Bryan Caplan  

Ancestry and Long-Run Growth Reading Club: My AMA Answers

Ancestry and Long-Run Growth R... EconLog Reading Club Round-Up:...
Here are responses to the Reading Club AMA questions, point-by-point:

What about the possibility that the distribution of traits may vary between populations due to genetic differences between populations? If it is those traits are driving long-run growth, and those traits cannot be easily copied due to their partial genetic basis, how does that affect the analysis you've been making in this series and your views on open borders?
The papers covered in the reading club treat ancestry as fixed, but remain agnostic on the mechanism.  It could be genetics; it could just be persistent culture.  The mechanism doesn't really affect their results.  However, my claim that civilized migration outperforms historic migration by swiftly acculturating newcomers does depend on the mechanism.  The greater the role of genes, the less credible my revisionist story becomes.

In general, I am very open to genetic explanations of human behavior; I have a whole book on the topic.  But as I explain in that book, virtually all behavioral genetic evidence measures the effect of genes within the First World.  The fact that environmental differences within the First World have little long-run effect on human development is a flimsy reason to doubt that growing up in the Third World is tremendously damaging.  And as usual with migration, this is not just a humanitarian concern; physical and intellectual stunting also hurts the global poor's potential customers.

While I tend to agree with your assessments, I do have one reservation. Most of these measures are simply looking at the ancestry of the populace, and correlating it with current levels of productivity. But what about institutional impacts? That is, what impact do you think ancestry plays in forming social norms and government policy? Which could then have these observable impacts in productivity.
The papers I discussed present "reduced form results"; they sum all direct and indirect effects of ancestry, institutional impacts included.

For example, if ancestry measures were as predictive as anti-immigration advocates often imply, then we would expect to see homogeneous nations (in terms of ancestry), like Europe, outperform their heterogeneous counterparts: the US. On the whole, I tend to think the opposite is true: heterogeneity outperforms homogeneity.

Indeed, this is just what Putterman and Weil find.

...So I have one final question: given the two options, open borders or open borders given that immigrants from backwards countries (measured by "SAT", IQ, or another relevant measure), and their descendants, are barred from voting, which would you choose?
I would let them vote.  Voting restrictions make sense as long as relatively sensible people care about the well-being of less-sensible people, leading voters to pick policies that are better for everyone.  Contrary to popular belief, this is roughly true for U.S. citizens.  Unfortunately, unselfish voting stops at the nation's border.  A century of U.S. policy shows native-born Americans can't be trusted to treat foreigners with minimal decency, much less take their interests to heart.  Giving foreigners the vote helps them collectively defend themselves from natives' callousness.  While this raises the risk foreigners will treat natives unjustly, the opposite danger is far more serious.

Joshua Woods:

1. What seems to you to be the most promising avenue for future research in this area?

Re-doing all the results with population weighting, so we stop treating China, India, and the United States as empirically relevant as Bhutan, Malta, and Belize.  Nathaniel Bechhofer is pursuing this route already.  You'll know more when I do.

2. The addition of latitude controls drastically affected the coefficients on the various ancestry variables. Do you think this powerful effect of latitude holds today at our much higher technology level?

My best guess is that there's a huge indirect effect.  Latitude mattered a lot directly in the past.  But no matter why a country is poor today, current poverty holds back prosperity in a hundred different ways.

Ben Wilson:

Has any objective research or even informed speculation been done on why latitude effects are so strong? Agriculture concerns would have been important in past centuries, but probably not so much in the past 50 years. Plucky New Englanders might suggest that experiencing the seasons sets our resolve to be more productive (or something).

Easterly and Levine 2003 try to do this.  Their bottom line: "We find evidence that tropics, germs, and crops affect development through institutions. We find no evidence that tropics, germs, and crops affect country incomes directly other than through institutions, nor do we find any effect of policies on development once we control for institutions."  I find their distinction between institutions and policies pretty artificial, but their paper is still the obvious place to start.

COMMENTS (4 to date)
Decemberist writes:

Thanks very much for responding to my question Bryan. I agree with you that the argument for civilized migration becomes weaker if genes play a more prominent role in outcomes between populations. While I agree with you that the differences in environment between the third world and first world *may* be more important than any genetic differences between the populations, there is at least some very suggestive counter weighing evidence that the genetic differences may actually play a larger role than we thought.

The primary evidence for this is the differing average outcomes of populations within first world countries and second world countries. For instance, ethnic Chinese in countries other than China in which they are a minority populations tend to have average or higher than average salaries compared to the host country in almost all countries, while the reverse is true for people of African descent in countries outside of Africa. Perhaps that is due to self-selection or globalized systemtic barriers of some sort, but taken together with what we know about the genetic component of certain traits such as (here it comes) g/IQ, and the correlation of traits like g/IQ to, among other things, income, it's plausible that part of the difference in outcome between groups may be due to genetic difference between groups. If so, their ability to adapt to various expectations may be impacted.

That does not in any way means a country should ever bar an entire population from immigrating, but it does suggest that it may have to be *selective* about which people get in, in order to harness the full fruits of productive immigration.

Joshua Woods writes:

Thanks for answering my questions, Bryan. I do support open borders but it's the Huemerian style of ethical intuitions (as presented by you) which really swayed me into thinking that way. The economics of the issue appears to be extremely complex, yet clearly not catastrophic enough to overcome the general presumption against preventing hiring/renting to migrants.

Denver writes:

Thanks for answering.

I guess I worded my first question poorly. I understand that the ancestry adjusted measures account for all effects, direct and indirect. I was more so asking about the absence of an effect. That is, how much do you think the divergence shown in Putterman and Weil's data (USA, Canada, Singapore, etc) is due to the insulation of ancestral effects on institutions? That's why I gave my example: while the US is ancestrally heterogeneous, it's arguable that it's institutions are not.

E. Harding writes:

"A century of U.S. policy shows native-born Americans can't be trusted to treat foreigners with minimal decency, much less take their interests to heart. Giving foreigners the vote helps them collectively defend themselves from natives' callousness. While this raises the risk foreigners will treat natives unjustly, the opposite danger is far more serious."

-Not a single word of this is true.

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