 59:49
  Speaker 9: to build the social and the political support for a
• 59:52
  Speaker 9: stabilized future, will know what to do. But there are
• 59:54
  Speaker 9: a lot of minds to change first.
• 59:57
  Speaker 2: Can I end us on an alien's question?
• 59:58
  Speaker 1: Of course, it wouldn't be a DECA episode about it.
• 1:00:02
  Speaker 2: So the fact that we see this trend across so
• 1:00:04
  Speaker 2: many different communities in so many different circumstances makes me wonder,
• 1:00:07
  Speaker 2: naturally if this is something that exists in I don't know,
• 1:00:10
  Speaker 2: all intelligent technological civilizations in the galaxy. And do you
• 1:00:14
  Speaker 2: think maybe what you've done here is stumble on the
• 1:00:16
  Speaker 2: solution to the Fermi paradox.
• 1:00:18
  Speaker 5: I'm so glad you asked that. Wait, wait, wait, wait,
• 1:00:20
  Speaker 5: we need to we need to stop just for a moment.
• 1:00:22
  Speaker 5: You've really made Dean's day. He wants to put the
• 1:00:25
  Speaker 5: Fermi paradox in the book. Don't we ended up putting
• 1:00:28
  Speaker 5: the Fermi paradox in.
• 1:00:29
  Speaker 2: The book, big mistake.
• 1:00:31
  Speaker 7: We cut it.
• 1:00:32
  Speaker 9: There was a cutting room for But I was interviewed
• 1:00:34
  Speaker 9: on a podcast from someone at SETI and I brought
• 1:00:36
  Speaker 9: this up and he was just it was almost like like,
• 1:00:40
  Speaker 9: how how could I say something so silly and smirch
• 1:00:44
  Speaker 9: the podcast? But yeah, I mean, I think it makes
• 1:00:47
  Speaker 9: a lot of sense that, you know, individuals have to
• 1:00:50
  Speaker 9: sacrifice to make the next generation. There are shared public
• 1:00:55
  Speaker 9: benefits of there being a next generation. We're gonna you're
• 1:00:58
  Speaker 9: gonna learn how to control your birth rates, and so
• 1:01:01
  Speaker 9: I do think that this sort of dilemma is probably
• 1:01:06
  Speaker 9: a common one. Now, I am just a humble demographer
• 1:01:11
  Speaker 9: of utra British India.
• 1:01:13
  Speaker 5: I don't you know.
• 1:01:13
  Speaker 9: I can't speak to the larger questions.
• 1:01:16
  Speaker 1: But Dean is glowing right now. Everyone, He's very excited
• 1:01:21
  Speaker 1: to be talked about this. We love it all right,
• 1:01:23
  Speaker 1: Dean and Mike, thank you so much for being on
• 1:01:25
  Speaker 1: the show. This was fascinating and anybody who wants to
• 1:01:27
  Speaker 1: learn more should go grab the book after the spike.
• 1:01:30
  Speaker 5: Thanks very much, guys, Thank you so much.
• 1:01:32
  Speaker 7: Thank you.
• 1:01:40
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