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For the first time in human history, we're not having enough children to keep the world's population from falling.
人类历史上第一次，我们没有足够的孩子来阻止世界人口下降。
And fertility is collapsing fastest not in rich nations but in places like Colombia, Thailand, and Guatemala, upending decades of economic wisdom.
生育率下降最快的国家不是富裕国家，而是哥伦比亚、泰国和危地马拉等国，这颠覆了数十年的经济智慧。
Economist Jesus Fernandez-Villaverde tells EconTalk's Russ Roberts that falling fertility has accelerated sharply over the past decade and defies easy explanation.
经济学家赫苏斯·费尔南德斯·维拉韦德 (Jesus Fernandez-Villaverde) 告诉 EconTalk 的拉斯·罗伯茨 (Russ Roberts)，过去十年生育率急剧下降，而且无法简单解释。
Declining religiosity, smartphones and social media, soaring housing costs, and changing gender norms are popular, but unconfirmed, theories.
宗教信仰、智能手机和社交媒体的下降、住房成本的飙升以及性别规范的变化都是流行但未经证实的理论。
Fernandez-Villaverde offers his own speculative answer, that modern life makes a third child costly and childlessness easy, but admits the puzzle is unsolved.
费尔南德斯-维拉韦德提出了他自己的推测性答案，即现代生活使第三个孩子的成本高昂，而且不生育也很容易，但他承认这个难题尚未解决。
What's clearer is why it matters: as retirees become the dominant voting bloc, spending on pensions and health care crowds out roads, schools, and defense.
更清楚的是它的重要性：随着退休人员成为主导投票群体，养老金和医疗保健支出挤占了道路、学校和国防。
Shrinking economies make public debt harder to service, and fewer births mean fewer scientists, artists, and inventors.
经济萎缩使公共债务更难偿还，出生人数减少意味着科学家、艺术家和发明家减少。
Fascinating – occurs to me that the Barro Becker model may still apply if a gradient approach is used – that is, the middle/lower class has ALSO grown richer/wealthier and so have fewer kids than before (not sure if that is testable) (supported in part by the example of the lady walking her dog at 4 am – that she could now unlike before)
令人着迷——在我看来，如果使用梯度方法，巴罗·贝克尔模型可能仍然适用——也就是说，中/下层阶级也变得更富有/富裕，因此孩子比以前少了（不确定这是否可以测试）（部分得到了凌晨 4 点遛狗的女士的例子的支持——她现在可以与以前不同）
The UN models/predictions are not surprising – simple explanation is a desire for the world to have FEWER kids because the people creating the models/predictions worship “climate change” and consider humans are essentially terrible for the world (unlike Julian Simon) – and the effect on CO2 emissions have much to do with technology invented/created by humans – we use less energy to make what we used to make before)
联合国的模型/预测并不令人惊讶——简单的解释是希望世界拥有更少的孩子，因为创建模型/预测的人崇拜“气候变化”，并认为人类对世界来说本质上是可怕的（不像朱利安·西蒙）——对二氧化碳排放的影响与人类发明/创造的技术有很大关系——我们使用更少的能源来制造我们以前制造的东西）
it seems population growth is the other side of the coin with economic growth.
人口增长似乎是经济增长的另一面。
in the same way, that economic growth does not have to mean bigger McMansions and bulkier cell phones; The consequences of a shrinking population doesn’t mean fewer angry drivers on the highway but perhaps the cure for cancer.
同样，经济增长并不一定意味着更大的豪宅和更笨重的手机；人口减少的后果并不意味着高速公路上愤怒的司机会减少，但也许可以治愈癌症。
anecdotally, I live in the Bay Area and you can just see the direct costs associated with children.
有趣的是，我住在湾区，你可以看到与孩子相关的直接成本。
On top of the onerous housing costs, baumols cost disease means even childcare is Close to prohibitively expensive.
除了繁重的住房费用之外，鲍莫尔斯疾病也意味着即使是儿童保育费用也几乎高得令人望而却步。
my tech worker friends already feel strangled by the outrageous prices we pay for housing and childcare.
我的科技工作者朋友们已经对我们为住房和儿童保育支付的高得离谱的价格感到窒息。
These observations are perfectly aligned with evolutionary biology.
这些观察结果与进化生物学完全一致。
Once children become a net cost center rather than seen as resources, culture becomes the predominant factor in fertility.
一旦儿童成为净成本中心而不是被视为资源，文化就成为生育率的主要因素。
Technological developments over the last 10 years mean that young people around the globe are consuming the same social media and, increasingly, the same culture.
过去十年的技术发展意味着全球的年轻人正在使用相同的社交媒体，并且越来越多地使用相同的文化。
This has two major effects from an evolutionary perspective.
从进化的角度来看，这有两个主要影响。
The first is the intensification of female hypergamy from a local to global scale, where perceptions of what constitutes an acceptable partner are distorted not only by the absolute upper tail of the societal distribution but also by fabricated realities propagated through social media.
首先是女性一夫多妻制从地方到全球范围的加剧，对可接受伴侣的看法不仅被社会分布的绝对上层尾巴所扭曲，而且还被通过社交媒体传播的捏造现实所扭曲。
The second impact is also centered around female intrasexual competition.
第二个影响也集中在女性性内竞争上。
Elite women, who once could suppress the fertility of lower-status competitors only at the local level, can now disseminate their message globally, sub-consciously or intentional.
精英女性曾经只能在地方层面压制地位较低的竞争者的生育能力，现在却可以在全球范围内无意识或有意地传播她们的信息。
The guest’s point about affordability is secondary to perception.
客人关于负担能力的观点是次要的。
It’s precisely _relative_ affordability that’s driving fertility rates down.
正是相对的负担能力导致生育率下降。
In absolute terms, people in middle-income countries are generally far wealthier than their counterpart decades ago and as compared to those in much poorer countries today.
从绝对值来看，中等收入国家的人民普遍比几十年前的人民富裕得多，也比当今贫困得多的国家的人民富裕得多。
The desire to maintain a relative standard of living in the context of children is the real factor.
真正的因素是维持儿童相对生活水平的愿望。
Source: Research by Danielle Sulikowski and David Buss.
资料来源：Danielle Sulikowski 和 David Buss 的研究。
I’m not sure why my comment was caught by the spam filter.
我不知道为什么我的评论被垃圾邮件过滤器捕获。
I’m summarizing and drawing upon the research of renowned psychologists David Buss and Dani Sulikowski.
我正在总结并借鉴著名心理学家大卫·巴斯和丹尼·苏利科斯基的研究。
The seeming failings of Barro Becker are well explained by contending with the technological developments of the last decade through the lens of evolutionary biology.
巴罗·贝克尔表面上的失败可以通过进化生物学的视角应对过去十年的技术发展得到很好的解释。
Essentially, the instincts of young people when it comes to mate selection and family planning, as a function of the hospitability of the environment, have become maladaptive in the wake of the global reach of modern social media.
从本质上讲，随着现代社交媒体的全球影响力，年轻人在择偶和计划生育方面的本能，作为环境好客的函数，已经变得适应不良。
What would have been a cautious level of hypergamy has been distorted by the upper tail of the societal distribution and, frankly, outright fabrications.
原本谨慎的一夫多妻制已经被社会分布的上尾部分以及坦率地说是彻头彻尾的捏造所扭曲。
Dani Sulikowski, in particular, points to evidence that messaging used in local female intrasexual competition, a method by which high-status women suppress the fertility of lower-status folks, has now spread globally.
丹尼·苏里科夫斯基(Dani Sulikowski)特别指出，有证据表明，当地女性性内竞争中使用的信息——一种地位较高的女性压制地位较低的女性的生育能力的方法——现已在全球传播。
Indeed, adding the accessibility of smartphones is a much better predictor of fertility than wealth alone.
事实上，增加智能手机的使用比单纯的财富更能预测生育率。
[Comments are caught by the spam filter every time you use a new nickname/email-address combo.
[每次您使用新的昵称/电子邮件地址组合时，垃圾邮件过滤器都会捕获评论。
Hence, both your comments in this thread were caught by the spam filter.–Econlib Ed.]
因此，您在该帖子中的评论都被垃圾邮件过滤器捕获。–Econlib Ed.]
I was born in 1949 in Kansas City, MO.
我 1949 年出生于密苏里州堪萨斯城。
In other words, a relatively normal part of the country.
换句话说，这个国家相对正常的地区。
My parents purchased a Cape Cod in Prairie Village, KS, a typical postwar middle class suburb, in 1951 for $12,500.
1951 年，我的父母在堪萨斯州 Prairie Village（典型的战后中产阶级郊区）以 12,500 美元购买了一辆 Cape Cod。
It had two bedrooms and an unfinished basement and second story.
它有两间卧室和一个未完工的地下室和二楼。
Adjusted for inflation, that would be around $160,000 today.
考虑到通货膨胀因素，今天的价格约为 160,000 美元。
My father had a job as a buyer for a department store.
我父亲在一家百货公司担任采购员。
My mother was a housewife until 1973.
我的母亲在 1973 年之前一直是一名家庭主妇。
In a normal area of the country, such a house could still be purchased for $160,000.
在国内正常地区，这样的房子16万美元还是可以买到的。
Those who are dispirited by the housing crisis are suffering from expectation inflation, because the size of the average house has increased significantly since then.
那些因住房危机而沮丧的人正在遭受预期通胀的困扰，因为自那时以来，平均房屋面积已大幅增加。
I have a couple of friends who have had 12 children.
我有几个朋友，他们有 12 个孩子。
I, like my parents, had 4.
我和我的父母一样，有 4 个孩子。
Two generations down the line, we have acquaintances with several children who send them to junior college classes while still in high school, and who get a 2- or 4-year degree with minimal debt.
两代人之后，我们认识了几个孩子，他们在高中时就把他们送到专科学校，并以最少的债务获得了 2 年或 4 年制学位。
Or they go to a local trade school, and graduate with a middle-income job and no debt.
或者他们去当地的一所贸易学校，毕业时找到一份中等收入的工作，没有债务。
This is a problem of attitude inflation, prestige inflation, or locality preference.
这是一个态度膨胀、声望膨胀或地方偏好的问题。
In normal areas of the country, anyone suffering from the problems described regarding children is experiencing an artifact of media located largely in abnormal areas of the country.
在该国的正常地区，任何遭受所描述的儿童问题的人都正在经历主要位于该国非正常地区的媒体假象。
Since it is an artifact, I suspect the problem will self-correct in time.
由于它是一个工件，我怀疑问题会及时自我纠正。
Either that, or read Huxley’s Brave New World.
或者，或者阅读赫胥黎的《美丽新世界》。
This conversation corrected many demographic misconceptions of mine.
这次谈话纠正了我对人口统计学的许多误解。
I always took U.N.
我总是参加联合国。
future population projections as accurate as could be expected and I learned from this conversation that they are inherently flawed.
未来的人口预测与预期一样准确，但我从这次谈话中了解到，它们本质上是有缺陷的。
I had no idea whatsoever of the problematics of having a third-child in the present American reality.
我完全不知道在当前的美国现实中生第三个孩子会带来什么问题。
I had no idea of middle- income families’ extreme democratic decline.
我不知道中等收入家庭的民主极度衰落。
I did know the historic reversal of wealthier American (USA) families having more children and the poor suffering more from broken families.
我确实知道历史性的逆转：较富裕的美国家庭拥有更多的孩子，而穷人则因家庭破裂而遭受更多痛苦。
Still there are in my opinion great omissions and mistaken value-judgments in the conversation.
我认为谈话中仍然存在很大的遗漏和错误的价值判断。
No consideration whatever is given to the specific effects of religion, nationality, political ideology on the global demographic situation.
没有考虑宗教、国籍、政治意识形态对全球人口状况的具体影响。
The championing of not marrying and not having children seems to be woefully unaware of the effect of this on societal well-being and personal life meaningfulness.
可悲的是，倡导不结婚和不生孩子的人似乎没有意识到这对社会福祉和个人生活意义的影响。
Consider for instance the one place I know most about Israel.
以我对以色列最了解的一个地方为例。
How can you understand the positive demographics of Israel without understanding the effect of the Shoah and the Israeli-Arab or now Israeli-Muslim conflicts on its demography?
如果不了解大屠杀、以色列-阿拉伯冲突或现在的以色列-穆斯林冲突对其人口结构的影响，你怎么能理解以色列积极的人口结构呢？
This is a fascinating topic.
这是一个令人着迷的话题。
To share a few things.
分享一些事情。
* There’s a video, “South Korea is Over”, which points out that their numbers are so low that short of some robot or immigration miracle, South Korea *CAN NOT SURVIVE* the next 30 years.
* 有一个视频，“韩国已经结束”，其中指出，韩国的人数如此之低，如果没有机器人或移民奇迹，韩国在未来 30 年*无法生存*。
The point the video makes is that, even if magically every woman had 2-3 children in the next 2 years, those children will not become tax paying adults for 25 years and that the country can not make it through those 25 years with the population demographics they have in terms of the number of tax paying adults available to support the society.
该视频的要点是，即使每个妇女在未来 2 年内神奇地生出 2-3 个孩子，这些孩子在 25 年内也不会成为纳税成年人，而且以可用于支持社会的纳税成年人数量来衡量，该国无法度过这 25 年。
* In around 2005, there was a trivia program on Japanese TV where they’d make outrageous claims then cut to commercial, after the break they’d explain.
* 2005年左右，日本电视台有一档问答节目，他们会提出一些离谱的言论，然后切入广告，在休息后他们会解释。
The claim was “In the year 3000 the population of Japan will be ….
声称是“到 3000 年，日本的人口将是……”。
7 people”.
7人”。
After the break they interviewed the government person in charge of tracking population and he was like “Yes, that is what the current numbers project if nothing changes”.
休息后，他们采访了负责追踪人口的政府负责人，他说：“是的，如果没有任何变化，这就是当前的数字预测”。
They then joking encouraged you to “get busy tonight for Japan”
然后他们开玩笑鼓励你“今晚为日本忙碌起来”
* One thing the interview didn’t really cover is how fast the decline will happen, assuming nothing changes.
* 采访没有真正涵盖的一件事是，假设没有任何变化，下降的速度将会有多快。
As Mr. Fernández-Villaverde pointed out, there is momentum, old people don’t die immediately so the population is not yet shrinking.
正如费尔南德斯-维拉韦德先生指出的那样，势头强劲，老年人不会立即死亡，因此人口尚未减少。
But, that’s largely ignoring what will actually happen once the momentum ends.
但是，这在很大程度上忽略了一旦势头结束实际会发生什么。
Go look at graphs and you can see the curve looks like a roller coaster, diving down steep once that upward momentum ends.
看看图表，你会发现曲线看起来就像过山车，一旦上升势头结束，就会急剧下降。
This was a valuable episode.
这是一个有价值的插曲。
I learned a lot.
我学到了很多。
This is a fascinating topic.
这是一个令人着迷的话题。
Let’s have more coverage.
让我们有更多的报道。
Fantastic podcast, I hope you have this guest on many more times!
很棒的播客，我希望您能多次邀请这位嘉宾！
I was hoping the next discussion with him could dive more deeply into how these demographic shifts impact Social Security and other welfare programs.
我希望与他的下一次讨论能够更深入地探讨这些人口变化如何影响社会保障和其他福利计划。
You both discussed it briefly, but it would be helpful to see some specific, financial projections and to understand if (like the discussion about the UN projections and climate accounting) official budget projections are relying on outdated demographic models.
你们都对此进行了简短的讨论，但了解一些具体的财务预测并了解（如关于联合国预测和气候核算的讨论）官方预算预测是否依赖于过时的人口模型将很有帮助。
Would like to hear Part 2, the economic impact of falling population levels.
想听听第二部分，人口数量下降的经济影响。
Is the entire capitalist model built on the presumption of ever expanding markets aka populations?
整个资本主义模式是否建立在市场（即人口）不断扩大的假设之上？
How could existing entitlements even exist in 20-50 years if populations fall enormously?
如果人口大幅下降，20-50年后现有的权利怎么可能存在？
who will provide senior care, health care, etc if the ratio of young to old continues to decline?
如果年轻人与老年人的比例持续下降，谁来提供养老、医疗保健等？
it was once presumed that countries like the US could import labor via immigration but if global fertility falls below replacement rate then who would the US import?
曾经有人认为，像美国这样的国家可以通过移民进口劳动力，但如果全球生育率低于替代率，那么美国会进口谁？
“No, so, basically, the idea is, how many Einsteins you are going to have in a population?
“不，所以，基本上，这个想法是，人口中会有多少个爱因斯坦？
Well, to some degree, it depends on how many children you have.
嗯，在某种程度上，这取决于你有多少个孩子。
And, when you have a much smaller population, you are going to have a lower chance of having a top person.” It is also important which population.
而且，当人口少得多时，出现顶尖人物的机会就会降低。”哪个人群也很重要。
For example, it could be that people who live in free countries are more likely to produce more top people.
例如，生活在自由国家的人们更有可能培养出更多的顶尖人才。
To use a blunt instrument: Nobel Prize Winners:
使用钝器： 诺贝尔奖获得者：
Group Share of world population Nobel laureates Share of Nobel laureates Multiple of “fair share”
群体 占世界人口的比例 诺贝尔奖获得者 诺贝尔奖获得者的比例 “公平份额”的倍数
United States ~4.2% (≈342M) 427 ~42% ~10×
美国 ~4.2% (≈342M) 427 ~42% ~10×
United Kingdom ~0.85% (≈69M) 144 ~14% ~16×
英国 ~0.85% (≈69M) 144 ~14% ~16×
This is a fascinating episode.
这是一个令人着迷的情节。
Mr.Fernandez-Villaverde is a charming and entertaining guest, and his humility is refreshing.
费尔南德斯-维拉韦德先生是一位迷人而有趣的客人，他的谦逊令人耳目一新。
I knew that fertility rates have been dropping – Elon Musk has raised concerns about this for years, but I was shocked at the degree and rate of decline.
我知道生育率一直在下降——埃隆·马斯克多年来一直对此表示担忧，但我对下降的程度和速度感到震惊。
I have so many questions regarding why having children has gone out of fashion.
关于为什么生孩子已经过时，我有很多疑问。
Raising children, and subsequently enjoying grandchildren, seems to me the best part of life.
在我看来，抚养孩子并享受孙子孙女似乎是生命中最美好的部分。
This made me think of the Econtalk episode with L.A.
这让我想起了 L.A. 的 Econtalk 节目。
Paul on the Vampire Problem ….
保罗谈吸血鬼问题……
having children is one of those transformative experiences that can’t be understood unless you’ve been through it.
生孩子是一种变革性的经历，除非你亲身经历过，否则你无法理解它。
This was a great episode.
这是一个很棒的插曲。
Why is the collapse in fertility so rarely mentioned in debates over immigration?
为什么在关于移民的争论中很少提及生育率的崩溃？
Doesn’t this explain why Europe, Canada, and (until recently) the US have liberalized immigration policies?
这难道不能解释为什么欧洲、加拿大和（直到最近）美国都放宽了移民政策吗？
Of course with fertility rates collapsing all over the world, immigration is not a long term solution.
当然，随着世界各地生育率的大幅下降，移民并不是一个长期的解决方案。
But surely, if we’re to maintain social programs for the aging population, increased immigration has to be part of the solution at least in the short term.
但可以肯定的是，如果我们要维持针对老龄化人口的社会计划，至少在短期内，增加移民就必须成为解决方案的一部分。
The low population scenarios that could occur in 200 or 400 years if behavior doesn’t change are the flip sides of a tongue-in-cheek paper published in 1960 (citation below) that modeled an infinite human population in November 2026.
如果行为不改变，200 或 400 年后可能出现的人口减少情景与 1960 年发表的一篇半开玩笑的论文（引文如下）相反，该论文模拟了 2026 年 11 月的无限人口。
The model was fairly accurate till the mid 1990s, but behavior has changed.
该模型在 20 世纪 90 年代中期之前还相当准确，但行为已经发生了变化。
Population is now larger than it has ever been, but far from infinite.
现在的人口比以往任何时候都多，但远非无限。
The value of these scenarios may be to expand our imaginations about the long-term consequences of current trends.
这些情景的价值可能在于扩大我们对当前趋势的长期后果的想象力。
Of course, a steady or shrinking population will have different challenges than the growing populations of the last several decades.
当然，人口稳定或减少将面临与过去几十年人口增长不同的挑战。
But there will be new technologies, and presumably more Albert Einsteins.
但将会有新技术，并且可能还会有更多的阿尔伯特·爱因斯坦。
It may be worth noting that current population levels, densities, technologies, and consumption patterns are relatively recent and we mostly make it up as we go, sometimes for the better.
值得注意的是，当前的人口水平、密度、技术和消费模式都是相对较新的，我们大多是边走边弥补，有时是为了更好。
Toward the end of the conversation Jesús Fernández-Villaverde said “Now, it’s a scenario .
在谈话即将结束时，赫苏斯·费尔南德斯-维拉韦德说道：“现在，这是一个场景……。
A lot of things are going to counterbalance, so I’m not saying that we are–and I really don’t want to be on the side that says, ‘We are running into extinction,’ because I don’t think that’s the case.
很多事情都会相互抵消，所以我并不是说我们是这样的——而且我真的不想站在说“我们正在走向灭绝”的一边，因为我认为情况并非如此。
But, I don’t think that people get the point: This is not going down a little bit and stabilizing.
但是，我认为人们没有明白这一点：这并没有一点点下降并趋于稳定。
At the current scenario, it’s a continuous drop.”
从目前的情况来看，这是持续下降。”
It will be a continuous drop if behavior doesn’t change, and depending on how behavior changes.
如果行为不改变，这将是持续下降，并且取决于行为如何变化。
It could change to produce a more or less steep drop, or to roughly stabilize population.
它可能会发生变化，导致或多或少的急剧下降，或者大致稳定人口。
Future behavior is up to current young and future people to make their own fertility choices.
未来的行为取决于当前的年轻人和未来的人们做出自己的生育选择。
And these choices will likely vary by regional conditions, culture and technologies that do not yet exist.
这些选择可能会因地区条件、文化和尚不存在的技术而异。
According to a Danish proverb (not Yogi Berra) “It is difficult to make accurate predictions, especially about the future.” Yogi Berra is often falsely given credit for this and other things he didn’t say, which he humorously acknowledged in the subtitle of his 1999 book: “I really didn’t say everything I said.”
根据丹麦谚语（不是尤吉·贝拉），“很难做出准确的预测，尤其是对未来的预测。”尤吉·贝拉 (Yogi Berra) 经常因为这件事和其他他没有说的事情而受到错误的认可，他在 1999 年书的副标题中幽默地承认了这一点：“我确实没有说出我所说的一切。”
Heinz von Foerster, P.
海因茨·冯·福斯特，P.
M.
M。
Mora and L.
莫拉和 L.
W.
W.
Amiot (November 1960).
阿米奥特（1960 年 11 月）。
“Doomsday: Friday, 13 November, A.D.
“世界末日：公元 11 月 13 日星期五
2026.
2026 年。
At this date human population will approach infinity if it grows as it has grown in the last two millennia”.
到那时，如果人口数量像过去两千年那样增长的话，将接近无穷大。”
Science .
科学 。
132 (3436): 1291–1295.
132（3436）：1291-1295。
https://www.science.org/doi/10.1126/science.132.3436.1291
https://www.science.org/doi/10.1126/science.132.3436.1291
My own personal theory is that pornography is the single most important reason for the drop in fertility.
我个人的理论是，色情内容是生育率下降的最重要原因。
It has had a fundamental (and bad) impact on human intimacy, and people (especially young people) are having less sex than ever.
它对人类的亲密关系产生了根本性的（而且是坏的）影响，人们（尤其是年轻人）的性行为比以往任何时候都少。
This site uses Akismet to reduce spam.
该网站使用 Akismet 来减少垃圾邮件。
Learn how your comment data is processed.
了解您的评论数据是如何处理的。
Additional ideas and people mentioned in this podcast episode:
本播客节目中提到的其他想法和人物：
A few more readings and background resources:
更多阅读材料和背景资源：
More related EconTalk podcast episodes, by Category:
更多相关的 EconTalk 播客剧集，按类别：
* As an Amazon Associate, Econlib earns from qualifying purchases.
* 作为亚马逊合作伙伴，Econlib 通过符合条件的购买赚取收入。
Intro.
简介。
[Recording date: September 10, 2026.]
[记录日期：2026年9月10日。]
Russ Roberts: Today is September 10th, 2026, and my guest is Jesús Fernández-Villaverde, the Howard Marks Presidential Professor of Economics at the University of Pennsylvania.
拉斯·罗伯茨：今天是 2026 年 9 月 10 日，我的嘉宾是宾夕法尼亚大学霍华德·马克斯经济学总统教授 Jesús Fernández-Villaverde。
Our topic for today is fertility and demography, based on a recent paper he wrote--he coauthored--with Patrick Norrick, and that paper is "Terra Incognita: The Economics of a Shrinking World," a paper I found to be honest, shocking in its claims, but the claims are mostly facts.
我们今天的主题是生育率和人口学，基于他最近与帕特里克·诺里克（Patrick Norrick）合着的一篇论文，那篇论文是《未知的土地：缩小世界的经济学》，我发现这篇论文的说法很诚实，令人震惊，但这些说法大多是事实。
So, put on your seatbelt, folks.
所以，请系好安全带，伙计们。
It's going to be an interesting ride.
这将是一次有趣的旅程。
Russ Roberts: We're going to start with some basics.
Russ Roberts：我们将从一些基础知识开始。
I told Jesus before we started, this is, I think, the first episode on demographics that we've ever had on EconTalk, so we'll make sure that we get you up to speed before we get you to some of the more complex ideas.
在我们开始之前，我告诉 Jesus，我认为这是我们在 EconTalk 上播放的关于人口统计的第一集，因此我们将确保在让您了解一些更复杂的想法之前先让您了解最新情况。
I want to start with the Total Fertility Rate, sometimes abbreviated as TFR, the total fertility rate.
我想从总生育率开始，有时缩写为 TFR，即总生育率。
You will hear that it needs to be at least 2.1 to be at replacement level.
您会听说它至少需要 2.1 才能达到替换级别。
As we'll learn from this conversation, that's not true in general.
正如我们将从这次对话中了解到的那样，一般情况下情况并非如此。
It could be true in specific cases.
在特定情况下这可能是正确的。
But, what is the total fertility rate?
但是，总和生育率是多少？
Jesús Fernández-Villaverde: Okay.
赫苏斯·费尔南德斯-维拉韦德：好的。
So, we take a population, let's say the United States, and we measure how many children women have on average, and that's total fertility rate.
所以，我们以美国为例，我们测量女性平均有多少个孩子，这就是总生育率。
Now, there's a couple of subtleties that you don't need to worry much.
现在，有一些微妙之处您无需太担心。
But, when we say that the total fertility rate in the United States right now is 1.57, what it means is that women will have, on average, 1.57 children over their lifetimes.
但是，当我们说美国目前的总生育率为1.57时，这意味着女性一生中平均会生育1.57个孩子。
Russ Roberts: But that's a strange thing because many of the women in our conversation are still in their childbearing years.
拉斯·罗伯茨：但这很奇怪，因为我们谈话中的许多女性仍处于育龄期。
So, literally, if I understood your paper--or the video that I'll also link to--correctly, childbearing years--there's exceptions, but they're small in number and its impact on the total childbearing years are 15 to 45, approximately.
因此，从字面上看，如果我正确地理解了您的论文（或者我还将链接到的视频），即育龄期，则存在例外情况，但例外情况很少，并且对总育龄期的影响大约为 15 到 45 年。
So, to calculate the TFR, we look at how many children women of 15 are having, 16, 17, 18, 19, all the way up through 45, even though there are many women we're interested in who are 23.
因此，为了计算 TFR，我们会查看 15 岁、16、17、18、19 一直到 45 岁的女性有多少个孩子，尽管我们感兴趣的女性中有很多是 23 岁。
And we're assuming, when we calculate that TFR, that total fertility rate, that a woman today who is 30, say, will have the same experience when she's 31, 32, etc., that women of that age are now.
当我们计算 TFR（总生育率）时，我们假设今天 30 岁的女性在 31、32 等岁时会有与现在那个年龄段的女性相同的经历。
Is that a correct way to summarize it?
这是一个正确的总结方式吗？
Jesús Fernández-Villaverde: Yes, exactly.
Jesús Fernández-Villaverde： 是的，完全正确。
So, there is a similar concept called Completed Fertility Rate.
因此，有一个类似的概念，称为完成生育率。
Completed Fertility Rate--we are in 2026 now--so, we look at women who are 46 today, and we ask, how many children did they actually have over their lifetime?
完成生育率——现在是 2026 年——所以，我们看看今天 46 岁的女性，我们会问，她们一生中实际上生了多少个孩子？
Now, the problem of completed fertility rate is that it comes with a big lag, by definition.
现在，完成生育率的问题是，从定义上看，它存在很大的滞后性。
Jesús Fernández-Villaverde: A lag, because it means that, for instance, we are not going to be able to tell the fertility rates of women born around 2000 until 2046.
Jesús Fernández-Villaverde：这是一个滞后，因为这意味着，例如，我们在 2046 年之前无法得知 2000 年左右出生的女性的生育率。
So, the big question is, how far away is total fertility rates for completed fertility rates?
那么，最大的问题是，总和生育率与完成生育率还有多远？
If we go to the historical record, turns out to be the case they are not that different.
如果我们查阅历史记录，事实证明它们并没有那么不同。
Jesús Fernández-Villaverde: Historically.
Jesús Fernández-Villaverde：历史上。
That's fair enough.
这很公平。
It's fair enough.
这很公平。
But, historically, they're not that different.
但是，从历史上看，它们并没有那么不同。
Russ Roberts: Yeah.
拉斯·罗伯茨：是的。
One of the things I learned from your work is that things can be very different very quickly.
我从你的工作中学到的一件事是，事情可能很快就会发生很大的变化。
Alfred North Whitehead, I think, said, 'Nature doesn't make jumps,' meaning that things are somewhat continuous.
我认为阿尔弗雷德·诺斯·怀特海德说过，“自然不会跳跃”，意思是事物在某种程度上是连续的。
But, in this problem, as I said, it's kind of shocking.
但是，正如我所说，在这个问题上，这有点令人震惊。
Russ Roberts: So, let's talk about the Replacement Level of the total fertility rate of 2.1.
拉斯·罗伯茨：那么，我们来谈谈总和生育率的更替水平2.1。
Now, I want to start with the naive argument, if you would, to explain to our listeners: Why is 2.1 the number that many people were taught is replacement?
现在，我想从一个幼稚的论点开始，如果你愿意的话，向我们的听众解释一下：为什么 2.1 是许多人被教导的数字是替换？
Why is that a reasonable starting place?
为什么这是一个合理的起点？
We'll then talk about why it's probably not exactly right.
然后我们将讨论为什么它可能不完全正确。
Jesús Fernández-Villaverde: Okay.
赫苏斯·费尔南德斯-维拉韦德：好的。
So, this is very easy.
所以，这很容易。
Imagine that you have 100 women in the population.
想象一下，人口中有 100 名女性。
To keep population constant over time, you will need another 100 women in the next generation.
为了保持人口数量长期稳定，下一代还需要 100 名女性。
So, 100 women in this generation, 100 women in the next generation.
所以，这一代有 100 名女性，下一代有 100 名女性。
So, how many children these 100 women need to have?
那么，这100名女性需要生多少个孩子呢？
Well, they need to have around 210.
嗯，他们需要大约 210 个。
The reason is the following.
原因如下。
Nature, in the absence of any type of selective abortion, implies that we tend to have around 5% more boys than girls.
在没有任何类型的选择性堕胎的情况下，大自然意味着男孩的数量往往比女孩多 5% 左右。
This is probably evolutionary reasons.
这可能是进化的原因。
Testosterone basically means that a lot of teenagers do stupid things and get themselves killed.
睾丸激素基本上意味着许多青少年会做愚蠢的事情并导致自杀。
Testosterone also means that men die of illnesses earlier.
睾丸激素还意味着男性会更早死于疾病。
So, evolutionary forces have probably forced us to be 1.05.
所以，进化的力量可能迫使我们变成 1.05。
That means that of these 210 children, around 106 are going to be boys, around 107; 103 are going to be girls.
这意味着这 210 名儿童中，大约 106 名是男孩，大约 107 名； 103将是女孩。
Now, of these 103 girls, not all of them will reach their fertility age.
现在，这103名女孩中，并非所有人都达到了生育年龄。
They will die in infant times, they will die as teenagers, they will die in the middle of the fertility age.
他们会在婴儿时期死亡，在青少年时期死亡，在生育年龄中期死亡。
In a country like the United States, the number of women that will survive is around 98%.
在美国这样的国家，女性的存活率约为98%。
So, of the 103 girls that are born, 100 move to be mothers themselves, which, on average, will have 210 children, and that way you keep 100 again and again and again.
因此，在出生的 103 个女孩中，有 100 个成为了母亲，平均而言，她们将生下 210 个孩子，这样一来，您就可以一次又一次地保留 100 个孩子。
So, that's why 200 comes.
所以，这就是200来的原因。
Russ Roberts: So, 2.1 is the number most people think of as what it takes to keep a population stable, constant at that level.
拉斯·罗伯茨：所以，大多数人认为 2.1 是保持人口稳定、恒定在该水平所需的数字。
Just as an example, I think I have this right--you'll correct me--in the 1950s, the total fertility rate for the world was about 5.
举个例子，我想我有这个权利——你会纠正我的——在 20 世纪 50 年代，世界总生育率约为 5。
So, of course, every year, the population was growing--the world population--as it has continued to do until recently.
因此，当然，人口——世界人口——每年都在增长，直到最近一直如此。
And, we'll get to that in a second.
我们稍后会讨论这个问题。
It's one of the more remarkable findings that you share.
这是您分享的更引人注目的发现之一。
But, explain why 2.1, which seems like a totally defensible number, is probably not the right number for some other countries for keeping a stable population.
但是，解释一下为什么 2.1 这个看起来完全合理的数字，对于其他一些国家来说可能不是保持人口稳定的正确数字。
Jesús Fernández-Villaverde: Exactly.
赫苏斯·费尔南德斯-维拉韦德：没错。
First, you have selective abortions.
首先，你有选择性堕胎。
In countries like China and India, a lot of girls are aborted, so you have that the sex ratio at birth is much higher.
在中国和印度等国家，很多女孩都堕胎，因此出生性别比要高得多。
It's 110, 115.
是110、115。
So, when we say--
所以，当我们说——
Jesús Fernández-Villaverde: Male to female, yes.
Jesús Fernández-Villaverde：男变女，是的。
So, when we see that there are 10 million children being born in China, we are not talking about 5 million and 5 million.
所以，当我们看到中国有1000万儿童出生时，我们不是在谈论500万、500万。
We are talking about a much more skewed difference, maybe five and a half million versus four and a half million.
我们正在谈论一个更加扭曲的差异，也许是五百万对四五十万。
The second thing is, in developing economies, a lot of the girls do not reach their fertility age, the fertile age, because they die before.
第二件事是，在发展中经济体，很多女孩没有达到生育年龄，因为她们之前就去世了。
When you put these two things together, you can easily get that replacement rates are much higher: 2.3, 2.4.
当你把这两件事放在一起时，你可以很容易地得到替代率要高得多：2.3，2.4。
In some Sub-Saharan countries, it can be as high as 2.5.
在一些撒哈拉以南非洲国家，该值可能高达 2.5。
I want to emphasize, Russ, I'm not inventing this.
我想强调，拉斯，这不是我发明的。
I promise that if you take any undergraduate textbook in demography, this is Chapter 2.
我保证，如果你选一本人口学本科教材，这就是第二章。
This is as mainstream, conventional a statement as you can get.
这是你所能得到的最主流、最传统的说法。
For some reason, most people do not seem to have reached to Chapter 2 of Introduction to Demographics 101.
由于某种原因，大多数人似乎没有读到人口统计学导论 101 的第 2 章。
So, I promise, this is conventional.
所以，我保证，这是传统的。
Russ Roberts: Great.
拉斯·罗伯茨：太好了。
Now, what has changed with--you make a claim in your paper that something has happened in the last few years that has never happened in probably, almost certainly, in the hundreds of millions of--at least thousands of years of recorded history.
现在，发生了什么变化——你在论文中声称，过去几年发生了一些事情，而这些事情可能，几乎可以肯定，在数亿——至少数千年有记录的历史中从未发生过。
Jesús Fernández-Villaverde: Yeah.
赫苏斯·费尔南德斯-维拉韦德：是的。
So, when you take account of the effects I was mentioning you before, the replacement rate for the whole planet is around 2.2.
所以，当你考虑到我之前提到的影响时，整个地球的更替率约为 2.2。
And right now, the total fertility rate of the planet is probably around 2.18, 2.17.
而现在，地球的总生育率大概在2.18、2.17左右。
Means that for the first time in our histories as species, we are below replacement rate.
这意味着，在我们作为物种的历史上，我们第一次低于更替率。
We are not having enough children to keep population constant in the long run.
从长远来看，我们没有足够的孩子来保持人口稳定。
Now, that doesn't imply that population has stopped growing.
现在，这并不意味着人口已经停止增长。
There is something called momentum, and momentum is very easy to explain.
有一种东西叫做动量，动量很容易解释。
Imagine that you have two parents, and they only have one child, but the parents have not died yet, so the population of that family has grown from two to three.
想象一下，你有两个父母，他们只有一个孩子，但父母还没有去世，所以那个家庭的人口从两个增加到了三个。
That's momentum.
这就是势头。
It's when the parents pass away that the population goes down to one.
当父母去世时，人口就会减少到一个。
Okay?
好的？
So, that's exactly where the planet is right now.
所以，这正是地球现在所在的位置。
A lot of the grandparents have not passed away, there are not a lot of grandchildren, so it looks like the population is still growing.
很多祖父母还没有去世，孙辈也不多，所以看起来人口仍在增长。
When the grandparents start passing away over the next few years is when the population will peak and then start declining.
当祖父母在未来几年开始去世时，人口将达到顶峰，然后开始下降。
But, the point is, we don't have enough grandchildren already.
但是，关键是，我们还没有足够的孙子。
Russ Roberts: Yeah.
拉斯·罗伯茨：是的。
We're going to talk soon about whether this is good or bad.You listeners out there may have some thoughts about this is great news or scary news, depending on your perspective.
我们很快就会讨论这是好还是坏。你们听众可能会认为这是好消息还是可怕消息，这取决于您的观点。
But what I think is fascinating about it is: it's news.
但我认为它的迷人之处在于：它是新闻。
I didn't know it.
我不知道。
I did not realize this until I saw your post you did on X about this.
直到我看到您在 X 上发表的有关此问题的帖子后，我才意识到这一点。
You point out, for example, that China, which is, I think, the world's second most populous country, records 3.3 million more deaths than births a year.
例如，您指出，我认为中国是世界第二人口大国，每年的死亡人数比出生人数多 330 万人。
Russ Roberts: I did not expect that.
拉斯·罗伯茨：我没想到会这样。
I think you point out we had 138 million births per year in 2012.
我想你指出 2012 年我们每年有 1.38 亿人出生。
Russ Roberts: That was for the world, correct?
拉斯·罗伯茨：那是为了全世界，对吗？
Russ Roberts: Now, that number's down to 124 million, which is why we're at 2.18.
Russ Roberts：现在，这个数字下降到了 1.24 亿，这就是为什么我们的数字是 2.18。
Population will, as you say, because of momentum, continue to rise until, you estimate--it has to be an estimate--2055.
正如你所说，由于势头，人口将继续增长，直到你估计——这必须是一个估计——2055年。
Jesús Fernández-Villaverde: Mm-hmm, exactly.
Jesús Fernández-Villaverde： 嗯嗯，没错。
Momentum historically has lasted around 30 years, and that's why we are going to be peaking in 2055.
从历史上看，这种势头持续了大约 30 年，这就是为什么我们将在 2055 年达到顶峰。
Now, I want to be very honest.
现在，我想非常诚实。
I think it's extremely important for anyone involved in the study of society to be very humble.
我认为对于任何参与社会研究的人来说，保持谦虚是极其重要的。
Things can change.
事情可能会改变。
Okay?
好的？
Tomorrow morning, we all decide to start having kids like crazy, and things can change.
明天早上，我们都决定开始疯狂地生孩子，事情可能会改变。
So, I want to be very, very humble about it.
所以，我想对此保持非常非常谦虚的态度。
But, given what I have observed as of 10:40 AM on September 10th, 2026, this doesn't seem to be stopping, and it's going to completely change the planet.
但是，根据我截至 2026 年 9 月 10 日上午 10:40 的观察，这似乎并没有停止，而且它将彻底改变这个星球。
It's going to completely reshape the geopolitics of the planet.
它将彻底重塑地球的地缘政治。
It's completely going to reshape the political economy of the planet.
它将彻底重塑地球的政治经济。
Regardless of whether you think this is good or bad, I think that most people hugely underestimate the change that this is going to imply in our society.
不管你认为这是好还是坏，我认为大多数人都极大地低估了这将给我们的社会带来的变化。
Russ Roberts: So, I want to say one thing about the humility part.
拉斯·罗伯茨：所以，我想就谦逊部分说一件事。
I made the remark earlier that nature doesn't make jumps; and yet, as we'll see, there have been some remarkable changes, which we're going to highlight, that were not anticipated and that we don't understand, that help us understand how we got to where we are.
我之前说过，大自然不会跳跃；它会跳跃。然而，正如我们将看到的，发生了一些显着的变化，我们将强调这些变化，这些变化是我们没有预料到的，也是我们不理解的，这有助于我们理解我们是如何到达现在的位置的。
Before we get to that--and we'll get to that in a second--I want you to say one thing--well, maybe four things--about the United Nations [UN].
在我们开始之前——我们稍后会谈到——我想让你说一件事——好吧，也许是四件事——关于联合国[UN]。
Because, the United Nations forecasts population, and in passing--in another presentation you made, you mentioned that you are skeptical of those forecasts.
因为，联合国预测人口，顺便说一句，在您所做的另一次演讲中，您提到您对这些预测持怀疑态度。
You know this world, of course, in a way I don't know it.
当然，你以我不知道的方式了解这个世界。
A lot of people rely on those forecasts or find them objective or the best available.
很多人依赖这些预测，或者认为它们是客观的或最好的。
They're crazy .
他们疯了。
They don't make any sense.
它们没有任何意义。
Russ Roberts: That's a fascinating problem in and of itself, but explain why you don't trust them.
拉斯·罗伯茨：这本身就是一个令人着迷的问题，但请解释一下为什么你不信任他们。
Jesús Fernández-Villaverde: Okay.
赫苏斯·费尔南德斯-维拉韦德：好的。
So, first of all, something you can do is the following.
因此，首先，您可以做以下事情。
The United Nations will tell you that so many children were born in country X, and what you can do--they actually tell you how many children were born in country X in 2023 or in 2022, in the past.
联合国会告诉你，X国出生了那么多孩子，你能做什么——他们实际上告诉你，在过去的2023年或2022年，X国出生了多少孩子。
And then you go to the National Institute of Statistics of this country, and the number is very different.
然后你去这个国家的国家统计局，这个数字就相差很大。
And it's always lower.
而且总是更低。
Now, you can say, 'Maybe this is a country that doesn't do a very good job at accounting for data.
现在，你可以说，‘也许这个国家在数据统计方面做得不太好。
Maybe it's a developing economy that is struggling to get with the statistics.' But, we are not talking about those countries.
也许是一个正在努力获取统计数据的发展中经济体。但是，我们不是在谈论这些国家。
We are talking about Denmark.
我们正在谈论丹麦。
Okay?
好的？
Denmark, for good or for bad--the good thing about having a very developed welfare state is that every child, as soon as he's born, it gets his social security number, it goes into a database, everything is recorded.
丹麦，无论好坏——拥有一个非常发达的福利国家的好处是，每个孩子一出生，就会得到他的社会安全号码，进入数据库，一切都会被记录下来。
The most striking example that I have is Colombia, where the United Nations is overestimating births by, like, 60%.
最引人注目的例子是哥伦比亚，联合国高估了哥伦比亚的出生率，大约 60%。
I talk with people at Colombia.
我和哥伦比亚的人交谈。
Colombia has great statisticians and great demographers, and I ask them, 'Are you guys missing 60% of births?' And, they say, 'There's no chance on earth or hell that we are missing 60% of births.'
哥伦比亚拥有出色的统计学家和人口统计学家，我问他们，“你们的出生率是否有 60% 的缺失？”他们还说，“无论是地球还是地狱，我们都不可能错过 60% 的出生。”
Second thing--and I posted something on X this very morning--if you look at the forecast of the United Nations, every two years they are taking 250 million off from the forecast.
第二件事——今天早上我在 X 上发布了一些内容——如果你看看联合国的预测，每两年他们就会从预测中减少 2.5 亿。
So, the way I think this is going on is: I know that my forecast is crazy, I don't want to change my forecast all of a sudden, so what I'm going to do is take advantage that most journalists are lazy, and I'm going to take out 200 million in every two years because no one is going to look at what I have been doing for the last decade.
所以，我认为事情正在发生的方式是：我知道我的预测很疯狂，我不想突然改变我的预测，所以我要做的就是利用大多数记者的懒惰，我将每两年拿出2亿，因为没有人会看我在过去十年里做了什么。
And, before you realize, I have corrected my forecast.
而且，在你意识到之前，我已经纠正了我的预测。
So, by now, they have already taken out one billion people from their forecast.
所以，到目前为止，他们已经从预测中剔除了 10 亿人。
I mean, one billion people from a forecast is a lot of people.
我的意思是，根据预测，十亿人是很多人。
In seven years.
七年之内。
They have taken out one billion people in seven years.
他们在七年内消灭了十亿人。
And remember--and I promised I was not going to use many terms of art--this is a stock variable.
请记住——我保证我不会使用很多专业术语——这是一个股票变量。
It's not a flow.
这不是一个流量。
What I mean by a stock is the total population.
我所说的存量是指总人口。
So, to take out one billion from the total, you need to take out a lot of births.
因此，要从总数中取出 10 亿，就需要取出大量出生人口。
And, the final reason why I don't believe the United Nations is because their forecast of fertility have a built-in reversion to the mean, and this is just a statistical assumption.
而且，我不相信联合国的最后一个原因是因为他们对生育率的预测有内在的均值回归，而这只是一个统计假设。
It may be true, but this is just that you have cooked that up into the forecast.
这可能是真的，但这只是您将其纳入预测而已。
They basically have a statistical method where fertility, by construction, is going to recover.
他们基本上有一个统计方法，通过构建，生育率将会恢复。
Russ Roberts: And, you show a number of examples where the trend is clearly intensely downward, and then, all of a sudden, in the forecast, it reverses.
拉斯·罗伯茨：而且，你举了很多例子，其中趋势明显急剧下降，然后突然在预测中出现逆转。
Which is possible, as you say--who knows?--but unlikely unless you have a reason to believe something is going to change.
正如你所说，这是可能的——谁知道呢？——但不太可能，除非你有理由相信某些事情将会改变。
It's just a built-in statistical assumption that it's going to get back to the average.
这只是一个内置的统计假设，即它将回到平均值。
Which is implausible.
这是难以置信的。
Jesús Fernández-Villaverde: Exactly.
赫苏斯·费尔南德斯-维拉韦德：没错。
And, look, what it bothers me is the follows.
而且，看，让我困扰的是以下内容。
It's not as much that you have an assumption.
这并不是说你有一个假设。
Look, I'm an economist.
听着，我是一名经济学家。
I'm in the business, often, on making forecast.
我从事的工作经常是进行预测。
We are often wrong as a profession.
作为一个职业，我们经常犯错。
I think that the important issue is to be very open about what you're assuming and let the reader decide.
我认为重要的问题是对你的假设持非常开放的态度，并让读者决定。
You say, 'Look, I think that fertility is going to recover because of reason X'; but you put it over there, at the top of the paper, at the top of the report, and then everyone can judge it.
你说，“看，我认为由于 X 原因，生育能力将会恢复”；但你把它放在那边，放在论文的顶部，放在报告的顶部，然后每个人都可以判断它。
The problem is that, to figure it out, what is going on, you need to go to Appendix C11, footnote 17, third paragraph.
问题是，要弄清楚发生了什么，您需要转到附录 C11，脚注 17，第三段。
And that's what I don't like.
这就是我不喜欢的。
I don't like the fact that you're trying to hide for me from what you are doing.
我不喜欢你试图向我隐瞒你正在做的事情。
I'm very happy--I'm an editor of a journal, of a major journal of economics--and sometimes I get crazy papers, and sometimes I accept them.
我很高兴——我是一本期刊的编辑，一本主要经济学期刊的编辑——有时我会收到疯狂的论文，有时我会接受它们。
But, the crazy papers that I accept say in the first line, 'I'm going to do something crazy, but that I think is interesting,' and that's fine with me.
但是，我接受的疯狂论文在第一行就说，“我要做一些疯狂的事情，但我认为很有趣”，这对我来说很好。
The papers that I always reject are the papers that do something crazy, but the assumption is hidden in footnote 27.
我总是拒绝的论文是那些做了疯狂的事情的论文，但假设隐藏在脚注 27 中。
That, I don't like.
那个，我不喜欢。
Russ Roberts: No. So, one thing we should just add as a stylized fact, as an expression economists like to use to mean mostly pretty much true, close, not exact--stylized, meaning it's close: you mentioned that you might naively believe that you need a replacement rate of 2.1 children per woman to get to a stable population.
拉斯·罗伯茨：不。所以，我们应该添加一件事作为一个程式化的事实，经济学家喜欢用这个表达来表示几乎真实的、接近的，而不是精确的——程式化，意味着它是接近的：你提到你可能天真地认为你需要每名妇女生育 2.1 个孩子的替代率才能达到稳定的人口。
It's probably closer to 2.2.
可能更接近2.2。
And, as you point out, we just recently passed a point where it's 2.18 worldwide.
而且，正如您所指出的，我们最近刚刚度过了全球 2.18 的关键时刻。
And so, for the first time in modern history, for sure, population is going to fall in the future if nothing else changes.
因此，如果没有其他变化，未来人口肯定会下降，这在现代历史上是第一次。
We are having a smaller number of children per woman that would allow it to stay stable.
我们每名女性生育的孩子数量较少，这将使其保持稳定。
But, you should know, listeners, if you haven't looked at this data, and I've looked at it a little bit, and Jesús has looked at it immensely more: Most countries in the West are well below 2.
但是，听众们，如果你们还没有看过这些数据，你们应该知道，我看过一点，耶稣看过的也多得多：大多数西方国家的数字都远低于2。
Other than Israel, which you mention in passing, I don't think there's a so-called developed country that is close to 2--forget 2.1--and many of them are under one and a half.
除了你顺便提到的以色列之外，我认为没有一个所谓的发达国家接近2——忘了2.1——而且很多都低于1.5。
Am I right?
我说得对吗？
Jesús Fernández-Villaverde: Yes, and many are below 1.
Jesús Fernández-Villaverde：是的，很多都低于 1。
Russ Roberts: Gary Becker, along with Robert Barro, as you point out, had this idea that as nations get richer, instead of having more children--the quantity of children--they have higher quality of children.
拉斯·罗伯茨：正如您所指出的，加里·贝克尔和罗伯特·巴罗都有这样的想法，即随着国家变得更加富裕，他们的孩子不是更多的孩子——孩子的数量——而是更高的质量。
They invest more in their children, more in their children's education, maybe their musical loves.
他们对孩子投入更多，对孩子的教育，也许还有对音乐的热爱投入更多。
They get more lessons, they get more training of all kinds.
他们接受更多的课程，接受更多的各种培训。
And so, that's what happens as countries get richer.
因此，这就是随着国家变得更加富裕而发生的情况。
They have fewer children, but so-called higher quality.
他们的孩子较少，但所谓质量较高。
This is a word that creeps out, a non-economist.
这是一个不经意间出现的词，“非经济学家”。
But, as economists, we just say, what we mean by that is they invest more.
但是，作为经济学家，我们只是说，我们的意思是他们投资更多。
And, to make a really creepy example, it's like saying: when people get richer, they don't buy more cars.
而且，举一个非常令人毛骨悚然的例子，这就像在说：当人们变得更富有时，他们不会购买更多的汽车。
They buy a better car, a more expensive car, a car with more features.
他们购买更好的汽车、更昂贵的汽车、具有更多功能的汽车。
So, children and cars are not the same.
所以，孩子和汽车不一样。
It's an offensive analogy.
这是一个令人反感的类比。
But, economists--that's roughly the way economists look at it.
但是，经济学家——这就是经济学家看待它的大致方式。
Something, which I was unaware of--this is one of the shocking things--has changed.
我没有意识到的一些事情——这是令人震惊的事情之一——已经改变了。
Explain the relationship between income and children--population growth, fertility--as across countries, and then within a country, rich families versus poorer families, or richer, higher-income women versus lower-income women.
解释收入与儿童（人口增长、生育率）之间的关系，以及在不同国家之间的关系，以及在一个国家内部，富裕家庭与贫困家庭的关系，或者较富裕、高收入的女性与低收入女性的关系。
And, when I repeated what you're about to say to friends of mine, I literally saw a physical reaction, like, 'Well, obviously, that's not true.
而且，当我向我的朋友们重复你要说的话时，我确实看到了一种身体反应，比如，‘好吧，显然，这不是真的。
Obviously, that's wrong.' So, tell us.
显然，这是错误的。那么，请告诉我们。
Jesús Fernández-Villaverde: Okay.
赫苏斯·费尔南德斯-维拉韦德：好的。
So, what has happened--you're absolutely right--the Barro-Becker model.
那么，发生了什么——你是绝对正确的——巴罗-贝克尔模型。
I was educated on the Barro-Becker model.
我接受了巴罗-贝克尔模型的教育。
Chapter 1 of my Ph.D. dissertation is the Barro-Becker model with some twist.
我的博士学位的第一章论文是带有一些扭曲的巴罗-贝克尔模型。
Okay?
好的？
So, for 30 years, I have been a proud card-carrying member of the Barro-Becker Union.
因此，30 年来，我一直是巴罗-贝克尔联盟的一名光荣会员。
Now, in fact, what has happened is that fertility in rich countries has gone down, as Barro-Becker will have forecast, so good for Barro-Becker.
现在，事实上，正如巴罗-贝克尔所预测的那样，富裕国家的生育率已经下降，这对巴罗-贝克尔来说是件好事。
But, what is amazing is that middle-income countries, it has dropped even more , which has meant that the slope has changed from being negative--the richer you are, the fewer children you have--into being positive.
但是，令人惊奇的是，中等收入国家的下降幅度更大，这意味着斜率从负值（越富有，孩子越少）变为正值。
Now, we want to be very careful because, for this to be true at the world level, you still need to take Sub-Saharan Africa out.
现在，我们要非常小心，因为要在世界范围内实现这一点，您仍然需要将撒哈拉以南非洲地区排除在外。
I'm going to come back to Sub-Saharan Africa, if you want, later.
如果你愿意的话，我稍后会回到撒哈拉以南非洲。
Okay?
好的？
But basically, if you say, 'Let's look at middle-income countries and rich countries,' that's already the case: that richer countries have higher fertility than poorer countries.
但基本上，如果你说，“让我们看看中等收入国家和富裕国家”，情况已经如此：富裕国家的生育率高于贫穷国家。
Russ Roberts: So, their fertility rate has fallen, but it's fallen more in the middle-level countries?
拉斯·罗伯茨：那么，他们的生育率下降了，但中等国家下降得更多？
Jesús Fernández-Villaverde: And, that's what Barro-Becker cannot account for.
Jesús Fernández-Villaverde：而且，这是 Barro-Becker 无法解释的。
Russ Roberts: And, give us a couple examples of what would be a so-called middle-level country versus a rich country.
拉斯·罗伯茨：请给我们举几个例子来说明什么是所谓的中等国家与富裕国家。
Jesús Fernández-Villaverde: Okay.
赫苏斯·费尔南德斯-维拉韦德：好的。
Mexico: fertility rate, 1.51.
墨西哥：生育率，1.51。
The United States: fertility rate, 1.57.
美国：生育率，1.57。
Now, I know that many of your listeners are going to have the following thought: 'Oh, fertility rate in the United States is high because we have a lot of people with funny accents like you, Jesús, that have a lot of kids.' No. Let's look at the fertility of non-Hispanic white women.
现在，我知道你们的许多听众都会有以下想法：“哦，美国的生育率很高，因为我们有很多像你一样口音奇怪的人，天哪，他们有很多孩子。”不。让我们看看非西班牙裔白人女性的生育能力。
It's 1.55.
是1.55。
It's higher than Mexico's fertility.
它比墨西哥的生育率还要高。
So, the test I always give my undergrads, if you are at Penn--this is supposed to be a good university--'Go out and ask how many faculty knows that the fertility rate of non-Hispanic white women in the United States is higher than the fertility of Mexico.'
因此，我总是给我的本科生做这样的测试，如果你在宾夕法尼亚大学——这应该是一所好大学——“出去问问有多少教师知道美国非西班牙裔白人女性的生育率高于墨西哥。”
Let me give you another example.
让我再举一个例子。
I'm going to give you two countries, Russ.
我要给你两个国家，拉斯。
You need to tell me which one do you think has a higher fertility: Japan or Colombia?
你需要告诉我你认为哪个国家的生育率更高：日本还是哥伦比亚？
Russ Roberts: Now, Japan is a famous example of a country that has been struggling with its population.
拉斯·罗伯茨：现在，日本是一个一直在与人口斗争的国家的著名例子。
There's been a lot of things written about Japan's economy and political promises being hard to meet because women in Japan are having fewer children than they did before.
有很多关于日本经济和政治承诺难以兑现的文章，因为日本女性生育的孩子比以前少了。
So, obviously, I would say Japan has a lower fertility rate.
所以，显然，我会说日本的生育率较低。
Jesús Fernández-Villaverde: Yeah, but of course, this was a leading question.
Jesús Fernández-Villaverde：是的，但当然，这是一个引导性问题。
Russ Roberts: I know.
拉斯·罗伯茨：我知道。
I'm not trying to get a good grade.
我并不是想取得好成绩。
Jesús Fernández-Villaverde: I know.
赫苏斯·费尔南德斯-维拉韦德：我知道。
You're being a good sport.
你是一个很好的运动者。
You're being a good sport.
你是一个很好的运动者。
Russ Roberts: Exactly.
拉斯·罗伯茨：没错。
I'm not trying to get a good grade.
我并不是想取得好成绩。
I'm just trying to help the conversation.
我只是想帮助谈话。
Jesús Fernández-Villaverde: Colombia has lower fertility, and that's what is surprising.
Jesús Fernández-Villaverde：哥伦比亚的生育率较低，这令人惊讶。
The surprising thing is not that fertility went down in Japan.
令人惊讶的并不是日本的生育率下降。
Barro and Becker will say, 'We brought a model for that.' The amazing thing is that fertility has collapsed in Thailand, in Sri Lanka, in Chile, in Colombia.
巴罗和贝克尔会说，“我们为此带来了一个模型。”令人惊奇的是，泰国、斯里兰卡、智利、哥伦比亚的生育率大幅下降。
Let me give you another example: Guatemala.
让我再举一个例子：危地马拉。
Okay, Guatemala, a lovely country, I have Guatemalan friends; but it's one of the most less developed economies in Central America.
好吧，危地马拉，一个可爱的国家，我有危地马拉的朋友；但它是中美洲最欠发达的经济体之一。
Guatemala's total fertility rate was, in 2007, around 3.7, which is the level of Sub-Saharan Africa.
2007年，危地马拉的总生育率约为3.7，与撒哈拉以南非洲地区的水平相当。
Last year, it was probably around 1.8.
去年，这个数字可能在1.8左右。
At the current rate, Guatemala will have lower fertility rate than the United States before the year 2030.
按照目前的速度，到2030年，危地马拉的生育率将低于美国。
Let me put it in this way.
让我这样说吧。
If Jesús has a time travel machine and goes back to 2005 and finds my younger self as an assistant professor at Penn and tells him, 'Guatemala will have lower fertility rate than the United States by the year 2030,' I will have to say, 'I'm willing to take a $1 to $1 million bet that that's not going to be the case.' And I will have been broke.
如果 Jesús 有一台时间旅行机器，回到 2005 年，找到年轻时的我，在宾夕法尼亚大学担任助理教授，并告诉他，“到 2030 年，危地马拉的生育率将低于美国”，我将不得不说，“我愿意打 1 到 100 万美元的赌注，但情况不会如此。”我就会破产了。
And that's the amazing thing.
这就是令人惊奇的事情。
Now, let me come back to the within-country.
现在，让我回到国内。
So, again, it used to be the case that poorer people--now let's think about the United States--poorer people in the United States will have more children; richer people in the United States will have fewer children.
所以，再说一次，过去的情况是，越穷的人——现在让我们想想美国——美国越穷的人就会有更多的孩子；现在我们想想美国。美国越富有的人生育的孩子就越少。
That has flipped, and that has flipped.
事情已经翻转了，事情已经翻转了。
If I can make the joke for a second, the joke I always make in my talks to the big public is that the ultimate status symbol for a finance bureau is Arabian and three kids.
如果我可以开个玩笑的话，我在向公众演讲时总是开的玩笑是，财政局的最终地位象征是阿拉伯人和三个孩子。
And it's very easy to tell.
这很容易分辨。
You talk with a lot of people in the financial sector, you talk with a lot of people in high-income professions, and three kids is not unusual.
你与很多金融领域的人交谈，你与很多高收入职业的人交谈，三个孩子并不罕见。
And, at the same time, you go to the lower levels of the income distribution, and you have one.
与此同时，你进入了收入分配的较低层次，你就拥有了一个。
Let me give you another observation.
让我给你另一个观察。
Since the creation of the United States until around early 2024, the fertility rate of African Americans was higher than the fertility rate of non-Hispanic whites.
自美国建国以来直至2024年初左右，非裔美国人的生育率高于非西班牙裔白人的生育率。
And, that's the reason why the African American population stayed roughly constant as a percentage of the United States population, despite the fact that there were huge influx of immigration from other groups in the 19th century, from whites from Europe, later in the 20th century, from people from Latin America, and more recently, from Asia.
这就是为什么非裔美国人人口在美国人口中所占的比例大致保持不变的原因，尽管 19 世纪有来自其他群体、来自欧洲的白人、20 世纪后期、来自拉丁美洲以及最近来自亚洲的大量移民涌入。
Since 2024, the fertility of non-Hispanic whites is higher than the fertility of African Americans, and the fertility of African Americans is collapsing at an enormous speed.
自2024年以来，非拉美裔白人的生育率高于非裔美国人的生育率，而非裔美国人的生育率正在以惊人的速度崩溃。
Now, unfortunately, it's still the case that, in the United States, African Americans tend to be associated with lower income.
不幸的是，现在的情况仍然是，在美国，非洲裔美国人往往与较低的收入联系在一起。
That's a very easy way to tell it in the data.
这是通过数据来表达的一种非常简单的方法。
The collapse in fertility right now is being concentrated among the low educated, the low income, or the middle educated and the middle income, both within countries and across countries.
目前生育率的下降主要集中在国家内部和国家之间的低教育、低收入或中等教育和中等收入人群。
And, that's really what the Barro-Becker model struggles a lot to understand.
而且，这确实是巴罗-贝克尔模型很难理解的地方。
Russ Roberts: But, forget the model.
拉斯·罗伯茨：但是，忘记模型吧。
What we're looking at is a reversal of an empirical regularity, which is why I use the 'stylized fact' word/phrase.
我们所看到的是经验规律的逆转，这就是我使用“程式化事实”一词/短语的原因。
There was a very--forget the utility functions and the math of Barro and Becker.
有一个非常——忘记巴罗和贝克尔的效用函数和数学。
The bottom line for a long, long time was that once you got rich, your families got smaller and its population growth would slow down, and that is true--excuse me--that that finding no longer is statistically--is not a fact--is shocking.
很长一段时间以来的底线是，一旦你变得富有，你的家庭就会变得更小，人口增长也会放缓，这是事实——对不起——这一发现不再是统计数据——不是事实——令人震惊。
Before we go on to the causes of this, which are frustratingly elusive, give us a feel for some of the--in Western Europe, what are some of the current levels of fertility?
在我们继续探讨这一令人沮丧的难以捉摸的原因之前，让我们先了解一下西欧目前的生育水平是多少？
Because they're shockingly low.
因为它们的含量低得惊人。
Jesús Fernández-Villaverde: Yeah.
赫苏斯·费尔南德斯-维拉韦德：是的。
So, I can tell you from the top of my head, and I apologize if I get the second decimal wrong: in Spain, it's around 1.2; in Italy, it's around 1.2; in the United Kingdom, it's around 1.4; in France, it's a little bit higher, around 1.7, 1.6; most Scandinavian countries, between 1.5, 1.7; Germany, around 1.3.
所以，我可以从头到尾地告诉你，如果我弄错了小数点后第二位，我深表歉意：在西班牙，这个数字大约是 1.2；在西班牙，这个数字大约是 1.2。在意大利，约为1.2；在英国，约为1.4；在法国，这个数字要高一些，大约是1.7、1.6；大多数斯堪的纳维亚国家，在 1.5 至 1.7 之间；德国，1.3左右。
So, yeah, basically, you don't have any one above 1.8, so not even close.
所以，是的，基本上，你没有任何高于 1.8 的版本，所以甚至还差得远。
Russ Roberts: So they're going to get smaller in terms of the number of people who live there unless something remarkably different happens.
拉斯·罗伯茨：所以，除非发生明显不同的事情，否则居住在那里的人数将会减少。
So now, we come to the question of what has happened.
现在，我们来谈谈发生了什么的问题。
Why is this--and by the way, the other part about this that was also so surprising: The trend got dramatically steeper and stronger 10 years ago.
这是为什么——顺便说一句，这件事的另一部分也令人惊讶：十年前，这一趋势变得更加陡峭和强劲。
The last 10 years has seen a steroidal acceleration of this phenomenon.
过去十年来，这种现象急剧加速。
Jesús Fernández-Villaverde: Yes.
赫苏斯·费尔南德斯-维拉韦德：是的。
In the paper with Patrick, we write three words that we should write more often: 'We don't know.' Conditional on that, let me tell you my best reading of the evidence.
在帕特里克的论文中，我们写了三个我们应该经常写的词：“我们不知道。”在此基础上，让我告诉你我对证据的最佳解读。
The way in which we have organized modern society makes extremely difficult to have families with more than two children.
现代社会的组织方式使得拥有两个以上孩子的家庭变得极其困难。
It's really very difficult to have three children.
养三个孩子真的很不容易。
It really conflicts with your work, with your professional career.
这确实与你的工作、你的职业生涯相冲突。
Housing is very expensive, and with three children, you need a bigger house.
住房很贵，而且带着三个孩子，你需要一个更大的房子。
So, most families are opting for two.
所以，大多数家庭都会选择两个。
Now, you're saying, 'Well, they have--'
现在，你说，‘好吧，他们有——’
Russ Roberts: Have children.
拉斯·罗伯茨：生孩子。
Most families that have children tend to--
大多数有孩子的家庭倾向于——
Jesús Fernández-Villaverde: That's exactly where I'm going.
Jesús Fernández-Villaverde：这正是我要去的地方。
That's exactly where I'm going.
这正是我要去的地方。
And what we try to argue in the paper is, if, as a society, your default is two, you are going to end up with 1.4.
我们在论文中试图论证的是，如果作为一个社会，你的默认值是 2，那么你最终会得到 1.4。
Why?
为什么？
Because you are going to have a percentage of women that, for whatever the reason, don't have children, maybe biological or maybe by choice.
因为无论出于何种原因，都会有一定比例的女性没有孩子，可能是亲生的，也可能是选择的。
And, you're going to have also a non-trivial percentage of women that are going to stay at one.
而且，也会有相当一部分女性会留在其中。
And, you are going to have next to nobody with three or more.
而且，几乎没有人拥有三个或更多。
So, if, as a society, your default is 2, you end up with 1.4.
因此，如果作为一个社会，您的默认值是 2，那么您最终会得到 1.4。
And, that's something that I really think most people have not internalized.
而且，我真的认为大多数人还没有内化这一点。
So, when we are talking about countries like the United Kingdom at 1.4, you will go to a park, and you will see children playing.
所以，当我们在1.4谈论像英国这样的国家时，你会去公园，你会看到孩子们在玩耍。
Most children will be playing with a sibling.
大多数孩子会和兄弟姐妹一起玩耍。
It's not like the one child in China.
这不像中国的独生子女。
And yet, with two children, as soon as you take account of the few women that will be at zero and the non-trivial amount of women at one, you get stuck in 1.4.
然而，如果你有两个孩子，一旦你考虑到少数女性的得分为零，而女性的得分为一的人数也不少，你就会陷入 1.4 的困境。
So, if you want to get to 2 replacement rate, you need a lot of families with three; and that's what we are not seeing anymore.
所以，如果你想达到2的替代率，你需要很多有3个家庭的家庭；这就是我们不再看到的情况。
And, what we try to argue in the paper is that we have organized society in a way where getting to three is extremely difficult, and those societal changes have spread through the planet like wildfire over the last 20, 30 years; and the last 10 years is just kind of the exponential part of that phenomenon where, in some sense, things that we have been building for decades are coming to fruition.
而且，我们在论文中试图论证的是，我们组织社会的方式使得达到三级是极其困难的，而这些社会变革在过去 20、30 年里像野火一样在地球上蔓延；过去十年只是这种现象的指数级部分，从某种意义上说，我们几十年来一直在建设的东西正在取得成果。
Russ Roberts: Well, fortunately, I'm an economist because, if I weren't, I might be tempted to say, 'Well, you're obviously wrong because we have four kids.' But, we are the exception.
拉斯·罗伯茨：嗯，幸运的是，我是一名经济学家，因为如果我不是，我可能会想说，“嗯，你显然错了，因为我们有四个孩子。”但是，我们是例外。
Russ Roberts: Obviously, we're very aware that that's an unusually large family when we lived in the United States.
拉斯·罗伯茨：显然，当我们住在美国时，我们非常清楚这是一个异常大的家庭。
Here, in Israel, it's not large at all.
在以色列这里，它一点也不大。
As we mentioned earlier, Israel is well above replacement--not just among the religious population, where people assume they have large family, which they do on average, but even among secular Israelis.
正如我们之前提到的，以色列远远高于更替——不仅在宗教人口中，人们认为他们有一个大家庭（他们平均如此），甚至在世俗的以色列人中也是如此。
Russ Roberts: But, I'm an economist, so I know that four is rare.
拉斯·罗伯茨：但是，我是一名经济学家，所以我知道四个是罕见的。
Why would it be the case?
为什么会这样呢？
Obviously, in 1950, when TFR, total fertility rate, was 5 for the world--what might it have been in the United States in 1950?
显然，在 1950 年，全世界的 TFR（总生育率）为 5——1950 年的美国会是多少呢？
Jesús Fernández-Villaverde: Around 2.5, 2.6.
赫苏斯·费尔南德斯-维拉韦德：大约2.5、2.6。
Russ Roberts: Okay, so above replacement rate--their poor population, growing steadily, as we know, many more people in the United States today than there were in 1950.
拉斯·罗伯茨：好的，所以高于更替率——正如我们所知，他们的贫困人口正在稳步增长，今天美国的人口比 1950 年要多得多。
Something changed.
有些事情发生了变化。
We don't know what that is.
我们不知道那是什么。
You point to that in the paper, by the way, and it's a very readable paper--for the things you won't understand if you're not an economist, you can skip those parts.
顺便说一句，你在论文中指出了这一点，这是一篇非常易读的论文——如果你不是经济学家，你不会理解的事情，你可以跳过这些部分。
You talk about some of the other theories that were less religious as a nation, America is, and the West is generally--the smartphone has changed social life, there's social media, and so on and so on.
你谈到了其他一些理论，这些理论作为一个国家来说宗教信仰较少，美国是，西方一般都是——智能手机改变了社会生活，有社交媒体，等等。
We'll talk about some of--whether that could contribute or not or how decisive it is.
我们将讨论其中的一些内容——无论是否有贡献，或者它的决定性如何。
But, your claim--I'm going to read a quote from the paper, which is a bold claim, it's a provocative claim--you say the following:
但是，你的主张——我要读一下这篇论文的引文，这是一个大胆的主张，这是一个挑衅性的主张——你说如下：
What was different in 1950?
1950 年有什么不同？
Why were three children expensive in the United States--excuse me--cheap in 1950 that so many people had three children?
为什么在 1950 年美国养三个孩子这么贵——对不起——这么便宜，那么多人养三个孩子？
Jesús Fernández-Villaverde: So, a couple of thoughts.
Jesús Fernández-Villaverde：那么，有几点想法。
First, the degree to which these mechanisms that I'm emphasizing--like, for instance, the requirement for formal credentials--was much more limited.
首先，我所强调的这些机制（例如，对正式证书的要求）的程度要有限得多。
So, think about 1950.
那么，想想 1950 年。
I'm a middle-class person in a small town in Minnesota.
我是明尼苏达州一个小镇上的中产阶级。
My three kids can graduate from high school, get a job in a local factory, and make a very serious middle-class income.
我的三个孩子可以从高中毕业，在当地一家工厂找到一份工作，并获得非常可观的中产阶级收入。
So, I basically think about my kids.
所以，我基本上想到的是我的孩子。
I send them to public school, they graduate.
我送他们去公立学校，他们毕业了。
By the time they are 18, I get rid of them.
当他们18岁的时候，我就摆脱了他们。
Well, that's not really what you can do with your kids any longer if you want them to have a middle class life.
好吧，如果你想让你的孩子过上中产阶级生活，你就不能再对他们做这样的事情了。
You need to send them to college.
你需要送他们上大学。
You may even need to pay for some type of professional or postgraduate education.
您甚至可能需要支付某种类型的专业或研究生教育的费用。
Before you realize, you are really on top of your children for 25, 27 years.
在你意识到之前，你已经掌控了你的孩子 25、27 年。
And it's not only that you need to care much more about your children, it's that your own life starts later.
不仅你需要更多地关心你的孩子，而且你自己的生活也需要更晚才开始。
Think about an economist.
想想一位经济学家。
You go to college when you're 18, you graduate when you are 22.
18岁上大学，22岁毕业。
These days, we have this awful thing called pre-docs, which should be prohibited, but that's a different conversation.
如今，我们有一种可怕的东西叫做预文档，它应该被禁止，但这是一个不同的话题。
So, by the time you start your Ph.D., you are 24.
所以，当你开始攻读博士学位时，你已经 24 岁了。
Then the Ph.D., by now, is six years.
那么博士学位到现在已经六年了。
So, by the time you finish, you are 30.
所以，当你完成时，你已经30岁了。
You get your first job as an assistant professor, maybe directly when you're 30, maybe after one year of postdoc, you are 31; and that's the moment where you start thinking about building a family.
你得到第一份工作是助理教授，也许在你30岁的时候直接找到，也许在博士后一年后，你就31岁了；那就是你开始考虑建立家庭的那一刻。
You're already 31.
你已经31岁了。
The biological clock has already ticked more than half your fertile age.
生物钟已经过去了你生育年龄的一半以上。
So, no matter how hard you try, no matter how hard you try to organize your life, going for three is going to be very difficult, and who, say, is an assistant professor in economics, say someone who went to law school, say someone who did an MBA [Master of Business Administrations], etc.
所以，无论你如何努力，无论你如何努力安排自己的生活，追求三个都会非常困难，比如说，一个经济学助理教授，一个读过法学院的人，一个读过MBA（工商管理硕士）的人等等。
So, you're basically saying, 'Hey, on one hand, it takes me a lot of time to get to the job market.
所以，你基本上是在说，‘嘿，一方面，我需要很多时间才能进入就业市场。
It takes me a lot of time to settle down as a middle-income family or an upper-middle-income family.
我花了很多时间才能安定下来成为中等收入家庭或中上收入家庭。
And in addition to it, this is the same thing that will happen with my kids, and I need to provision for that, and I need to take account of that.' Suddenly, having the third kid becomes extremely expensive.
除此之外，我的孩子也会发生同样的事情，我需要为此做好准备，我需要考虑到这一点。”突然间，生第三个孩子变得极其昂贵。
On the other hand, if I don't have kids, I have a welfare state.
另一方面，如果我没有孩子，我就有福利国家。
Now, in the United States, it's a little bit less generous than in other countries.
现在，在美国，它比其他国家稍微不那么慷慨。
But, if I'm in Europe, I don't really need kids to sustain me for my old age.
但是，如果我在欧洲，我真的不需要孩子来养活我的晚年。
I'm going to have access to some type of public health.
我将获得某种类型的公共卫生服务。
Being a childless person is not a big deal.
作为一个没有孩子的人，没什么大不了的。
Something that I don't emphasize in the paper, because we run out of space: this also has a multiplicative effect.
我在论文中没有强调这一点，因为我们的空间不够了：这也有乘法效应。
The way I like to put it is: you like to be with your friends, and you can be with your friends drinking a beer at the pub on Saturday night, or you can be with your friends at soccer practice with your kids on Saturday morning.
我喜欢的说法是：你喜欢和你的朋友在一起，你可以在周六晚上和你的朋友一起在酒吧喝啤酒，或者你可以在周六早上和你的朋友和你的孩子一起参加足球训练。
If it happens to be the case that a non-trivial amount of your friends are childless, you can go with them to the pub on Saturday night.
如果你碰巧有不少朋友没有孩子，你可以在周六晚上和他们一起去酒吧。
So, you can have these peer group effects that multiply relatively small changes very, very fast.
因此，这些同侪群体效应可以非常非常快地增加相对较小的变化。
So, that's basically what we are trying to say is, real life, modern life makes really very difficult.
所以，这基本上就是我们想说的是，现实生活，现代生活确实变得非常困难。
I mean, I'm thinking about my own graduate students.
我的意思是，我正在考虑我自己的研究生。
If they want to have children, it's really a very difficult situation for them, even if they want to have children.
如果他们想要孩子，那对他们来说确实是一个非常困难的处境，即使他们想要孩子。
If you want to go through tenure track, it's going to be very difficult to have three children or more.
如果你想获得终身教职，拥有三个或更多的孩子将会非常困难。
And, on the other hand, the temptations of not having kids are very high because life is not very inconvenient if you don't have kids anymore.
另一方面，不生孩子的诱惑也很大，因为如果你不再生孩子，生活也不会很不方便。
And again, I'm not saying that this is pushing everyone to go to zero.
再说一遍，我并不是说这会迫使每个人归零。
My argument is that this is basically pushing a lot of people that used to have three to two, and some people that used to have two to one.
我的观点是，这基本上推动了很多过去三比二的人，以及一些过去二比一的人。
So, it's not like a dramatic decision.
所以，这并不是一个戏剧性的决定。
It's not like you meet with your wife and say, 'Honey, we are not going to have kids.' It's that when people are thinking, 'Should I have a third kid or not?' they say, 'Well, a third kid is a little bit tricky.' And, that's what gets us there.
这不像你和你的妻子见面时说：“亲爱的，我们不会要孩子了。”当人们在思考“我是否应该生第三个孩子？”的时候。他们说，“好吧，第三个孩子有点棘手。”这就是我们到达那里的原因。
So it's not this idea of an economist solving, in the living room, a dynamic programming problem.
所以这不是经济学家在客厅里解决动态规划问题的想法。
That's not what I have in mind.
我的想法不是这个。
What I have in mind is you are having a nice dinner with your wife or your spouse, and you say, 'Honey, should we have a third kid?' And then, your spouse enumerates the 17 reasons why having a third kid now is a little bit tricky.
我的想法是，当你和你的妻子或配偶一起吃一顿丰盛的晚餐时，你会说：“亲爱的，我们应该生第三个孩子吗？”然后，你的配偶列举了为什么现在生第三个孩子有点棘手的 17 个原因。
And then, you decide not to have the third kid.
然后，你决定不生第三个孩子。
Russ Roberts: Or you struggle.
拉斯·罗伯茨：或者你会挣扎。
You need more time because you're not fertile immediately and not effective immediately, and so on.
您需要更多时间，因为您不会立即受孕，也不会立即见效，等等。
But, your story--for better or for worse, there aren't that many Ph.D. economists.
但是，你的故事——无论好坏，没有那么多博士学位。经济学家。
One could argue whether that's a good thing for the world or not.
人们可能会争论这对世界来说是否是一件好事。
But, think about a woman who is a cashier at Walmart.
但是，想想一位在沃尔玛担任收银员的女士。
She does not have a Ph.D. She doesn't imagine, necessarily, that her children are going to need a Ph.D. or a law degree or an MBA, but she's having fewer children than that graduate student is going to have, is what you're arguing.
她没有博士学位。她并不认为她的孩子们一定需要博士学位。或者法律学位或工商管理硕士学位，但她的孩子比那个研究生的孩子少，这就是你所说的。
Jesús Fernández-Villaverde: Yeah, exactly.
Jesús Fernández-Villaverde： 是的，完全正确。
Russ Roberts: So, what's going on there?
拉斯·罗伯茨：那么，那里发生了什么？
Jesús Fernández-Villaverde: Okay.
赫苏斯·费尔南德斯-维拉韦德：好的。
So, what I think is going on there is that deep change in gender relations and in gender norms in society.
所以，我认为正在发生的是性别关系和社会性别规范的深刻变化。
So, if you were a cashier and you were 25 years old in 1950, there were a lot of things that were closed to you in society as a single woman.
所以，如果你在 1950 年是一名收银员，25 岁，作为一个单身女性，社会上有很多事情对你来说是封闭的。
That's not the case anymore.
现在情况已不再是这样了。
Jesús Fernández-Villaverde: Yes, closed to you.
Jesús Fernández-Villaverde： 是的，对您关闭。
That's not the case anymore.
现在情况已不再是这样了。
Being a single woman in the early 1950s in Middletown, America, was not particularly pleasant.
20 世纪 50 年代初，在美国米德尔敦，作为一名单身女性并不是特别愉快。
Russ Roberts: Which is why most 25-year-old women in middle America in 1950 were married.
Russ Roberts：这就是 1950 年美国中部大多数 25 岁女性结婚的原因。
The age of marriage was early 20s.
结婚年龄是20岁出头。
Jesús Fernández-Villaverde: Yes, and you may end up marrying someone that you don't particularly like and who is not a particularly good husband for you.
Jesús Fernández-Villaverde：是的，你最终可能会嫁给一个你不特别喜欢的人，而且他对你来说不是一个特别好的丈夫。
So now, it's okay to be single woman when you are 25.
所以现在，25岁单身女性是可以的。
When we were talking about whether or not some of these things are good or bad, I actually put this on the good side of the balance sheet.
当我们谈论其中一些事情是好是坏时，我实际上把它放在资产负债表的好的一边。
Jesús Fernández-Villaverde: And, it basically means--this, I think, is particularly true in a lot of these middle-income countries where the gender norms have changed drastically over the last 25 years.
Jesús Fernández-Villaverde：我认为，这基本上意味着，在许多中等收入国家尤其如此，这些国家的性别规范在过去 25 年里发生了巨大变化。
It was extremely difficult to be a single woman in Mexico in 1990.
1990 年的墨西哥，单身女性的生活极其艰难。
It's not that difficult anymore.
这不再那么困难了。
I mean, it's still difficult that you still suffer some problems, but it's a completely different ballgame.
我的意思是，仍然遇到一些问题仍然很困难，但这是完全不同的游戏。
Jesús Fernández-Villaverde: Let me give you a very simple example.
Jesús Fernández-Villaverde：让我举一个非常简单的例子。
I remember I went to give a seminar at Harvard maybe a couple of years ago.
我记得大概几年前我去哈佛举办了一个研讨会。
When you take that very early flight the next day, so I was waiting at 4:00 AM for the Uber, and I saw a girl walking her dog.
当你第二天乘坐很早的航班时，所以我在凌晨 4:00 等 Uber，我看到一个女孩在遛狗。
She may be in her early 20s.
她可能才20岁出头。
We live in a society where a single woman can walk, in Cambridge, Massachusetts, her dog at 4:00 AM with the reasonable expectation that nothing is going to happen to you.
我们生活在这样一个社会：在马萨诸塞州剑桥，单身女性可以在凌晨 4:00 带着她的狗散步，并合理地预期不会发生任何事情。
Unfortunately, that was not the case in most of the planet 25 years ago, 30 years ago.
不幸的是，25 年前、30 年前，地球上大部分地区的情况并非如此。
So, this woman may feel that the only alternative she has in her life is to marry someone, even if that marriage is not her first choice.
因此，这个女人可能会觉得她一生中唯一的选择就是嫁给某人，即使婚姻不是她的第一选择。
But marriage in that situation probably implies that she's going to have one or two children or maybe three.
但在这种情况下的婚姻可能意味着她将有一个或两个孩子，甚至三个孩子。
That woman now is deciding, 'No, this is not for me.
那个女人现在正在决定，‘不，这不适合我。
I'm perfectly fine.
我很好。
I'm a strong believer in freedom and the dignity of people.' And, if that girl who was walking her dog at Cambridge at 4:00 AM doesn't feel she wants to get married, good for her; and that's what I think it has changed a lot.
我坚信自由和人的尊严。而且，如果那个凌晨 4:00 在剑桥遛狗的女孩不想结婚，那对她来说是件好事；我认为这就是它发生了很大变化的地方。
Now, there is also a related issue that we can talk that I think that, at this moment, we have less marriage that we should have as a society because of some policy decisions we have made, and we can talk about those.
现在，还有一个相关的问题我们可以讨论，我认为，目前，由于我们做出的一些政策决定，我们作为一个社会应该拥有的婚姻减少了，我们可以谈论这些。
But, I think that the first order is that, because the change in gender norms, marriage is not any longer the default for a woman, and we should be happy that that's the case.
但是，我认为首要的是，由于性别规范的变化，婚姻不再是女性的默认选择，我们应该对此感到高兴。
Russ Roberts: I want you to put a footnote in for Sub-Saharan Africa because I don't want to leave that.
拉斯·罗伯茨：我希望你为撒哈拉以南非洲地区添加一个脚注，因为我不想留下它。
Russ Roberts: But, just as a side note, which you emphasize, which I find extremely interesting, and you've said it implicitly in this last 15 minutes, which is: it's hard to have half a child or 1.4 or 1.7.
拉斯·罗伯茨：但是，正如您所强调的，我觉得非常有趣，并且您在最后 15 分钟中含蓄地说了这一点，即：很难有半个孩子或 1.4 或 1.7。
A society can have 1.4 children per woman, but a woman can have zero, one, two, three, etc. It's an integer problem, a phenomenon--not a problem, a phenomenon.
一个社会每个女性可以生 1.4 个孩子，但一个女性可以生 0 个、1 个、2 个、3 个等等。这是一个整数问题，一种现象——不是问题，而是现象。
And, as a result, it's a large leap sometimes from two to three or zero to one, for sure, and you can't have partial.
因此，有时从二到三或从零到一是一个巨大的飞跃，而且你不能有部分。
It's not an easy--it's not possible.
这并不容易——这是不可能的。
Jesús Fernández-Villaverde: Exactly.
赫苏斯·费尔南德斯-维拉韦德：没错。
And, that's what I was saying before: going from two to three is a big deal.
而且，这就是我之前所说的：从两个到三个是一件大事。
It's a big deal.
这是一件大事。
Russ Roberts: I think one way to help listeners organize your thinking--one's thinking about this, which is helpful to me and [?] thought about until I read your paper--is that, in a way, each one of those choices, those integers, is a different life experience, a different set of motivations.
拉斯·罗伯茨：我认为帮助听众组织思考的一种方法是，在某种程度上，这些选择中的每一个，这些整数，都是一种不同的生活经历，一组不同的动机。
So, a society--again, there will be people who have five and six and seven children, but there are few enough of those that you can almost ignore them.
所以，一个社会——同样，会有人有五个、六个和七个孩子，但这样的人太少了，你几乎可以忽略他们。
The focus in today's world in many countries is the zero, one, two, three.
当今世界许多国家的焦点是零、一、二、三。
So, as you shift the number of people from one to zero or three to two or two to one, you're getting this large reduction in a potentially very short period of time in the fertility rate.
因此，当你将人口数量从 1 转移到 0 或从 3 转移到 2 或从 2 转移到 1 时，生育率可能会在很短的时间内大幅下降。
And, I think it's an interesting way to think about categorizing it, the proportion that have zero.
而且，我认为这是一种有趣的分类方式，即零的比例。
It's obviously something you want to pay attention to, to try to understand, or the proportion that only have one.
这显然是你想要关注、想要理解的东西，或者只有一个的比例。
Two, three starts to get a little more fluid, it's a little different.
二、三开始变得更加流畅，有点不同。
But, it's, I think, a very useful way to organize your thinking.
但是，我认为这是组织思维的一种非常有用的方式。
We're talking about marriage.
我们正在谈论婚姻。
I mentioned the age of first marriage.
我提到了初婚年龄。
Age of first marriage in the United States--the only country I know a little about--has gone from 20-ish, 23, 24 for women to 27, 28.
美国是我唯一了解一点的国家，女性的初婚年龄已从 20 岁左右、23 岁、24 岁下降到 27 岁、28 岁。
Maybe it's higher now, even, in more recent data.
从最近的数据来看，现在甚至可能更高。
Jesús Fernández-Villaverde: Close to 30, yeah.
Jesús Fernández-Villaverde：接近 30，是的。
Russ Roberts: And then, the proportion who have never married has risen dramatically in western countries, United States being one, right?
拉斯·罗伯茨：然后，在西方国家，从未结过婚的比例急剧上升，美国就是其中之一，对吗？
Accurate?
准确的？
Jesús Fernández-Villaverde: Mm-hmm, exactly.
Jesús Fernández-Villaverde： 嗯嗯，没错。
Yeah, exactly.
是的，完全正确。
Over there, what I think the challenge for us as economists is trying to distinguish how many of those are really choices that we should be happy about and how many of those are choices that are being forced by bad economic policy.
在那里，我认为我们作为经济学家面临的挑战是试图区分其中有多少是我们真正应该感到高兴的选择，以及其中有多少是糟糕的经济政策迫使我们做出的选择。
So, I don't--
所以，我不——
Russ Roberts: Give one example of economic policy that's had an impact that you maybe are interested in.
拉斯·罗伯茨：请举一个您可能感兴趣的产生影响的经济政策的例子。
Jesús Fernández-Villaverde: Try to buy a starter house in the United States right now.
Jesús Fernández-Villaverde：现在尝试在美国购买一套入门房。
It used to be the case that you will buy a cheap three-bedroom house in a relatively nice suburb for next to nothing--no, not next to nothing, but a very affordable way with respect to our regular wage.
过去的情况是，你会在一个相对不错的郊区以几乎没有成本的价格购买一套便宜的三居室房子——不，不是几乎没有，但相对于我们的正常工资来说，这是一种非常实惠的方式。
We have made a lot of decisions, a lot of zoning decisions, that has made that very difficult.
我们做出了很多决定，很多分区决定，这使得这变得非常困难。
It basically says--look, and again, this is not about the dynamic programming.
它基本上是说——看，再说一遍，这与动态规划无关。
You are on a date with your girlfriend or your boyfriend, and you are solving the Bellman equation.
您正在与女朋友或男朋友约会，并且正在求解贝尔曼方程。
This is, 'Honey, should we get married this fall or wait for the next spring?' Your partner is saying, 'Well, we need another $25,000 for the down payment.'
这是，“亲爱的，我们应该今年秋天结婚还是等到明年春天？”你的合作伙伴说：“好吧，我们还需要 25,000 美元作为首付。”
Jesús Fernández-Villaverde: 'Let's wait six months.' It's nothing deeper than that.
Jesús Fernández-Villaverde：“让我们等六个月吧。”没有什么比这更深的了。
That's what I really want to tell people.
这就是我真正想告诉人们的。
This is nothing deeper than--and, you probably know friends, relatives that have told you something like that.
这并不比——而且，你可能认识的朋友、亲戚告诉过你类似的事情。
It's so expensive to buy a house in Philadelphia right now that, 'Let's wait six months.
现在在费城买房子太贵了，‘让我们等六个月吧。
I have $25,000 more for the down payment.' There, you have six months where you are not going to be able to have kids.
我还有 25,000 美元作为首付。在那里，你有六个月的时间不能生孩子。
Maybe the fecundity starts going down.
也许生育力开始下降。
Before you realize, you can only have one kid instead of two.
在你意识到之前，你只能生一个孩子，而不是两个。
Russ Roberts: Okay.
拉斯·罗伯茨：好的。
So, let's move to the harder question.
那么，让我们转向更难的问题。
Why should we care?
我们为什么要关心？
Our economies will get smaller, but we don't really care about--it's not the Olympics of who has the biggest economy.
我们的经济将变得更小，但我们并不真正关心——这不是谁拥有最大经济体的奥运会。
We care about our standard living.
我们关心我们的标准生活。
We care more about our human flourishing and not just how much money we have.
我们更关心人类的繁荣，而不仅仅是我们拥有多少钱。
So, we'll be smaller.
所以，我们会变得更小。
Why should this--it's fascinating in and of itself; it's part of the human experience--why should we care?
为什么要这样做——它本身就很有趣；这是人类经验的一部分——我们为什么要关心？
In particular, what is likely to happen, positive and negative, if this doesn't reverse and the world population gets smaller and it gets ever dramatically smaller in the poorest countries?
特别是，如果这种情况不扭转，世界人口变得越来越少，而且最贫穷国家的人口数量急剧减少，那么可能会发生什么，无论是积极的还是消极的？
And, you can say something about Sub-Saharan Africa, sorry, before you answer that question.
而且，抱歉，在回答这个问题之前，您可以先谈谈撒哈拉以南非洲地区的情况。
Jesús Fernández-Villaverde: Okay.
赫苏斯·费尔南德斯-维拉韦德：好的。
So, let's go to Sub-Saharan Africa.
那么，让我们去撒哈拉以南非洲吧。
Okay.
好的。
Everything I have said so far holds for the whole planet.
到目前为止我所说的一切都适用于整个地球。
By the way, it also holds for the Muslim world, for the Islamic world.
顺便说一句，这也适用于穆斯林世界、伊斯兰世界。
I'm going to tell you, since you mentioned Israel a couple of times, Israel is very interesting because, while fertility among Jewish mothers seems to be roughly constant, the fertility among Muslim mothers is collapsing extremely fast.
我要告诉你，既然你多次提到以色列，以色列就非常有趣，因为虽然犹太母亲的生育率似乎大致保持不变，但穆斯林母亲的生育率正在极快地崩溃。
And, I'm talking about the Israel--
而且，我说的是以色列——
Jesús Fernández-Villaverde: In Israel, and I'm talking about the Israel frontiers of 1949.
Jesús Fernández-Villaverde：在以色列，我说的是 1949 年的以色列边境。
I don't want to get over here in any type of big political discussion, but I'm talking about the Muslim women in Haifa, for instance.
我不想在这里进行任何类型的大型政治讨论，但我正在谈论海法的穆斯林妇女。
Their fertility is collapsing extremely fast.
他们的生育能力正在极快地崩溃。
They will be below replacement rate very soon.
它们很快就会低于替代率。
In fact, non-religious Muslim women in Israel are already below replacement rate.
事实上，以色列的非宗教穆斯林妇女的替代率已经低于这一水平。
And, since, I think, 2022, 2021--I'm quoting from my head--the percentage of children born from a Jewish mother in Israel is higher than the percentage of women in fertile age at that time.
而且，我认为，从 2022 年、2021 年开始——我从我的脑海中引用——以色列犹太母亲所生孩子的比例将高于当时育龄妇女的比例。
And, that's just example to point that, basically, fertility among among Jews in Israel is higher than among Muslims.
而且，这只是一个例子，表明以色列犹太人的生育率基本上高于穆斯林。
Now, let's go back to Sub-Saharan Africa.
现在，让我们回到撒哈拉以南非洲。
Data in Sub-Saharan Africa is extremely bad.
撒哈拉以南非洲地区的数据极其糟糕。
All the numbers of the United Nations belong to the Enron School of Accounting.
联合国的所有数字都属于安然会计学院。
They're just completely made up.
他们只是完全化妆了。
So, we really don't know what is going on.
所以，我们真的不知道发生了什么。
Now, for a few countries like Kenya and Congo, we have good surveys--good household surveys--that measure fertility.
现在，对于肯尼亚和刚果等一些国家，我们有很好的调查——良好的家庭调查——来衡量生育率。
In these countries, fertility is collapsing at an incredible speed.
在这些国家，生育率正在以令人难以置信的速度下降。
So, in Congo, in the last 10 years, it has gone from 5.1, which is the world in 1960, to 3.5, which is not that high anymore.
所以，在刚果，在过去的10年里，它已经从1960年的世界5.1，上升到了3.5，这已经不再那么高了。
By doing a very naïve extrapolation--and I emphasize the word 'naïve' three times: naïve, naïve, naïve--this means that Congo will be below replacement rate by the year 2040, which, in demographic terms, is now.
通过做一个非常幼稚的推断——我强调了“幼稚”这个词三遍：幼稚、幼稚、幼稚——这意味着到 2040 年，刚果的人口更替率将低于现在，而从人口角度来看，就是现在。
Kenya, the Nairobi metropolitan area of Kenya, is already below replacement rate.
肯尼亚，肯尼亚内罗毕都市区，已经低于替代率。
These things always happen first in big cities and then spread through the rest of the country.
这些事情总是首先发生在大城市，然后蔓延到全国其他地区。
Dakar and all that metropolitan area in Senegal is already probably below replacement rate.
达喀尔和塞内加尔的所有大都市区可能已经低于替代率。
My conjecture is that fertility is falling very fast in Sub-Saharan Africa.
我的推测是，撒哈拉以南非洲地区的生育率正在迅速下降。
It's just lagging behind the rest of the world because of some structural reasons related with African growth model, but that, basically, Africa is catching up with the rest of the planet, and that there is a very good chance that most of Africa will be below replacement rate by the year 2050 or so.
只是由于与非洲增长模式相关的一些结构性原因，它落后于世界其他地区，但基本上，非洲正在赶上地球其他地区，而且到 2050 年左右，非洲大部分地区很有可能低于更替率。
And, that completely changes how we think about the future of Africa because you are going to have countries below replacement rate at incredibly low levels of income per capita.
而且，这完全改变了我们对非洲未来的看法，因为这些国家的人均收入水平极低，低于更替率。
Russ Roberts: And to go back to our earlier conversation about income and causal mechanisms, normally, I would have said, 'Well, this is good news.
拉斯·罗伯茨：回到我们之前关于收入和因果机制的谈话，通常情况下，我会说，‘嗯，这是个好消息。
They're getting richer, and they're having smaller families.' But that's not what you're saying.
他们变得越来越富有，但家庭规模却越来越小。”但那不是你说的。
It points out that--we talked about income as one having a dramatic impact on fertility, and naturally, economists are going to look at that relationship--but there are a lot of other things going on in the world.
它指出——我们谈到收入对生育率有巨大影响，经济学家自然会研究这种关系——但世界上还发生了很多其他事情。
There's the cultural change, there's this modernity thing you're talking about, there's gender roles, there's cell phones that are keeping people apart from each other and less social, there's social media which builds social interactions with friends and peers at the soccer field and the bar.
有文化变革，有你所说的现代性，有性别角色，有手机使人们彼此隔离，减少社交活动，有社交媒体在足球场和酒吧与朋友和同龄人建立社交互动。
So, it's complicated.
所以，事情很复杂。
But, let's stick with this finding, which is true, that the world is going to get a little bit smaller, maybe very smaller, in the next 30, 40, 50 years.
但是，让我们坚持这一发现，这是事实，即在未来 30 年、40 年、50 年里，世界将变得稍微小一点，甚至可能非常小。
Russ Roberts: Let's now go to the question of, why should we care?
拉斯·罗伯茨：现在让我们来讨论这个问题：我们为什么要关心？
Jesús Fernández-Villaverde: Okay.
赫苏斯·费尔南德斯-维拉韦德：好的。
As you say, there are going to be good things, and there are going to be bad things.
正如你所说，会有好事，也会有坏事。
Okay, so, let's start with the good things.
好吧，让我们从好的方面开始吧。
For instance, many Latin American countries have big cities.
例如，许多拉丁美洲国家都有大城市。
Think about Lima in Peru, Buenos Aires in Argentina, Sao Paulo, that grew very, very fast during the 1960s, the 1970s, and the 1980s because of the big population boom, and those cities are not really bad.
想想秘鲁的利马、阿根廷的布宜诺斯艾利斯、圣保罗，这些城市在 20 世纪 60 年代、1970 年代和 1980 年代由于人口激增而发展得非常非常快，而且这些城市也不是很糟糕。
They have all--
他们都有——
Jesús Fernández-Villaverde: No, they are not very nice places to live because you just have to build shanty towns and a lot of residential neighborhoods that are not very nice.
Jesús Fernández-Villaverde：不，它们不是很好的居住地，因为你只需要建造棚户区和许多不太好的住宅区。
So, you have now the room, once your population is not growing anymore, to upgrade a lot of those neighborhoods, and that will be good.
所以，一旦你的人口不再增长，你现在就有了空间来升级很多这样的社区，这将是一件好事。
We are going to be in a situation where we are going to be able to provide a lot of public services.
我们将处于能够提供大量公共服务的境地。
We are going to be able to have better roads, better infrastructure, etc. So, that, I like, and that will be good for the planet.
我们将能够拥有更好的道路、更好的基础设施等。所以，我喜欢，这对地球有好处。
The problem is that, for good or for bad, we have built very generous welfare states in most countries in the world, surprisingly enough, even in Latin America; and those welfare states cannot handle the big demographic change ahead of us.
问题在于，无论好坏，我们在世界上大多数国家都建立了非常慷慨的福利国家，令人惊讶的是，甚至在拉丁美洲也是如此。这些福利国家无法应对我们面前的巨大人口变化。
I'm going to use my own country, Spain, to give you an example.
我将以我自己的国家西班牙为例。
If you look at government spending since 2007 to today, and you separate it in two bins, everything that goes to retirees, which is basically social security payments and the equivalent of Medicare, but in Spain; and everything else.
如果你看看2007年至今的政府支出，你把它分成两个部分，所有的东西都流向退休人员，基本上是社会保障金和相当于医疗保险的费用，但在西班牙；以及其他一切。
Everything else has not grown since 2007.
自 2007 年以来，其他一切都没有增长。
It actually has gone down a little bit.
实际上已经下降了一点。
At the same time, the population of the country has gone up by eight million people because we have brought a lot of immigrants.
与此同时，这个国家的人口增加了八百万，因为我们带来了很多移民。
Everything that goes to older people has kept growing and growing and growing and growing.
送给老年人的一切都在不断增长、增长、增长、增长。
What are the consequences of this?
这会带来什么后果？
Well, there is no money for infrastructure repair.
好吧，没有钱修复基础设施。
The highways are in bad situation.
高速公路的情况很糟糕。
The highest speed train is not in a very good state.
最高速度的列车状态并不是很好。
A lot of the day-to-day activities of the government cannot refinance, and we could not spend any money on national defense.
政府的很多日常活动无法进行再融资，我们也无法在国防上花任何钱。
Well, that's a problem, and that's going to happen everywhere, and that's going to happen everywhere for a very simple reason: The main voting bloc are going to be people who are retirees or close to retirement, and they are going to say, 'Should we spend a lot of money on education and keeping the infrastructure, or should we spend a lot of money on Medicare?' And I can tell you what is going to happen every place in the planet: They are going to vote for their own interest.
嗯，这是一个问题，这种情况会在任何地方发生，而且这种情况会在任何地方发生，原因很简单：主要投票群体将是退休人员或接近退休的人，他们会说，“我们应该在教育和维护基础设施上花很多钱，还是应该在医疗保险上花很多钱？”我可以告诉你地球上每个地方都会发生什么：他们将为自己的利益投票。
So, we are in a situation where countries like France, Germany, Spain are just not fiscally sustainable in the year 2040.
因此，我们面临的情况是，法国、德国、西班牙等国家在 2040 年的财政上无法实现可持续发展。
I have been thinking a lot about it.
我一直在思考这个问题。
In fact, I'm trying to write something with a friend about Europe.
事实上，我正在尝试和朋友一起写一些关于欧洲的东西。
There is just no way in which we can make this to work in 2040, and this is going to lead to a problem.
我们根本无法让它在 2040 年发挥作用，这将会导致一个问题。
I don't know exactly how this problem is going to turn out to be the case, but when you see a lot of parties putting on the table radical proposals about the future of Europe, I think a lot of that is related with the frustration of many voters about the current state of public finances.
我不知道这个问题到底会如何发展，但当你看到很多政党提出有关欧洲未来的激进提案时，我认为这很大程度上与许多选民对当前公共财政状况的沮丧有关。
Russ Roberts: let me just say one thing, which is: people are living longer because we have innovation in healthcare, and we're also wealthier, higher per capita income, so we're generally healthier.
拉斯·罗伯茨：我只想说一件事，那就是：人们的寿命更长，因为我们在医疗保健方面有创新，而且我们也更富有，人均收入更高，所以我们总体上更健康。
If you don't have kids in 2016, you start having fewer and fewer kids, there's nobody growing up to be the taxpayers to support those retired people.
如果你在 2016 年没有孩子，你的孩子就会越来越少，没有人长大后成为纳税人来支持那些退休人员。
So, the only thing I would add to your argument which I disagree with, at least in some degree, is that it's true that voting blocs tend to vote for their own.
因此，我要对你的论点补充的唯一一点我不同意（至少在某种程度上）是，投票集团确实倾向于投票给自己的集团。
But, if you care about your children, you might feel uncomfortable having them finance your social security and your welfare and your Medicare, especially if you've done pretty well in your life, and, as a result, you'll have some money to transfer to your kids.
但是，如果你关心你的孩子，让他们为你的社会保障、福利和医疗保险提供资金，你可能会感到不舒服，特别是如果你在生活中做得很好，因此，你会有一些钱转移给你的孩子。
I think it's a little more complicated.
我认为这有点复杂。
But what is true is that the political system is a very blunt--it's not nimble.
但事实是，政治体系非常生硬——不灵活。
And so, the ability of it to adjust in fine-tuning ways to these changes is very small.
因此，它对这些变化进行微调的能力非常小。
It'll take a disaster, probably, of various kinds to get people, policies to change in dramatic ways.
也许需要发生各种类型的灾难才能使人们和政策发生巨大的变化。
Jesús Fernández-Villaverde: Second, public debt.
Jesús Fernández-Villaverde：第二，公共债务。
The public debt matters, the size of total GDP [Gross Domestic Product].
公共债务很重要，GDP 总量[国内生产总值] 的规模也很重要。
You'll have countries like Spain with over 100% debt over GDP.
像西班牙这样的国家的债务占 GDP 的比例将超过 100%。
If GDP doesn't grow because the population is shrinking, then it's going to be very difficult to service that public debt.
如果由于人口减少而国内生产总值不增长，那么偿还公共债务将非常困难。
And, finally--I'm sorry to be a little bit gloomy--national defense.
最后——我很抱歉有点悲观——国防。
Okay?
好的？
Iceland, very rich country income per capita.
冰岛，人均收入非常富裕的国家。
Iceland cannot even finance one aircraft carrier task force.
冰岛甚至无法资助一支航母特遣部队。
So, no one cares about finance, about Iceland, and everyone in Iceland is worries on what may invade them.
因此，没有人关心金融、关心冰岛，冰岛的每个人都担心可能会入侵他们。
Unfortunately, we are moving into a very dangerous world with a lot of bad actors, and you need to finance your national defense.
不幸的是，我们正在进入一个非常危险的世界，有很多坏人，你需要为你的国防提供资金。
Russ Roberts: You did not mention the environment.
拉斯·罗伯茨：你没有提到环境。
Presumably, there will be less pressure on the environment?
想必对环境的压力会更小吧？
Jesús Fernández-Villaverde: Yes.
赫苏斯·费尔南德斯-维拉韦德：是的。
I have a little bit of mixed feelings about it.
我对此有一点复杂的感觉。
Let me tell you why.
让我告诉你原因。
So, yes, if you do a very simple decomposition, the answer is yes.
所以，是的，如果你做一个非常简单的分解，答案是肯定的。
Let me tell you what I have in mind.
让我告诉你我的想法。
So, look at the increase in CO2 emission in the planet since around 1990.
那么，看看自 1990 年左右以来地球二氧化碳排放量的增加情况。
CO2 emission per capita has only gone up 9%.
人均二氧化碳排放量只增加了9%。
And, in fact, it has been going down since 2011.
事实上，自 2011 年以来，这一数字一直在下降。
See, that means that all the increase in CO2 emission since 2011 and pretty much all the increase in emissions since 1990 is population growth.
看，这意味着自 2011 年以来二氧化碳排放量的所有增加以及自 1990 年以来几乎所有排放量的增加都是人口增长。
So, as long as the population starts going down, the CO2 scenarios are very different.
因此，只要人口开始下降，二氧化碳的情况就会非常不同。
And by the way, that's one of the reasons why it's so important for the United Nations to get the numbers right because all these integrated assessment models of climate change use the population estimates from the United Nations.
顺便说一句，这就是联合国获得正确数字如此重要的原因之一，因为所有这些气候变化综合评估模型都使用联合国的人口估计。
So, when you follow those, the consequences, the policy implications of those models are also flawed.
因此，当你遵循这些模型时，这些模型的后果和政策影响也是有缺陷的。
But, anyway, so, yes, on that aspect, it's going to be good.
但是，无论如何，所以，是的，在这方面，它会很好。
What worries me a little bit is that the environment is also what economists call a luxury good.
让我有点担心的是，环境也是经济学家所说的奢侈品。
We care a lot about the environment when we are rich.
当我们富有时，我们非常关心环境。
Where does the modern environmental movement start in the world?
世界现代环保运动从哪里开始？
In California.
在加利福尼亚州。
You are living in Santa Barbara, life is great, you have a lot of money.
你住在圣巴巴拉，生活很美好，你有很多钱。
Suddenly, being sure that there is not an oil spill in your beautiful beach is very important to you.
突然之间，确保美丽的海滩没有漏油对您来说非常重要。
You can be in a beautiful beach in a very poor country in Africa.
您可以在非洲一个非常贫穷的国家的美丽海滩上。
Your concern is, 'Can I get something to eat today?' So, as lot of countries are going to be in a very tight fiscal position, it's going to be very, very difficult to go to the voters and say, 'By the way, why don't we fund this new aggressive program to protect the tropical forest?' They're going to say, 'No, no. Log, log, log, log.
你关心的是，“我今天能吃点东西吗？”因此，由于许多国家的财政状况将非常紧张，因此很难向选民说：“顺便说一句，我们为什么不资助这项新的激进计划来保护热带森林呢？”他们会说，‘不，不。记录，记录，记录，记录。
Log, baby, log.
日志，宝贝，日志。
We want to sell the wood because we need to pay for these pensions.
我们想卖掉木材，因为我们需要支付这些养老金。
We need to pay for these social security payments.'
我们需要支付这些社会保障金。”
So, yes, there is a scenario where a smaller population is better for the environment, but there is also a political economic scenario where it's actually not that great for the environment.
所以，是的，在某种情况下，人口越少对环境越好，但在政治经济情况下，人口实际上对环境来说并不是那么好。
And, I have always been a big believer that the best policy to protect the environment is economic growth because, when people get rich, they care a lot about how pretty your garden is.
而且，我一直坚信保护环境的最佳政策是经济增长，因为当人们变得富有时，他们会非常关心你的花园有多漂亮。
Russ Roberts: Yeah.
拉斯·罗伯茨：是的。
I want to close with a tribute to Julian Simon.
最后我想向朱利安·西蒙致敬。
Julian Simon's book, The Ultimate Resource , which I recommend to listeners.
朱利安·西蒙（Julian Simon）的书《终极资源》（The Ultimate Resource），我向听众推荐。
We haven't talked much about that over the years on this show, but you point out in a recent paper that in 1960, South Korea had a little over a million births.
多年来，我们在这个节目中没有过多谈论这一点，但您在最近的一篇论文中指出，1960 年，韩国的出生人口略高于 100 万。
In 1960, a million births in South Korea.
1960年，韩国有100万新生儿。
In 2023, that number is 230,000.
到 2023 年，这个数字将达到 230,000。
So, it's a quarter, roughly, of what it was.
所以，这大约是原来的四分之一。
So, there's fewer South Koreans in 20 years who go to college and could come up with something creative.
因此，20 年来，上大学并能想出创意的韩国人越来越少。
Julian Simon's view of the world was that population growth was basically good.
朱利安·西蒙的世界观是人口增长基本良好。
He had some caveats, of course, but he viewed that the great ultimate resource was our creativity as human beings.
当然，他有一些警告，但他认为最大的终极资源是我们作为人类的创造力。
And when you have fewer people, there's going to be, in the right-hand tail, fewer people.
当你的人数减少时，右侧尾部的人数也会减少。
A question of how fat that tail is, you write about that.
关于那条尾巴有多肥的问题，你写到了。
But, innovation and creativity will be less, presumably, in a smaller world unless we get along better in a smaller world, which would maybe make it easier to sit around and write symphonies.
但是，在一个更小的世界里，创新和创造力大概会减少，除非我们在一个更小的世界里相处得更好，这也许会让我们更容易坐下来写交响曲。
I don't know.
我不知道。
We got AI [artificial intelligence] coming, who knows?
我们的人工智能即将到来，谁知道呢？
Talk a little bit, if you want to, about that phenomenon.
如果你愿意的话，可以谈谈这个现象。
Jesús Fernández-Villaverde: Sure.
赫苏斯·费尔南德斯-维拉韦德：当然。
Yeah.
是的。
No, so, basically, the idea is, how many Einsteins you are going to have in a population?
不，所以，基本上，这个想法是，人口中有多少个爱因斯坦？
Well, to some degree, it depends on how many children you have.
嗯，在某种程度上，这取决于你有多少个孩子。
And, when you have a much smaller population, you are going to have a lower chance of having a top person.
而且，当你的人口少得多时，你拥有顶尖人物的机会就会更低。
So, for the undergrads, I use a slightly more mundane example, which is: Why is Italy's soccer team so bad lately?
那么，对于本科生，我用一个稍微平凡一点的例子，那就是：为什么意大利足球队最近这么糟糕？
Well, because there are just so much fewer Italians.
好吧，因为意大利人少得多。
So, if you are trying to select the best 22 soccer players when you have 300,000 Italians being born every year, you are going to have a much worse team than when you used to have one million Italians being born every year.
因此，如果你在每年有 30 万意大利人出生的情况下试图选出最好的 22 名足球运动员，那么你的球队将会比以前每年有 100 万意大利人出生时糟糕得多。
So, your soccer team is just going to be much worse on average.
所以，你的足球队的平均水平会更差。
Well, substitute soccer players for top scientists, top artists, top creative people in any dimension that you want to have.
好吧，用足球运动员代替你想要拥有的任何维度的顶尖科学家、顶尖艺术家、顶尖创意人士。
Now, you're absolutely right that we can try to move the needle in other aspects.
现在，你说得完全正确，我们可以尝试在其他方面取得进展。
For instance, I'm a big lover of classical music.
例如，我非常喜欢古典音乐。
One of the things that surprises me the most is the incredible amount of top performers that come from Iceland, which, coming back to Iceland, there are only 350,000.
最让我惊讶的一件事是，来自冰岛的顶尖人才数量惊人，而回到冰岛后，只有 35 万人。
So it means that you can do something.
所以这意味着你可以做某事。
You can say, 'Look, let's take[?] whoever we are going to have, and we are going to work a lot with that group of people.' But, at the end of the day, no matter how hard you try, yes, you are going to have a situation where we are just not that many of us.
你可以说，“看，让我们选择[？]我们想要的任何人，我们将与这群人一起工作很多。”但是，归根结底，无论你多么努力，是的，你都会遇到这样的情况：我们只是人数不多。
And, I think that's a miss.
而且，我认为这是一个错过。
And, the second point I want to emphasize--I think that people don't get this right, and let me tell you what I mean by that.
而且，我想强调的第二点——我认为人们没有理解这一点，让我告诉你我的意思。
They say, 'Oh, we are eight billion people.
他们说，‘哦，我们有八十亿人。
We are going to follow to seven billion.
我们将追随到 70 亿。
It's okay, we are going to be two billion people less.' No, no, no, no. Remember, as long as we are below replacement rate, let's continue going down.
没关系，我们的人口将会减少 20 亿。”不，不，不，不。请记住，只要我们低于替代率，我们就继续下降。
It's not that we stop at seven.
这并不是说我们七点就停下来。
So, I have this exercise where, with the current--it's a scenario; it's not a forecast.
所以，我有这个练习，在当前情况下，这是一个场景；这不是预测。
I want to emphasize the word 'scenario' because it means if behavior doesn't change.
我想强调“场景”这个词，因为它意味着行为不改变。
So, this is just a pure thought experiment.
所以，这只是一个纯粹的思想实验。
But, in this thought experiment, Thailand right now is around 62 million people.
但是，在这个思想实验中，泰国目前约有 6200 万人口。
At the current fertility rate, in 200 years, Thailand will be 600,000 people.
按照目前的生育率，200年后，泰国人口将达到60万人。
So, we are talking about going from 62 million to 600,000.
所以，我们正在讨论从 6200 万增加到 60 万。
Just think about the amount of societal rearrangements that we need to go from 62 million to 600,000.
想想我们需要进行多少社会重组，从 6200 万增加到 60 万。
But in 400 years, Thailand falls below the bare minimum biological threshold for survival.
但 400 年来，泰国的生存率已经跌破了最低的生物阈值。
You are not going to have enough genetic variation within the population to keep the population alive.
种群内不会有足够的遗传变异来维持种群的生存。
So, basically, we are talking that, in 400 years, at the current fertility rate, Thailand disappears.
所以，基本上，我们说的是，按照目前的生育率，400 年后，泰国就会消失。
And I think that a lot of people, when I tell them fertility is below replacement rate, they say, 'Oh, good, that means we are going to have a couple less million people living in New York.
我认为，当我告诉很多人生育率低于更替率时，他们会说，‘哦，很好，这意味着生活在纽约的人口将减少几百万。
Great.
伟大的。
That means there will be less traffic in Holland Tunnel.' No, no, no, no. At 1.57, it means that eventually the United States becomes an empty country.
这意味着荷兰隧道的交通量将会减少。不，不，不，不。 1.57，意味着美国最终会成为一个空国家。
Now, it's a scenario .
现在，这是一个场景。
A lot of things are going to counterbalance, so I'm not saying that we are--and I really don't want to be on the side that says, 'We are running into extinction,' because I don't think that's the case.
很多事情都会相互抵消，所以我并不是说我们是——而且我真的不想站在说“我们正在走向灭绝”的一边，因为我认为情况并非如此。
But, I don't think that people get the point: This is not going down a little bit and stabilizing.
但是，我认为人们没有明白这一点：这并没有一点点下降并趋于稳定。
At the current scenario, it's a continuous drop.
从目前的情况来看，这是持续下降。
Russ Roberts: And the last thing--we'll close with this--is that: you talk in the paper about, in markets, there are feedback loops that offset changes.
拉斯·罗伯茨：最后一件事——我们将以此结束——是：你在论文中谈到，在市场中，存在抵消变化的反馈循环。
And you suggest that there aren't so many obvious ones for population.
你认为人口方面没有那么多明显的问题。
I think there are .
我认为有。
I think the cultural changes of modernity are going to be challenged when these processes start to have these large effects.
我认为，当这些过程开始产生巨大影响时，现代性的文化变革将受到挑战。
So, they're blunt, again: it's not the smoothness of price adjustment.
所以，他们再次直言不讳：这不是价格调整的平滑性。
But I do think that the world will react to this in not a small way.
但我确实认为世界将会对此做出不小的反应。
It will be some big changes.
这将会发生一些大的变化。
Jesús Fernández-Villaverde: No, no, no; that may be true.
赫苏斯·费尔南德斯-维拉韦德：不，不，不；这可能是真的。
I mean, let me give you a concrete example.
我的意思是，让我给你举一个具体的例子。
In the Commonwealth of Pennsylvania, where I live, it's already very difficult to win a statewide election if the Amish do not support you because the Amish has been growing so much that now they are a pivotal voting block.
在我居住的宾夕法尼亚州，如果阿米什人不支持你，赢得全州选举就已经非常困难了，因为阿米什人一直在增长，现在他们是一个关键的投票群体。
At the current speed, I always make the joke that if Pennsylvania continues being a swing state, it may be the case that the Amish Bishop Conference is the one who effectively elects the next President of the United States in 2060, because they will determine, you know, on which side Pennsylvania will go.
按照目前的速度，我总是开玩笑说，如果宾夕法尼亚州继续成为一个摇摆州，阿米什主教会议可能会有效地在2060年选举下一任美国总统，因为他们将决定宾夕法尼亚州将走向哪一边。
Now, it's kind of a joke, but it makes the point.
现在看来，这虽然是个笑话，但它却说明了问题。
Yes, you are going to have a--I'm sorry, I know I'm going over time a little bit--but we didn't talk much, for instance, about the difference between the fertility rates of religious and secular people.
是的，你将会有一个——对不起，我知道我有点过时了——但我们没有谈论太多，例如，关于宗教人士和世俗人士的生育率之间的差异。
The fertility of religious people has not fallen.
宗教人士的生育率并未下降。
So, you can have a society that becomes much more religious.
因此，你可以拥有一个变得更加宗教化的社会。
Now, that depends also on the persistence of religiosity.
现在，这还取决于宗教信仰的持久性。
Just because I'm very religious doesn't imply that my kids need to be religious.
仅仅因为我非常虔诚并不意味着我的孩子也需要虔诚。
But, if persistence is high enough, maybe what will happen is that, in 200 years, we will have a much more religious United States or a much more religious planet, and that will push back fertility to a replacement rate.
但是，如果坚持程度足够高，也许200年后，我们将拥有一个更加宗教化的美国或一个更加宗教化的星球，而这将把生育率推回到更替率。
But, who knows?
但是，谁知道呢？
It may be the case.
可能是这样。
I put positive probability.
我把正概率。
Let's see what happens.
让我们看看会发生什么。
Russ Roberts: My guest today has been Jesús Fernández-Villaverde.
拉斯·罗伯茨：今天我的客人是赫苏斯·费尔南德斯·维拉韦德。
Jesús, thanks for being part of EconTalk.
天啊，感谢您参与 EconTalk。
Jesús Fernández-Villaverde: Thank you for inviting me.
Jesús Fernández-Villaverde： 谢谢您邀请我。
It was a real pleasure.
这真是一种乐趣。