Appendix A: What I Left Out

There’s a lot more to talk about with this book, but my main review has all the points I have a strong view about. Caplan discusses the objection that immigrants would lower average IQ, and talks about Garrett Jones’ book Hive Mind, which argues that national IQ is very important in determining national prosperity. I’ll point you to the Slate Star Codex review for more discussion (with the caveat that IQ research is very controversial so please don’t get mad at me).

Caplan has a cute section of the book called ‘All Roads Lead to Open Borders’ in which he describes how open borders remain a good idea under a wide variety of philosophies, including utilitarianism, Kantianism, Christianity, and libertarianism. I don’t have strong views on the philosophy of immigration – my impression studying the subject at university was that any a priori objections should only make a difference at the margin, and are dwarfed by the empirics. Still, there are some plausible moral values you could hold that would make immigration less appealing – such as cultural preservation, or countries’ right to self-determination. Conversely, if you especially value cultural diversity or individuals’ rights to freedom of association, open borders seem more appealing.

One thing I didn’t talk about was brain drain, mostly because I don’t think it’s a very significant problem. Developing countries are not even close to coming up against the ceiling of people who are capable of doing in-demand jobs like being health professionals. 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 also seems to be 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. 

Appendix B: Arguments that Caplan Didn’t Use

• How much of India and China’s economic growth is as a result of the fact that they’re really big, and therefore, moving across them is a lot like immigrating? When Caplan pointed this out, I was pretty surprised I hadn’t thought about it before. Were the two major economies to take drastic steps in reducing poverty in recent decades able to do so largely because they’re really big? This is like one panel on one page, but I felt like he could have developed the argument more. In general, I think the book’s argumentative style leans too highly on Estimates by Economists™ and not enough on case studies and natural experiments. Do more populous countries have greater growth in the long run? If so, this points us in the direction of open borders. Relatedly, I liked how Caplan talked about what Lant Pritchett calls ‘zombie economies’ – economies kept alive by restrictions that forbid people from leaving. A shockingly large share 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.
• There are various arguments related to long-termism that Caplan didn’t use; namely, 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, popular within effective altruism, that what matters most morally is our consequences on the long-run future, this would seem to be a point for open borders.
• Caplan makes it seem like it’s an open-and-shut case that immigration doesn’t lead to an increase in unemployment. But many economists are also fans of the minimum wage. But surely there’s a tension here? If the minimum wage has no disemployment effects, the labour market is perfectly inelastic, and if immigration has no disemployment effects, the labour market is perfectly elastic. So how elastic is the labour market?
• Such 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 disproportionately lets smart and innovative people move there. But maybe there are some agglomeration effects going on here specifically related to immigration? Immigration – or more particularly, 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 20^th century, and Edinburgh in the 18^th century. This seems like 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 [insert immigrant group]” often comes off as condescending, in much the same way as token engagement with other cultures might. Make the case for immigration from prosperity and freedom, or don’t make it at all! But it still has to be confessed that immigrants do seem to contribute a disproportionate amount – technologically, artistically, scientifically, and culturally – to the US.
• I think there are good reasons to believe that way fewer immigrants would actually move than Caplan presupposes. During the entire Greek financial crisis, only 3% of the Greek population moved country (!), at a time when the unemployment rate was 27% – and remember, Greeks have more than a dozen prosperous destination countries to choose from with no paperwork involved! Inertia is the most powerful force in the universe. Caplan’s defence of his high implicit estimates is that, once the ball gets rolling, more and more immigrants from a particular country will move – for instance, 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. Gallup finds 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 people would actually act on this. This makes open borders a little more palatable to people that are sceptical of immigration: it wouldn’t be as different to the status quo as you might expect. 
• What factors have led Canada and Australia to handle immigration so well?
• There is a general perception that Muslim immigration to the EU has gone poorly. How much of this is hysteria? Why would future rounds of immigration not have problems in the same way?
• Greying is not something that Caplan talked about much. At first this might seem surprising – one common-sense case for immigration is that people in Europe and America are getting too old to work and they need immigrants to replenish their 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 no longer 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 to think about how this would be great for me personally. If I lived in a place with open borders, I’d probably hire a personal assistant or something.

Appendix C: One Billion Americans

Another book I read recently and recommend is Matt Ygelsias’ One Billion Americans: The Case for Thinking Bigger (Caplan reviewed it on his blog). He 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. He argues that, for all of 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 this argument should have gone in the book – it would take a long time to justify, and open borders appeals to a lot of 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 the geopolitics of population growth. How important are marginal increases in population to geopolitical power? Are spurts in population growth followed by increases in various measures of hard power? Soft power?