Bryan Caplan has a post that discusses a hypothetical eugenic regime:

Imagine a Eugenic America where citizens who earn less than median income are forbidden to have children. Enforcement isn’t perfect, so 5% of all kids born are “illegals.” Over time, this leads to a substantial stock of people who weren’t supposed to be born in the first place.

Pundits have the predictable range of positions on eugenic policy. Liberals demand amnesty for the current stock of illegals, and pledge stricter enforcement of eugenics in the future. Conservatives oppose amnesty – partly because they don’t want to reward law-breaking, and partly because they don’t trust liberals to help them strictly enforce eugenics laws. “Think-outside-the-box” thinkers occasionally chime in, “Fertility policy should be skill-based! Letting talented low-income people breed is good for America.”

As this morally blind debate rages on, a libertarian arrives on the scene. He vocally proposes “Open Breeding.” Abolish eugenics laws, and let any woman who wants a baby have a baby. Mainstream reactions are diverse, but uniformly negative.

Some commenters objected that birth restrictions are very different from immigration restrictions. If I wanted to get cute I’d point out that Bryan never claimed the two cases were similar, indeed he never mentioned immigration in the post. It was the commenters who drew that analogy. I wonder why?

Now of course Bryan probably did think this was an interesting analogy to the immigration debate. And commenters are quite correct that it’s possible to argue for immigration restrictions and against birth restrictions. The two cases are not identical. But I think that misses the more interesting point. As I read Caplan, he’s not really making a good argument for open borders; he’s making a good argument that “we” should not trust our opinions on the open border question. By “we” I mean the 99.9% of people who have a sort of visceral negative reaction to the idea of unlimited immigration.

One can certainly imagine a society where respectable opinion believed in eugenics. Indeed in some respects that society existed 100 years ago (although actual policies were milder than in Bryan’s example.) While Bryan’s analogy didn’t convince me that open borders are a good idea he did change my Bayesian prior on the issue. That’s because I now realize that my gut instincts are not reliable. He’s completely right that respectable opinion in a eugenic regime would have scoffed at Caplanesque arguments for a 100% open birth policy. That doesn’t mean he’s right on immigration (or indeed even eugenics), but it does suggest we should be skeptical of claims that open border proponents are somehow “loony,” merely because most respectable opinion recoils from the notion of open borders. Bryan showed why respectable opinion would not be reliable in an area where many of the very same “gut instincts” come into play (such as the fear of “our civilized society being overwhelmed by barbaric hoards.” My words not Bryan’s.)

BTW, there is one country that does view children born in violation of government regulations as “illegals.”

IN HER parents’ bare brick-built shack in southern Beijing, Li Xue sifts through piles of court verdicts, petitions and other papers that record her family’s struggle for most of the 20 years of her life to secure a simple document: a household registration certificate, the basic building block of official identity in China. Because she was born in violation of China’s one-child-per-couple policy, local officials will not give her one. As a result she could not go to school. She now cannot get a job, nor get married, nor even buy a train or plane ticket. Despite recent moves to relax family-planning rules, the ordeal for Ms Li (pictured) is still far from over.

Read the whole thing. I’ve actually met academics that favor China’s one child policy. I’m pretty sure they’d be horrified by this story. They’d say it’s unfair to punish the innocent child for the sins of their parents. But is it really possible to have a clean, antiseptic one child policy that doesn’t punish the children?

Suppose that the Chinese government had instead relied solely on a monetary fine imposed on the parent who violated the one child policy. How do you enforce that? Most peasants are too poor to pay a substantial fine. Yes, you could take away all their wealth and push them into abject poverty. But in that case you’d still be punishing the child. They would not eat well. The parents could not give them medical care; they could not afford to send them to school.

Now ask yourself how many of those academics that supported the one child policy actually thought through what would happen to the millions of children born in violation to that policy? I’d guess not very many. Now let’s consider immigration restrictions. Is there a clean, antiseptic way to keep out illegal immigrants?

Bryan has not convinced me that 100% open borders are clearly the way to go. But he has convinced me that my objections to his arguments are not as reliable as I might have assumed. My reservations about open borders are actually pretty similar to the reservations that people in a eugenics society would have had to a proposal for an open birth policy.

Yes, the two cases might be different enough that the analogy doesn’t hold. Maybe open births are good and open borders are bad. But the fact that superficially similar arguments against birth restrictions would have been rejected out of hand by a eugenic culture should, at the very least, make us do a bit of soul-searching.

Let’s face it, most people oppose open borders at the gut level, and then they search for logical reasons to support the position that had already formed in their reptilian brain. It’s all about the prospect of Kolkata on the Hudson, or Kinshasa on the Hudson. I consider myself to be less xenophobic than the average person, but even I recoil slightly at the prospect of the messy third world moving en masse to the United States, so I can understand that fear. But Bryan keeps showing us that our gut instincts on immigration might well be wrong.

Thought experiment: Suppose that in an alternative world eugenics was adopted in the year 1000. By the year 2014 the average IQ in the world was about 115 (using our current scale of 100 being average in our world.) Also suppose that there was no abject poverty, and no war. And suppose I presented a paper saying that society made a mistake in the year 1000, that eugenics should not have been adopted. A professor objects that my alternative scenario would have led to a world with billions of people with IQs in the 70s, 80s and 90s, instead of less than one billion. An alternative world with war and genocide and billions living in abject poverty. A murder rate 5 times higher. For every 10 Einsteins, there would only be one. How would I respond to that professor?

My point is not that eugenics would have been the right way to go in the year 1000. I don’t believe that. Rather it is that when something has become the well-established status quo, it’s really, really hard to argue for something radically different. Even if you are right.