Ancestry and Long-Run Growth Reading Club: Concluding Thoughts By Bryan Caplan

Garett Jones inspired my intellectual journey through the literature on ancestry and long-run growth. When we debated last semester, I initially expected him to base his case on the economic importance of average national IQ. He alerted me upfront, however, that he had other plans. Instead of hailing the power of IQ, he heavily relied on the power of ancestral “SAT scores” – state history (S), agriculture (A), and technology (T). I read the key papers before the debate, and revisited them for the reading club. What’s my takeaway?

1. If you want to understand why some countries are rich and others are poor, ancestry research is a major advance. Like it or not, countries inhabited by the descendants of relatively economically successful societies tend to remain relatively economically successful today. Transplanting advanced civilizations has proven easier than transforming backwards civilizations.

2. Still, ancestry research has weighty shortcomings. Overall, Europeans have been far more successful than their ancestry predicts. Their SAT scores are mediocre, but European civilization has economically conquered the globe. Ancestry scores don’t explain the leading role of the United States, or the lingering poverty of China and India. And you can’t credibly dismiss the three most populous countries on Earth as irrelevant “outliers.” Any theory that badly fits China, India, and the U.S. has serious problems.

3. In 1950, Asia and Africa were both desperately poor. An ahistorical thinker would therefore expect the two regions to remain in their unfortunate situation. An historical thinker, knowing the two regions’ radically different SAT scores, would make a rather different prediction: Asia will regain its former glory, but Africa will stay poor because it has little former glory to regain. Both historically-informed stories have proven strikingly accurate.

4. But: In 1950, an historical thinker would also have predicted the economic resurgence of the Middle East, the cradle of civilization. Oil aside, this didn’t remotely happen. For the Middle East, it’s the ahistorical thinker who wins, hands down. Given the antiquity of Middle Eastern civilizations and the size of the region, this is a deep failing for ancestry research.

5. As far as I know, Garett is the only thinker who openly uses ancestry research to justify immigration restrictions. It’s not clear any of the authors of the papers we covered draw any connection at all. But on the surface, it’s the natural interpretation of their results – especially if, like most humans, you’re a nationalist at heart. If I were Garett, I wouldn’t be swayed by the original researchers’ reticence. Hyper-cautiously refusing to explore the broader implications of your research is a classic academic failure – especially if the broader implications offend left-wing sensibilities.

6. Garett is nevertheless deeply mistaken to base his case against low-skilled immigration on ancestry research. Basic fact: The people of the United States are below the world average for both state and agricultural history. The people of Europe are better, but not by that much. As a result, the regressions Garett emphasizes literally predict that open borders will be even more productive than its fans previously calculated.

7. An added problem: ancestry research treats all migration as equivalent. It doesn’t matter how national ancestry changes as long as it does. On the surface, though, it’s hard to believe that conquest, genocide, transportation of slaves, differential fertility, and what I call “civilized migration” have equivalent long-run cultural effects, holding ancestry constant. When people voluntarily move from backwards to advanced countries to peacefully create new lives for themselves, they typically leap to a new and better equilibrium. The immigrants largely escape the dysfunctional hand of the countries of origin; their children escape it almost entirely.

Garett may call this wishful thinking, but these are hard, happy facts most of have directly experienced – or lived. My wife, for example, migrated from Romania to the United States when she was 7. Culturally, this made her 95% American, and our children 99.5% American. I’ve see the same transformation in virtually every immigrant family I’ve ever known – including many hundreds of immigrant students I’ve taught at GMU. Insisting that their ancestry remains a worrying concern frankly seems silly – even though I expect their home countries to continue on their generally disappointing ancestral trajectories.



8. But what about what Garett calls the “Open Borders Sacrifice” – the possibility that open borders will impoverish your descendants while enriching mankind? For starters, the moral subtext is absurd. Ending state-imposed discrimination against blacks wasn’t a “sacrifice” for U.S. whites; it was minimal decency. The same goes for ending state-imposed discrimination against foreigners. Even a moral relativist should appreciate the parallel.

9. Moral subtext aside, though, are Garett’s fears credible? Distribution is tricky, but if you buy the ballpark prediction that open borders will double global GDP, it’s nearly impossible to believe any sizable group will lose on net. Oil consumers may gain more than 100% of the benefit of increased oil production, but that hinges on highly inelastic supply and demand for oil. When migration dramatically increases global production virtually across the board, there is every reason to think the benefits will be broadly shared. Unconvinced? When was the last time a sharp rise in global production made the average American poorer? Non-economists may point to the rise of China, but they’ll struggle to find an economist who backs them up.

10.Now that I’ve finished my intellectual journey through ancestry research, one thing deeply puzzles me: Why did Garett appeal to the power of ancestry, instead of focusing on his own research on national IQ? Convincing people ancient history matters is an uphill battle. And since the ancient history of Americans’ ancestors is nothing special, it’s a red herring anyway. It would have made a lot more sense for Garett to focus on intelligence, where people of European stock are near the top – a smidge below Eastern Asians – and the people of Latin America, India, Africa, and almost the whole Muslim world do very poorly. Why he didn’t take this route to immigration restriction is a great mystery to me. In a few months, perhaps I’ll try to solve it.