Response to the Comments on Open Borders

I posted a (significantly improved) version of my review of Bryan Caplan’s book Open Borders on LessWrong and the EA Forum. It was also linked to and discussed on Marginal Revolution. I got enough thoughtful responses that I thought it was worth making a comment response post.

From my email

From Fergus McCullough, in my email:

“I don’t have any answers to what I’m about to say… it’s noticeable that this guy emphasises brain drain from secondary regions of China. So there’s some margin at which there can be (harmful?) brain drain from such regions. Not sure whether this conflicts with the benefits of within-country migration that economists talk about, and you mention in your piece. Also I wonder whether migration might be bad for a country if its population is shrinking, e.g. people leaving an already declining Germany might accelerate population trends there and risk quite a bad outcome. I don’t know whether we can even know what that would look like.”

This was my response:

“I didn’t mean to imply brain drain is not a problem. Just that it’s kind of like worrying about overpopulation on Mars for a lot of countries. A very poor country might have capitalised on only a few percent of its available (say) medical talent. Surely if China loses a lot of talent to emigration, it can just allow in more immigrants. The only possible loser is very poor countries, which were really not that nice to begin with. I think this concern is most respectable in the context of people talking about somewhere like Croatia, which has lost 10% of its population to outward EU migration. But for someone outside the EU, it’s extremely difficult to move to Croatia! Many would if they could. And again, the pool of people with the ability to do things is not fixed. I didn’t bring this up [in the review] but there is also a revealed/stated preferences thing going on here. People have a stated preference for “maintaining your heritage” and living in harmony with the land in an idyllic town. But in practice, people usually choose to move to the city and get wealthy over the idyllic Croat town. So insofar as there are policies to reduce brain drain, it feels like this elite aesthetic preference being imposed on everyone else.” 

From Tyler Cowen:

“I often say to Bryan “How about open borders for Israel and Taiwan!?” I don’t think he has a good answer.”

I kind of touched on this in the review, when I mentioned how the real risk with immigrants’ political views is the tail risk of fringe parties and political breakdown, not a slight shift in the median voter. And a natural corollary of this is that open borders are worse for countries that are politically unstable, or whose stability is particularly dependent on the ethnicity or political beliefs of their citizens.

David Henderson wrote an entire blog post responding to my review! He writes:

“I realized that this [the argument that open borders would increase animal suffering] is not a good argument at all. Let’s say we could reduce the demand for factory farming by imposing draconian regulations that reduce Americans’ per capita income by 80 percent. Would that justify those regulations? I think not. So then how, if we accept the other parts of Bryan’s argument, can we justify, based on reducing factory farming, draconian immigration restrictions to keep many people’s income 80 percent lower than otherwise. Even if you think regulation is justified to reduce factory farming, shouldn’t the regulation be aimed, not at keeping people poor, but at reducing or ending factory farming?”

Enough people were confused by this that I really should have made it clearer. I’m not saying that open borders are a bad idea because of animal suffering. I’m saying that, if we think that eating meat is wrong at all, then open borders is less good of an idea than it otherwise would be. The response to this has been a reductio: “Doesn’t this imply that it’s actually good to kill people or make them poor?”. But this only shows that the amount that animal suffering impacts these arguments is somewhere between “not at all” and “humanity is terrible and you should feel bad”.

From the EA Forum

From tessa:

“You’ve identified my two main frustrations with the book: US-centrism and the attitude that there exist no substantial objections to open borders (rather than a more measured argument that the benefits outweigh the harms). There were a few panels towards the end of the book which typify this for me.

I, uh, I don’t think “the only thing that stands in the way of opening the [US-Canada]  border is sheer political apathy”. Québecois separatists were ransoming politicians within my parents’ lifetime, and Québec nearly separated in 1995. I don’t expect most Americans to pay attention to the fragility of Canadian federalism, but it’s super frustrating to see someone be so confident that there is no possible argument against their position!

This book contained several interesting economic arguments (e.g. “migration good for the economy = big countries do better”, as you pointed out) but enough credibility-straining overconfidence that I haven’t been recommending it.”

Tsunayoshi writes:

“You mention “It’s probably the case that the biggest harms from immigration come from people irrationally panicking about immigration, but (surprise!) people are in fact irrational.”. 

From an EU-perspective, the effect seems pretty clear: After the refugee crisis 2015-2016 there have been numerous cases of populist right-wing parties gaining support or outright winning elections after running on anti-immigration platforms: to name just a few: the Lega Nord in Italy became part of the government, the FPÖ polled at their highest in 2016,  and anti-immigration sentiment was at least influential for Brexit. These are arguably outcomes that substantially weaken political institutions and lead to worse governance. 

This kind of backlash from some parts of the established population happens at moderate levels of immigration. We should expect it to be much stronger when immigration would be much higher under an Open Borders system, and account for the effects of that.”

I agree that the effects of immigrants on politics are less uncertain than I led on, and the right-wing backlash seems to have been fairly reliable.

From LessWrong

Aphyer writes:

“Without commenting on the rest of your post, I am extremely suspicious of your climate change argument.

When the 2008 crisis led to an extended recession, I do not recall many people saying ‘actually this is good, as reduced economic activity due to recession will improve the climate’. When Haiti got hit by natural disasters, lots of people died, and society and the economy collapsed, I again recall very few people saying this.

If you are a single-issue climate change voter, and genuinely do consider everything via a lens of ‘good things are actually bad because they will hurt the environment, and bad things are actually good because they will help the environment’, I withdraw this criticism.

But if your first thought when you read a newspaper report about falling murder rates is not ‘oh no, all those people continuing to live First World lives, think of the environment’, it seems disingenuous to expect Caplan to do the same.”

Man, people really overinterpreted my argument about climate change… I do not think that climate change is so bad that recessions, natural disasters, and poverty are actually good! Just that, if we put any value on the climate whatsoever, these things are not as bad as they otherwise would be. If we were on the fence about whether natural disasters were a bad thing (which of course we’re not) then the climate change argument may put us over the edge. This is the relevance of climate change to open borders. Let’s say that climate change and other forms of pollution make the harms of open borders 10% greater. Then the benefits would have to absolutely completely outweigh the harms to a greater extent than they otherwise would. My steelman of these commenters is that my points about climate change and animal welfare are a general argument against basically every proposed policy change that makes people better off, and since they’re so general there’s no point bringing them up. And I probably won’t again, but this review was the first time I wrote about proposed policy changes!


“One weirdly striking thing missing from Caplan’s book and this review is one of the most common objections people have to mass immigration: loss of their dominant culture.

Given how much anti-immigration rhetoric focuses on precisely this argument, it is bizarre for Caplan not to take it seriously and makes me concerned he is living in an academic bubble so heavily biased towards pro-immigration arguments that he’s failed to even acknowledge it as a concern.

Consider that many people in the UK/Europe bemoan that their major cities have entire sections with no native speakers, are full of Arabic/Polish/Chinese signage or whatever, and bear no resemblance to the place they grew up in. 

Lots of anti-immigrant US groups online also fear the the displacement of Christianity (or Judeo-Christian culture) as the major value system in America.  A less controversial version of this argument may just be that people value shared continuity/history with their fellow countrymen and enjoy having a sense of kinship with people who share their cultural background.

I’m not saying this is the best argument, nor am I agreeing with it, but it is extremely common.”

I agree that Caplan lives in an academic bubble (as does Caplan himself). I think the fact that this concern doesn’t get brought up is his Americacentrism in disguise. He identifies American culture to a large extent with Western culture, which looks to be on course to dominate the world. But people concerned about the effects of immigration on culture are often from the small pockets of regional cultures that are now mostly extinct in the Anglosphere. For example, there was once a Puritan Massachusetts culture, and we are probably now witnessing the death of the Appalachian honour culture, to be replaced with Western culture, vaguely corresponding to America/capitalism/globalisation/liberalism. This point in Caplan’s thinking is discussed in-depth by Scott Alexander in How The West Was Won.

I am from Ireland, which is a place that had a very distinct culture, which has been decimated and almost entirely replaced with global Western culture. And… I have mixed thoughts about it. These sorts of issues are not well suited to the format of Caplan’s book. I hope someone writes a sequel in which they talk about the effects of immigration on culture in a more qualitative way, not relying on these “People are worried about the death of American culture, but look at how many foreigners are drinking Coca Cola, hardy har har” arguments.


“The US is famous for being culturally and politically polarized. What does it even mean for immigrants to be “barely different from natives” politically? Do they have the same (polarized) spread of positions? Do they all fit into one of the existing political camps without creating a new one? Do they all fit into the in-group camp for Caplan’s target audience?”

“Barely different from natives” means that, on a test designed to measure how politically left or right people are in America, immigrants, on average, score very similarly to natives. I don’t know if polarisation is higher or lower among immigrants. I admit this methodology sucks, and I admit that political science sucks in general.


“Was there really that much immigration in 18th century Edinburgh? And in terms of agglomeration, I’m sure it was denser than, say, the highlands of Scotland, was it really that much compared to other cities in Britain?”

I live there so I should probably know this! I’ve heard that a lot of intellectuals came from the islands to Edinburgh, which was almost like moving country. The older parts of Edinburgh are really rather high-density so I suspect it was only matched in density by a few other British cities at the time.

Dzoldzaya left a long and thoughtful comment, but I’ll only respond to one part of it here:

“”The countries that are the closest to having open borders are the Gulf states; they have many migrant workers from countries like Bangladesh and Sri Lanka.” This seems the strangest line of the review. Depending on your definition, I’d say that the Gulf States have the opposite of open borders. They previously had targeted immigration policies allowing other Arabs from the MENA region to work there, then they caused too many social problems, so the Gulf countries threw them all out, and invited targeted immigration from a few specific poor countries (with people who didn’t speak Arabic, and therefore wouldn’t get involved in local politics). There is actually a decent amount of social mobility in these countries (a strangely high proportion of my friends are Gulf-state Indians based in Europe), so I wouldn’t be too worried about long-term racial segregation. If you see this story of poor South Asians taken out of poverty by working in the gulf, the Gulf States are a strong argument for a very ‘non-open borders’ way of doing mass immigration: inviting large numbers of migrants to come to a country on guest worker schemes, with very limited rights. Although these migrants have no social support, and can be thrown out on the whim of the recipient country, they can make loads of money compared to back home. I actually think this might be a really good idea, and this is also similar to what Chinese cities do with domestic migration, which avoids parts of Beijing and Shanghai turning into huge shantytowns. However, as you mention, having a ‘second-class’ population sits poorly with European norms and sensibilities.””

This comment made me realise there are two meanings of the term ‘open borders’, which I had been using interchangeably. One is where you take the number of people who immigrate to the country, divide by the number of people who want to immigrate, and the closer this number is to one the more open your borders are. The other meaning is unrestricted or unregulated immigration. The Gulf States have the former but definitely not the latter. I know very little about this topic; the point about the Gulf States being the country with the closest thing to open borders I got from an interview with Caplan.

From Marginal Revolution

From an anonymous commenter:

“”Until the 1920s, the US had de facto open borders, and this is another thing that I wish Caplan had dug into more. Did this work? How did infrastructure cope? What was the wage premium of immigrating?”

Property owners and employers were free to discriminate, criminality could be brutally punished, vagrancy was a crime, no or extremely limited welfare. No public education. English was the lingua franca–you spoke it, or stayed at the bottom of the ladder. Much, much lower population with lots of empty land–if you weren’t willing to be a settler the US was actually pretty inhospitable. Unless you were Irish or Italian and willing to jam into an Eastern seaboard city.”

I admit that the past sucked, but see above. In that sentence I wasn’t talking about the rights of immigrants nor anyone else: I just meant to say that, if you really wanted to go to America, you almost always could before the 1920s. Someone brought up the Chinese Exclusion Act of 1882, which I probably should have mentioned, but I suspect that the American administrative state was so minimal at this time that it was easy to get around, which Wikipedia appears to agree with.

Another anonymous commenter:

“Good to know that budding intellectuals can be lured in by fun cartoons.”

Hell yeah we can!


“I find the critique that it’s overly US-focused to be a good one. A second would be the argument of reciprocity. How many Americans would retire to the Caribbean if it were as simple as retiring to Florida?”

I didn’t really discuss this because the gains to people from poor countries are much greater, but yes, it being easier to travel to other countries and/or retire to ones where you wouldn’t necessarily work would be great.

P.S. My review has now been endorsed as being good and fair by Bryan Caplan and Patrick Collison.

One thought on “Response to the Comments on Open Borders

  1. Interesting read. I see the case for and against open borders mainly boild down to a class issue. What this means is that people generalize from their own experiences of “diversity” and assume open borders means more of that. And this might vary wildly between elites and commoners. For elites who dwell mostly in academia and high status business enviroments diversity is great. All it means is that people are mostly rational and cultural differences boil down to minor differences in matters of taste. Their genuine experience can be that diversity is a strength and they can be completely good-willed in advocating for more diversity for everyone else as well.

    Then again the working-class or commoners (the lower IQ-segments of society) can have an equally genuine experience in the opposite direction. This could be due to several reasons. Maybe they rely more on a shared culture and less on rationality. If this is the case for both the immigrants and locals, what people experience is just less “smoothness” and predictability when dealing with people. Also the commoners might end up with immigrants of a similiar social class, who in turn rely mostly on their local culture, which in turn would Elites could be immune to this problem they have a shared culture based on rationality that´s more global and less reliant on local norms.

    If the disagreement between commoners and elites is based on different experiences.


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