The so-called libertarian case against Brexit works like this. Nations do bad things. E.g., tariffs. And the European Union (“EU”) blocks some (perhaps many of) those bad things. Indeed, the EU has set up a tariff-free free trade zone. That’s a good thing. Therefore EU-good & Brexit-bad. This position is not entirely wrong, but it is only half the story.
First, the EU (and EFTA) free trade zone extends to EU (and EFTA) member states and their dependencies, and also to a few nearby non-member political entities (e.g., San Marino, Andorra, etc). This tariff-free free trade zone does not extend to the world. So when foreign goods are imported into the “tariff-free free trade zone” across the EU’s external borders, EU law mandates a “Common Customs Tariff”. In other words, hand-in-hand with the absence of tariffs among member states is an EU-imposed tariff against non-members’ exports. Whether this situation is a net gain for the people of Europe is a complex empirical question. That question is not answered merely by parroting the EU’s line: we promote tariff-free free trade. No, that question is not so easily answered because although the EU promotes some free trade, it positively discriminates against non-members’ exports.
This is a long and well reasoned post that is worth reading in full. The gist of Seth’s argument is that the political phenomena lumped together as “Brexit” should be evaluated empirically rather than according to someone’s interpretation of libertarian doctrine; there are good reasons for supporters of freedom and open societies to favor Britain’s exit from the EU.
UPDATE: Ilya Somin responds. The reader is invited to evaluate Somin’s full response for himself, but I was struck by this line: “Tillman’s discussion of immigration is notable for its implicit assumption that we can assess immigration policy while completely ignoring the freedom and interests of potential immigrants themselves.” Has there ever been a country that framed its immigration policy in any terms other than its own self-interest?