Greetings, Bryan Caplan!

I tweet under the handle @MoreBirths on Twitter/X. We are both pro-natalists and your book Selfish Reasons to Have More Kids (which I am holding in my hands as I write this) was the most important book of 2011 and in my estimation the most important thing you've ever written. I'll have to have you autograph my dog-eared copy at some point. I am friends with your colleague Robin Hanson, and I live locally in Rockville Maryland, so hopefully I really will have a chance to meet you and discuss our common pro-natalism.

Here's my thought which is vastly important and which I am not sure you have considered:

Seeing your cover art through the lens of the great low birth rate crisis that is devastating global economies, I don't see a cool futuristic Jetsons-style city. I think "OMG, that is Seoul or Shanghai or some other East Asian city with a TFR of 0.5 to 0.6 births per woman. If we build like that, population will crash even more, and civilization will be screwed."

Here are a few posts and threads I've written about urban high-rises and the ultra-low fertility that results. Please graciously look through threads (they aren't long) and consider amending your argument and cover art a bit.





I fully agree that building is good and high housing prices crush fertility. But it matters dramatically what we build. If we build Atlanta-style (first post in the thread) fertility will be fine and we will be okay. If high-rises and ultra-dense housing configurations result, civilization will be crushed through Korean-style demographic collapse.

This is not some Korean quirk: the lower fertility associated with higher density is like an iron law of demography, true almost everywhere and at almost every time in history. And we can't just rely on markets to sort this out.

How does this square with economics? Don't we believe free markets will solve everything? Not in this case. First of all, the devastating signals of a collapse in fertility (and ensuing civilizational collapse) are hidden, removed from normal economic calculus and separated in time by a generation or more. But ultimately this devastation is real and dramatic.

Is the collapse in fertility that results from overly dense housing a tragedy of the commons? Maybe. Or maybe we need a new economic principle to describe the short-term/long-term mismatch (where we don't take into account long-term costs such as demographic collapse) that may result for the course we are taking.


Bryan, you are correct in a lot of ways. It is good to build more housing to alleviate crushes. If that ends up being more suburbs, and opening more farmland and exurbs for homes we will be okay demographically. But if we throw up high rises, Asian-style, we will be devastated demographically. That happened basically through free markets and it's an awful market failure from which the affected countries may not recover.

The problem with housing type is that housing can last for hundreds of years once it is built. Young people are eerily drawn to cities, where they will stay and have very low fertility. I was in Japan for 10 days (in an Airbnb house on the edge of Tokyo) with my family in September and I saw this. Tokyo has the lowest fertility in all of Japan, but they keep building more high-rises and young people are continually drawn to them. So, Tokyo isn't depopulating, the rest of Japan is. Young people leave the higher-fertility countryside for lower fertility Tokyo -- a depopulation conveyor belt that is crushing the economy and the nation. I wrote about how Japan's stagnancy is down to demographics in this viral thread (3.2 million views so far).


Housing rules that favor limited density are critically important for fertility. If fertility crashes, at it is doing, it will take down everything else. Single family zoning seems like a violation of free markets, but it addresses the greatest market failure in world history, density-driven demographic collapse. And ultimately it forces people and companies and economies to spread out, resulting in a society that is demographically sustainable rather than collapsing.

Bryan, if you are still reading, I am so grateful! DM me at @MoreBirths and I'd love to discuss more or we can meet up. You are a hero for your pro-natalism, and I think this book can be dramatically improved by taking that into account!

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What's the first world's third greatest missed policy area?

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What no hardcover?

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Ha! Je comprends le français!

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I dont know how to preorder the book to sweden without great imports fees sadly.

I wish you luck though

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Cover reminds me of Bruce Mccall covers.

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I loved Open Borders and passed it on to my daughter and I just preordered this one. Thanks for making these books.

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Is there going to be a hardcover? I will (pre)order that

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not remotely related but I came across this- https://www.noahpinion.blog/p/plentiful-high-paying-jobs-in-the which argues that due to comparative advantage, even if AI can do any given job better than humans, humans would still have jobs due to opportunity costs of using the AI. This argument is fairly convincing to the extent of my layman's understanding of economics so I'd be interested to hear what you have to say about it

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Already there

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Will pre-order when I get paid! Thoroughly enjoyed "Open Borders" e-book, can't wait to read this one from digital cover to cover!

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I've preordered it! 😄

I can't wait.

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Pre-ordered. Here’s the book’s description: Why are housing prices in America so unbelievably high, especially in the country's most desirable locations? The superficial answer is “supply and demand,” but the deep answer―the reason supply is so low―is a regulatory system that treats developers like criminals.

In Build, Baby, Build: The Science and Ethics of Housing Regulation, economist Bryan Caplan makes the economic and philosophical case for radical deregulation of this massive market―freeing property owners to build as tall and dense as they wish. Not only would the average price of housing be cut in half, but the building boom unleashed by deregulation would simultaneously reduce inequality, increase social mobility, promote economic growth, reduce homelessness, increase birth rates, help the environment, cut crime, and more.

Combining stunning homage to classic animation with careful interdisciplinary research, Build, Baby, Build takes readers on a grand tour of a bona fide “panacea policy.” We can start realizing these missed opportunities as soon as we abandon the widespread misconception that housing regulation solves more problems than it causes.

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Done! Looking forward to it.

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Mar 19·edited Mar 19

Bryan, if you could work with the publisher to allow purchase/preorder on Google Play Books, that would be great. While it's not as popular as Kindle, it's a much less censorious platform in my experience. If I'm going to pay ebook marketplace fees, I'd rather it be to a company (or a division of a company) that doesn't engage in viewpoint discrimination.

Not to mention the fact that one of the few things Google Play Books does well is graphic novels/comic books given most customers don't read the content on e-ink displays, allowing for a visually better experience.

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Google doesn’t do viewpoint discrimination? Please Google “Gemini and bias”

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