Open Borders: A Review of Bryan Caplan’s Book

Caplan's case for limitless immigration is compelling but overconfident

Bryan Caplan is an economist at George Mason University known for his wacky libertarian views about various social and political issues (especially education). Open Borders: The Science and Ethics of Immigration is his latest book, which is in the format of a graphic novel illustrated by Zach Weinersmith of SMBC fame. The graphic novel format works really well. The art style is cute and non-fiction graphic novels are grossly underrated (some favourites of mine are Maus and Logicomix). Realistically, most people are not going to read a regular book about the economics of immigration. But this way Caplan can lure us in with fun cartoons!

Caplan really does believe that there should be no restrictions on immigration whatsoever, and that’s exactly what his cartoon representation argues for in this book. The basic argument goes like this: People should, in general, be allowed to make decisions that they think will improve their lives, assuming they’re not hurting anyone. Moving to a new country is exactly such a decision. Since immigrants often move in search of work, moving is associated with a massive increase in economic prosperity. By moving to the US and receiving no additional training or education, the average citizen of a developing country can expect their income to increase fivefold; and for countries like Nigeria, tenfold. This is because developed countries are safer and have better quality institutions, so immigrants are more productive in them. Also, the opportunity cost of workers in rich countries is higher, hence why service workers like gardeners are so much more productive there. The gains are so vast that a standard estimate is that open borders would double world GDP. Yet rich countries continue to restrict immigration, sometimes through formal caps, and sometimes through complicated bureaucracy and paperwork which at best dissuades people from entering and at worst makes it literally impossible (like rejecting you for not filling out the middle name section on a form when you don’t have a middle name). Some of the arguments against immigration are xenophobic or racist, but many are legitimate concerns brought up in good faith. But most of them are not borne out by careful consideration of the evidence. The consensus among economists is that immigration does not generally decrease natives’ wages. Nor does it lead to an increase in poverty, crime, or a significant strain on the welfare state and social services. While the data about this are more unclear, immigrants are barely different from natives in their political views, and they adopt a lot of the cultural values of their destination country. Hence, the book argues, the contrary considerations are not enough to overwhelm our initial presumption in favour of allowing people to move, and so we should have open borders.

🎵 I want to be in America, I want to be in America 🎵

Open Borders is an extremely America-centric book. This is something that frustrates me about a lot of nonfiction. Caplan justifies his focus on the US by saying that his audience is mostly American and that that’s where the highest quality data exists. But in this case, the book makes a way narrower argument than it sets out to. By focusing primarily on America, the case is made stronger than it otherwise would be. Immigrants commit more crimes than native-born Europeans but fewer crimes than native-born Americans. Immigrants to the US assimilate unusually well. In a shocking turn for the Cato Institute, one of their researchers says that this is just because European countries have more highly regulated labour markets. 

Focusing so much on the US is bizarre because the European Union has open borders between its member states! Surely analysing whether this has gone well is the single most convincing piece of evidence about open borders. Ireland is 17% foreign-born, a higher proportion than the US, and from eyeballing the data it looks like the immigration rate to Ireland has nearly quadrupled in the last 20 years. Meanwhile, it’s doing pretty well and looks to be on track to become one of the richest places in the world. This would seem like a major success story of immigration. Yet Caplan only talks about the EU for a few panels toward the end of the book. This level of parochialism isn’t justified. 

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?

Open borders would be the largest social transformation ever, and there isn’t even very much research about it. We should be extremely humble about our views on complex topics, and the downsides of open borders, if we are wrong, are quite significant. Caplan is unusually scrupulous about making sure his claims are backed up by the data. His book The Case Against Education is one of the most meticulously researched books I have read. So, it was a bit disappointing that there weren’t more margins of error attached to his claims. How confident are we that open borders would really double world GDP? 10%? 50%? 90%? After reading about the replication problems in economics and the colourful uses of statistics to get one’s desired conclusion, I don’t find these projections very convincing. More convincing would be natural experiments and case studies, although I mentioned that the EU - the most compelling such example - is not talked about much.

Inertia is the most powerful force in the universe

Gallup finds that more than 100 million people want to migrate to the US. 750 million say that they would leave their home country if they could. But we have reason to doubt that people would actually act on this. This makes open borders more palatable to those that are sceptical of immigration; it wouldn’t be as different to the status quo as you might expect. During the Greek financial crisis, only 3% of the Greek working-age population left, at a time when the unemployment rate was 27% – and Greeks have more than a dozen prosperous destination countries to choose from with no paperwork involved! Inertia truly is the most powerful force in the universe. Caplan’s defence of his high estimates of the number of future immigrants is that, once the ball gets rolling, more and more people from a particular country will move. Historically, immigration from Puerto Rico to the US was lower than you would expect given the difference in economic opportunity, but then Puerto Rican communities formed in many US cities, and more and more people moved. So insofar as truly huge numbers of people would immigrate, they would probably do it over a long period of time. 

A corollary of migration being good for the economy is that big countries should do better, because they don’t have internal barriers to movement (there are internal barriers to moving within China; I haven’t looked into this yet). How much of India and China’s economic growth is a result of the fact that they’re really big? When Caplan pointed this out, I was surprised I hadn’t thought about it before. This is discussed in one panel on one page, but I would like to see the argument developed more. Do more populous countries have greater growth in the long run? If so, this points us in the direction of open borders. Caplan talks about what Lant Pritchett calls ‘zombie economies’ – economies kept alive by restrictions that forbid people from leaving. A large fraction of the US has been declining in population for decades, yet we would regard it as absurd to say that people shouldn’t be allowed to leave Nebraska because doing so would go against Nebraska’s interests.

The argument from “more people are better”

In One Billion Americans, Matt Yglesias argues for large-scale population growth, partially through immigration but mostly through an increase in fertility, to maintain American pre-eminence over China and India. For all its failings, American dominance is better than the alternative. And America is at a disadvantage on this front by having a billion fewer people than the Asian giants. I’m not sure whether this argument should have been in Open Borders: it would take a long time to justify, and open borders appeal to left-libertarian sensibilities that might be offended at the idea of American global hegemony. But it would be an interesting project for the open borders community to look at. How important are marginal increases in population for geopolitical power? Are spurts in population growth followed by increases in various measures of hard or soft power?

In the US, a disproportionate amount of innovation comes from immigrants. More inventors immigrated to the US from 2000 to 2010 than to all other countries combined. Immigrants account for a quarter of total US invention and entrepreneurship. Maybe this is just because America selectively lets smart and innovative people move there. But maybe there are some agglomeration effects going on here specifically related to immigration. Immigration and clustering people together seems to have been key to the success of various intellectual hubs throughout history, like the Bay Area recently, Vienna in the 20th century, and Edinburgh in the 18th century. This is a ripe topic for progress studies to tackle. Aesthetically, I agree with Caplan’s choice not to talk about this much. People talking about all the “amazing contributions” made by a certain immigrant group often comes off as condescending, in much the same way as token engagement with other cultures might.

There are various arguments related to longtermism that Caplan didn’t use. The downsides of immigration (higher crime, perhaps draining the government’s budget) are temporary but the upsides (higher economic growth) bear their fruit over centuries and will likely affect billions of future people. If you buy the argument that what matters most morally is our consequences on the long-run future, this is a point in favour of open borders.

Greying is not something that Caplan discusses much. This might surprise you: a common-sense case for immigration is that people in Europe and America are getting too old to work and they need immigrants to replenish the workforce. There aren’t really jobs that “Americans won’t do”, since, if people don’t like doing something, the wages will rise until they start doing it to meet demand. However, this price is such that there’s significant deadweight loss – mutually beneficial trades that can’t occur. For instance, more people would get more childcare if the government allowed more immigration. Caplan discusses this, but I didn’t feel sufficiently inspired about how great this would be. If I lived in a place with open borders, I’d probably have a personal assistant!

Inequality and selection bias

Caplan is an economist, so I can’t intelligently argue with his reasoning about the economics of immigration. While the book is pretty convincing in arguing that immigration is the best tool we have for reducing absolute poverty, I’m less clear about the effects on relative poverty. Poor Americans still have it great by global standards, but they certainly don’t feel that way, and the point of all this prosperity is presumably to make people subjectively better off. 

Currently, the people who move from poor countries to rich countries are self-selected for being intelligent and conscientious. But what happens when unmotivated unskilled people start coming too? Under the current regime, these people would be relegated to the fringes of society. Does this mean open borders could even make some immigrants worse off, even if their paycheque triples? Checking the strength of the selection bias doesn’t even seem that hard: compare people who were let in randomly or through a competitive process in otherwise similar immigration programs. I’m sure there are papers that look at this that I’m unaware of. 

This is related to the concern over brain drain, which has been massively overblown. Developing countries are not even close to coming up against the ceiling of people who are capable of being in-demand professionals like doctors. Crudely, the reason why there aren’t many engineers in Chad isn’t that Chad trained a bunch of engineers who all left; it’s that Chad doesn’t have many engineers full stop. A lot of the philosophical literature on open borders is confused about this point. Doctors immigrating from developing countries doesn’t reduce the supply of doctors in those countries. The Philippines’ supply of nurses has actually increased as a result of the fact that they send so many nurses abroad. Think about it: If you knew that your only option was to work in a dysfunctional public health system in your home country, would you train to be a doctor? 

Caplan doesn’t consider the extent to which racism and xenophobia might flare up in response to immigration (though he does have a great section covering the effects on social trust). 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. On one level, this is great: Qatar benefits from cheap infrastructure, and the Sri Lankans benefit by getting higher-paid jobs. But I do also fear that this will lead to a racially segregated dystopia.

Immigrant groups might become stratified based on how wealthy they were to begin with. African immigrants would be deeply poor, followed by not-as-poor Indians, then richer Chinese, and so on. What happens to the politics and culture of a society that is so racially stratified? This is of course also a problem now, but I wonder what it would mean to scale it up so much. Statistical discrimination would be rampant, at the very least.

I initially was sympathetic to the view – defended by some philosophers – that wealth inequality is not a problem per se; poverty is. But the more I think about it, the more this feels like squabbles over semantics. Yes, the distribution of resources is not intrinsically morally significant, but the mere fact that poor people don’t have much money isn’t intrinsically morally significant either. Take the literature with a grain of salt, but, holding poverty constant, inequality seems to have lots of negative effects on all sorts of outcomes, including crime. Given that it has negative outcomes, and is frequently caused by unjust social conditions, inequality – which would be increased within countries by open borders – is worth worrying about!

One of the more sophisticated arguments against redistribution is that excessive transfer payments aren’t compatible with high levels of immigration unless you want to go bankrupt, and immigration is better at reducing poverty than government programs. But is this really true? Do places that grow their welfare state subsequently shrink their level of immigration, or shift it toward higher-skilled immigrants? If so, it’s certainly odd that support for immigration and welfare are moderately correlated beliefs. 

The political views of immigrants 

Caplan has a section where he addresses the political effects of immigration, largely drawing on data from Alex Nowrasteh at the Cato Institute. He finds that immigrants are a tiny bit more left-wing than the general population but that their kids and grandkids regress to the political mainstream. This is again a case in which immigrants assimilate more poorly in Europe; it takes more generations for them to be politically indistinguishable from natives. Immigrants and natives didn’t have a partisan difference until the 1980s, and the partisan difference comes from immigrants being more likely to identify as independent, not from being more likely to identify as Democrat. This is interesting but doesn’t address the tail risk of immigration leading to a dysfunctional level of polarisation or backlash. 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.

Here’s Michael Huemer, in one of the most well-known philosophical defences of open borders, on the effects of immigration on culture:

Empirically, it is doubtful whether apprehensions about the demise of American culture are warranted. Around the world, American culture, and Western culture more generally, have shown a robustness that prompts more concern about the ability of other cultures to survive influence from the West than vice versa. For example, Coca-Cola now sells its products in over 200 countries around the world, with the average human being on Earth drinking 4.8 gallons of Coke per year. McDonald’s operates more than 32,000 restaurants in over 100 countries.

This sidesteps the objection. Mass migration to the US is not a concern because Coca-Cola will go out of business; it’s a concern because democracy, freedom of speech, and the rights of women and LGBT people are deeply unpopular in much of the world. Importing millions of people from autocracies and societies that are otherwise deeply illiberal may well have adverse effects on democracy. This makes a good case for having long waiting times for citizenship and voting rights. 

What about the environment?

At no point does Caplan address the environmental harms of open borders. Moving people from low-emitting poor countries to high-emitting rich countries would lead to a pretty dramatic acceleration in global carbon emissions. Admittedly, keeping most of the world poor is a terrible climate change strategy, but there are some climate problems you might want to solve first before advocating for open borders. I’m confident that Caplan has reflected and come to the conclusion that there are no climate problems that we can solve in a short enough time to justify the harm caused by delaying open borders, but he doesn’t show his work. Sometimes, climate change gets used as an excuse for opposing almost any societal progress. This is unfortunate. But “Open borders would create a gigantic problem, namely massively accelerated climate change, but the benefits outweigh the harms” was not the argument I took away from the book. “Open borders are so good, and the objections are not that significant” was the argument I took away from the book.

There are considerations that dampen the environmental objection. Immigration would probably accelerate the trend of urbanisation, and cities are better for the environment (smaller houses, more use of public transport, etc.). A world with open borders would be much richer, and so would have a lot more money to throw at the problem of climate change. People would also be able to move away from the regions that are worst affected. And emissions per capita are going down in most rich countries, while they’re going up in poor ones. 

I’m also concerned about the animal suffering that would result from open borders. Globally, the production of meat, 90% of which comes from factory farms, creates an almost unimaginable level of suffering. There are two reasons why open borders would make this worse: the Western diet is more meat-heavy than diets from other rich parts of the world, and richer people, in general, consume more animal protein. People sometimes talk about the meat-eater problem: many interventions in global development look much less cost-effective if you give moral concern to animals, since, if the interventions save human lives or make people better off, they lead to greater meat consumption. Increased demand for meat may be unusually harmful now, because it further entrenches factory farming as the default way meat is produced.

Shifting the Overton window

Toward the end of the book, Caplan discusses whether it’s a good idea to be advocating for open borders, or whether the idea is so radical that it will turn people off immigration even more. He comes to the conclusion that discussing open borders shifts the Overton window toward increasing immigration. I’m not so sure.

Dominic Cummings has argued that Brexit neutralised immigration as an issue in UK politics because it isn’t so much immigrants that people object to, but the feeling of lack of control. Indeed, immigration to the UK hasn’t radically changed post-Brexit. Some people just feel the government is unrepresentative and dismissive of their concerns about immigration. It’s not like most people even have any idea how common immigration is, nor do they appear to care. Logical debate has not been tried and found wanting. It has been found difficult and left untried. 

This book made me think about what low-hanging fruit might exist in the space of increasing immigration. As mentioned, immigration to many countries is not formally capped but is de facto limited by being confusing and costly. Have people tried to start companies to fill this niche of streamlining immigration? Are there any foundations willing to run this kind of thing as a non-profit? Google turns up surprisingly few results.