Bryan Caplan  

Open Borders and Global IQ Bleg

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Another bleg from the tireless Vipul Naik of Open Borders.  Vipul's words:

What impact would open borders have on global IQ within a generation or two?

Even hardcore IQ hereditarians concede some sort of Flynn effect and the role of malnutrition in depressing African, and possibly Indian, IQ. Open borders would correct this, and raise global IQ, IMO.

If the answer is that global IQ would rise, would the compositional/distributional effects of low IQ immigration to the developed world be so bad as to make open borders a net global harm from the innovation/economic prosperity perspective?

Restrictionists, including BK in Open Borders comments and others on EconLog (quoted at ) have argued that the desegregation effects (with more low IQ people entering the countries that would pursue technological frontier innovation) will be a net minus for global innovation, economic prosperity etc. despite the rise in global IQ, due to mechanisms like crime, political externalities.

I am interested in a universalist analysis rather than a citizenist/nationalist analysis, i.e., what would be the benefits and costs for humanity as a whole.

Please show your work.

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COMMENTS (17 to date)
Steve Z writes:
Even hardcore IQ hereditarians concede some sort of Flynn effect and the role of malnutrition in depressing African, and possibly Indian, IQ. Open borders would correct this, and raise global IQ, IMO.

I'm a Flynn-effect skeptic, and it seems extravagant to have to import people to improve their micronutrition, so I think the effects would be small relative to costs. Moreover, even if you're a Flynn-effect believer, the cause proposed by Flynn for the Flynn effect is that culture is more intellectually stimulating today. But if we import a bunch of lower-IQ people, then culture will get less stimulating. No more Flynn effect -- meaning that the effort is self-defeating.

Nathan Smith writes:

The thing to remember is that several studies have found huge benefits to global GDP from open borders. The modal estimate seems to be that open borders would double world GDP. Note that this involves some conservative assumptions. If you just assumed that TFP stays the same in each country and everyone moves where they're most productive, you'd get a lot more, I'd guess world GDP multiplies 4-5 times or something like that. If you want to postulate a causal chain...

lower average IQ in rich countries => worse institutions => lower world GDP

... the institutional deterioration has to be pretty strong to overcome the prima facie gains from people moving from low-productivity places to high-productivity places. Steve Z's comment seems not to understand this. If open borders has no effect on global average IQ, but lower-IQ immigrants don't reduce productivity in host countries via an institutional channel, or don't reduce it much, you still get huge gains from open borders. Only if there's a BIG deterioration in institutions can this effect be canceled out.

In the comments of this recent post at Open Borders, BK did some impressive back-of-the-envelope calculations suggesting that world GDP might be increased if more-productive minorities in a few countries, e.g., Malaysia, the Caribbean, South Africa, could be somehow segregated from the less-productive majorities they live among. This result took me by surprise, and I can't deny a certain numerical plausibility.

But my strong bias would be that IQ=>institutional quality is far too simple a story, and that history and founder effects have a much more important effect. Thus, if you compare Malaysia, where the Chinese minority are comparative newcomers, or South Africa, where the white minority have largely played the role of invaders and oppressors, to a United States which adopted an open borders policy, say in 2012, it seems highly unlikely that immigrants would feel, and vote according to, the kind of solidarity-of-the-poor-majority that we see in those countries. A comparison with 19th-century America seems more likely to predict the outcome; or perhaps a mix of both. There may have been *some* institutional deterioration in the 19th-century US as a result of immigration: I recall from my AP US history class the "machine politics," e.g., Tammany Hall, which emerged in big cities in the late 19th century, with corrupt political bosses drumming up votes with handouts to immigrants. But it didn't prevent dazzlingly impressive growth. So I'd expect moderate institutional deterioration at the worst (and it wouldn't surprise me if voting-with-the-feet effects and newcomers' heightened appreciation of freedom and diminished support for the welfare state and other factors actually improved institutional quality under open borders). Moderate institutional deterioration wouldn't come close to offsetting the growth on GDP.

And this is with a rather pure form of open borders in which immigrants can get the right to vote fairly quickly and easily. But there's no need to do it that way. BK, who launched this debate, seems to favor "keyhole solutions" rather than closed borders. For example, he seems to endorse the "don't restrict immigration, tax it" policy which I advocated in Principles of a Free Society. It shouldn't be too hard to design policies that keep wealth-fostering institutions intact (or improve them) while allowing a lot more people to come and benefit from them.

Nathan Smith writes:

Since this bleg is about the economic frontier as well as open borders, I wanted to draw attention to my own research, a major goal of which is to understand what pushes the frontier forward. My big idea is Adam Smith's big idea: productivity growth depends heavily on specialization, trade, and the division of labor. Neoclassical equilibrium economics tends to neglect this factor, because it is pervaded with the assumption of perfect competition, which in turn requires the assumption of "infinitely" large numbers of buyers and sellers in every market, which only makes sense if the gains from specialization and trade have been exhausted. In defense of this assumption, it is often claimed that if they had *not* been exhausted, there would be monopolies in every industry/job specialization. But this argument does not succeed, because there are good reasons not to pursue specialization to the point where one becomes depends on monopolists or monopsonists on every side. Competitive markets serve a useful institutional function, preventing hold-up and coordination problems and limiting the vulnerability of systems to "weak link" disruption, and people under-specialize to keep markets competitive. You can see this all over the place once you know how to look for it.

I think that specialization and trade is the main reason why institutions matter. Allocating resources and incentivizing effort are less important than enabling complex networks of specialization and trade. The corporate form of business organization is a good example of this, separating management and control, and relying on multiple external markets-- the stock market/market for corporate control, the market for managerial talent, as well as labor markets, product markets, markets for capital goods, etc.-- to discipline it, as it coordinates the activities of thousands, tens of thousands, hundreds of thousands, occasionally millions (Wal-Mart) of its own employees, and relies on and/or directs many others external to itself (e.g., upstream or downstream in the supply chain). This requires all kinds of accountability, legal infrastructure, etc.

Specialization and trade also affect how the technology frontier moves forward. Suppose a genius inventor is stranded on a desert islands, and in his now-abundant spare time, he figures out how to make a home-delivery system for ordinary retail goods using flying drones which will be 50 times more efficient than traditional shopping. Useless. He can't implement it. New ideas like that can only be implemented in the context of a large economy. Note that the limiting factor is NOT idea creation in this case: he's got the idea all figured out. But a desert island is too small a scale. A city is probably too small a scale to cover the many kinds of fixed costs involved in implementation. It might take a big national economy to make the idea work.

Specialization is related to segregation. Specialization often means like people seeking like people to work with, to get feedback from, to do the parts of the already-specialized job that you don't do best. A forced desegregation where we were all randomly mixed up and then forced to work mainly with our neighbors would devastate productivity. But markets are always sorting, sorting, sorting people. Charles Murray and others have noticed that Americans have been segregating themselves, "coming apart," in recent decades, and it's probably made us more productive. But note that IT DIDN'T REQUIRE COERCION. You don't have to draw borders and enforce them so that the productive people can segregate themselves and become more productive. Just get out of the way.

I think in a global economy with open borders we'd see a lot more sorting. We'd see people sorting themselves across national lines, moving not just to the place within a country where they're most productive, but to the place in the world where they'd be most productive. It's like with trade. Empirical studies tend to show that openness and international trade yield growth gains far greater than neoclassical comparative advantage would predict. Why? Because they allow new, more productive patterns of specialization and trade to develop. Open borders would have the same effect, allowing firms to seek the best people from all over the world. Yes, there are some political risks, but even a sudden jump to pure open borders probably wouldn't "kill the goose" to such an extent that the growth gains from open borders would be erased, and careful policy design can make the political risks almost negligible compared to open borders' upside.

Hugh writes:

What impact would open borders have on global IQ within a generation or two?

I don't think that our knowledge of IQ is sufficient to answer this question.

I would imagine that a program to ensure the availability of iodized salt in poorer countries might have a bigger effect.

Likewise, economic advances in poorer countries might trigger a positive feedback effect whereby increased wealth allows better nutrition which increase IQ which, in turn, increases wealth -thereby completing the loop.

Sorry, but I'm not a big believer in Open Borders.

Steve Z writes:

I have devised two thought experiments that will hopefully illumine the extent of the disagreements here.

First, imagine that you get a call on a red telephone. A voice on the other end tells you truthfully (and you know and believe it's true), that there is an alien planet with close to the same number of life forms &c as on our planet. It's in another galaxy; we could never run into them; their ways are strange to us, but they are conscious, they suffer, and they love (and hate) one another, the same as we do do. The one difference is that there are slightly more of them (by epsilon), and so one can infer they suffer/love/hate/etc. a little more than we do. The voice on the red telephone relates that very soon, they will press a button that will transfer our material resources to their planet, leading all of humanity to die in the dead of space. There is no way to contact them or persuade them not to do this. The voice then states truthfully that there is no way to stop this, except by pushing a red button which will kill them all instantly. Would you push it? From a universalist utilitarian perspective, the case is overwhelming that you should.

One can alter this scenario so that they are only reducing our standard of material comfort &c, but it's hard for me to find a philosophical justification for coming to a different answer in those cases. A consistent utilitarianism shouldn't turn on qualitative questions of degree.

Second, picture the same scenario except that, instead of an alien race, the Others described by the voice are humans, who exist in a parallel world. None of them are the same as present humans, so you have no filial bonds in common. Once more, there's, say, one more baby on that planet than ours, so they have a slightly better utilitarian claim to survival. Do you press the button?


Bryan Caplan and Vipul Naik seem to be committed to pressing the button in both cases. But I could be wrong.

Jeff writes:

The effects on IQ of unfettered immigration are as follows, as my best guess: better nutrition and health outcomes marginally improve the IQ of Africans, Hispanics, Indians, etc. However, this is offset by the fact that the influx of low IQ immigrants drives up real estate prices in desirable neighborhoods with good schools, because the natives don't want to subject themselves or their children to the political externalities caused by concentrations of low IQ immigrants, namely crime and political corruption. Higher real estate prices encourage smaller family sizes, at least for middle and lower middle class couples (the upper classes being largely unaffected), lowering the total fertility rate of middle IQ people.

The low IQ immigrants have higher fertility rates than native peoples (sometimes much higher), but this settles closer to the national average over a generation or two as the immigrants assimilate, but still the end result is that the bell curve shifts to the left over successive generations.

Sorry, I can't really cite any data, but that's my suspicion.

Eric Falkenstein writes:

If simply pulling in poor (and low IQ) people into US institutions raises their productivity tremendously without hurting the domestics, why don't we simply do the less drastic thing of exporting these better institutions, or bringing in more productive firms? That seems easier as a hypothetical, but we know this is hard. As economists are befuddled by Haiti's poverty, I think it's wise to assume we don't understand how adding a lot of Haitians to America would work out.

tom writes:

The largest, and most common, mistake that I have seen made in anti-immigration arguments is assuming, implicitly or explicitly, that immigrants are an average representation of their former populations and this is almost certainly bogus because immigration is heavily self selecting.

1. Emigration requires savings. Simply traveling to a port to catch a slow moving vessel (the cheapest option for basically all African countries) is of significant expense of people making a few dollars per day. This isn't a "decide to emigrate, save for a week, leave" scenario.The first waves of immigrants will be people who have already saved or people selected by their own extended families. If you can't save enough individually your family has to pool money. Who gets to go? If you are sinking the majority of your savings you aren't sending the black sheep of the family to a foreign land and hopes he makes good. You send the conscientious one- someone who can hold down a job and the one most likely to send money back home to help bring other family members over or simply to help them out/repay his debt to them.

2. You don't send criminals, but criminals also don't want to go. If you make your mark with violence and fear your reputation, which stays behind, is an asset while you move from a low law enforcement area to a high law enforcement area. That is not a winning proposition.

3. You also don't send the elderly, nope you send the young. Those who have the longest to produce at the higher level and will also assimilate faster to the new environment. This blows up most of the arguments that immigrants will destroy the current institutions as young people don't vote heavily and are more likely to be open to the new ideas and adapt to the new culture.

4. The poorer a country the fewer immigrants it will be able to send. Immigration will be heavily weighted towards countries that are 1-2 rungs below their future country, as they will have more resources to invest and have fewer barriers when they arrive. They are also more likely to have relatives from their area who have already emigrated living in their target country. The image of tens of millions of HIV infected Africans showing up on day one is extraordinarily unlikely.

The average immigrant in this scenario is going to be of higher than average intelligence, reliability, honesty and are younger than average, and they will be from areas that are more likely to be similar to their destination. Heavy self selecting rules out basically all of the objections to open boarders with the only exception being individuals who move to take advantage of welfare programs, which is easily handled by not making them eligible immediately.

Matt writes:


I think your premis is wrong. You assume: An Open borders policy is sustainable. In trying to imagine how a scenario in which all borders magically open tomorrow would play out I can't believe that the situation could sustain itself. The problem is the negative externalities happen affect those in rich countries in the short run, the more positive effects will take much longer to become apparent.

So I imagine 2 possibilities , those used to living with good institutions quickly act to prevent their deterioration, or they abandon them and move someplace and take their high social capital with them. Either way they close up shop.

Consider the population of city like NY doubling overnight. Where would people stay? Could the city continue to maintain order? Would revenue grow enough to promise the same level of services for current residents, or would services have to be drastically cut, with higher overall spending plus lower per-capita spending? Solve for equilibrium..

Now imagine NYC doubled in size in the next 25 years, how different an experience would that be?

A few years ago Tyler, who seems to agree with you, had a post arguing for creating Favellas outside of major american cities to support open immigration policies. Would you live next to the favella? Do think the favella would be safer or less safe than your current neighborhood? Do you think you should how much more in taxes are you willing to pay to police the favella? What about when hungry favella residents come to your neighborhood, would you find it comforting?

Tom writes:


Why in the world would 20 million people show up to NY without a job waiting for them or a place to stay? This isn't a situation where massive crop destruction is driving hoards of rural dwellers into the cities desperate for food. Some people might show up without options but the odds of an over whelming flood of immigrants happening overnight are somewhere between zero and a number indistinguishable from zero.

Mr. Econotarian writes:

We should also keep in mind that many countries have IQ's reduced due to parasites, most of which exist only in tropical areas. Bring them farther north, and those parasites can't survive. Malaria is a major factor.

Regarding Matt's concern about NYC doubling in population, such a doubling occurred from:

1790 to 1800,
1800 to 1820,
1820 to 1830,
1830 to 1850,
1850 to 1870,
1880 to 1900,
1900 to 1930.

Favellas are a side effect of lack of secure property rights. They would not be possible in the US.

There are 1.6 million vacant houses in the US (as of 2Q2012), many built during the bubble and just sitting there waiting to have paying inhabitants.

Matt writes:


I know how often NYC doubled its population. However, NY was much poorer then and had much more open space. Since there were very few city services, they couldn't really be disrupted. I am not arguing the long term consequences are negative, but that the short term ones are, and back then other than labor competition the short term consequences were fine.

Also Many of those time periods are 20 or 30 years, a time frame I explicitly call acceptable.

So if 8 million people show up in NY tomorrow, where will they stay? A whole lot of them will end up in central park, lets see the police move 250k people out of the park, then to where? Property rights are only secure if you can enforce them. Will Doubling the population in a day make property rights more or less secure?

In 1935-36 200k okies showed up in california. It took years before they were no longer living in camps (favellas) outside major cities. The reasons favellas stick around hasn't to do with property rights it has to do with the continuing presence of new poor people moving from the country side, or this case from another country. Until populations stabilize between rich and poor nations expect permanent favellas.

Ghost of Christmas Past writes:

If by "global IQ" you intend something like "the arithmetic mean of IQ's of all living people a few years after a mass migration," then I think open borders would likely lower "global IQ."

The devil is in the denominator. On average, when people move from poorer to richer countries, their fertility increases (the typical Malthusian response to greater resource availability). Consider the example of Mahamadou Tounkara, who may stand for millions. Their descendants may assimilate toward the lower fertility rates of the (formerly) rich country, but even so, one side effect of migration is a higher absolute population (basically forever, unless TFR falls below replacement).

Worldwide, low-IQ people outnumber high-IQ people and low-IQ people are more likely to be found in poor countries. Migration from poor countries to rich ones would probably increase the fertility of low-IQ people more than high-IQ people. (Partly because of migration-fertility effects, partly by increasing competition for housing in (formerly) rich countries and thereby depressing fertility of non-migrants in those countries.)

(It is conceivable, though I have no data on this point, that the fertility of non-migrants in poor countries might go up if any significant number of their former neighbors migrated to rich countries, because of reduced comptetition for land in the poor countries and wealth effects from remittances or sentimental FDI attributable to migrants. That would add even more low-IQ people to the "global IQ" mean.)

Anyway, if you increase the number of low-IQ people faster than the number of high-IQ people (which is the most likely effect of open borders, at least for many decades), you are bound to drive down the arithmetic mean of all their IQ's.

The Flynn effect is irrelevant. Not only does the Flynn effect bypass g which is the real quality of interest, the Flynn effect doesn't boost IQ scores, just "raw" scores on subsegments of IQ tests before "norming." Since the Flynn effect doesn't change IQ scores, it cannot change the arithmetic mean of IQ scores.

As for alleviating malnutrition, that would be a good thing and could hypothetically boost "global IQ," though I doubt by very much. It is sad but true that the better you equalize environmental factors, the more genetic ones dominate. Feeding malnourished low-IQ people better (whether you feed them better in their old homes or in new ones) could narrow the IQ distribution and even raise the mean, but cannot raise the mean for any cohort above its genetic maximum mean. Since the genetic maximum means for the lowest-IQ cohorts (mostly groups of sub-Saharan Africans) are well below the current global mean and those cohorts are relatively small compared to global population, I doubt nutritional interventions would boost the global mean very much-- certainly not above the means for current "rich" countries.

Someone will point out that for any reasonable assumptions about IQ distribution(s), increasing world population would increase the absolute number of living geniuses (it would also increase the absolute number of imbeciles). So the next question might be: are those geniuses worth the cost? We could increase the number of geniuses (say 4-sigma IQ) much more cheaply by subsidizing the fertility of, e.g., Hungarian Jews (geniuses maybe 1/1.6e4), than by boosting the fertility of sub-Saharan Africans (geniuses perhaps 1/1.7e6).

BK writes:

Jeff's point about the fertility rate of natives is interesting. But Chinese fertility has been plummeting in both Malaysia and Singapore (Malaysia falling towards Singapore low rate):

THE growth of the Chinese population in Malaysia has been decreasing for several decades. While the number of Chinese Malaysians increased from a mere 694,970 in 1911 to 6.39 million in 2010, their proportion of the population decreased, from 35.6 per cent in 1970 to 24.6 per cent today.
The main cause is a decreasing fertility rate: in 2000, the crude birth rate among the Chinese was 20 births per thousand people, but it dropped to 12.5 by 2009.

According to latest 2010 statistics, Singapore’s resident total fertility rate (TFR) reached a level of 1.1 in 2010. The Chinese TFR was (1.08), followed by Indians (1.14) and Malays (1.82).

Birth rate 9.34 births/1,000 population (including all groups)

Guest worker nannies do not seem to have boosted Singaporean birth rates much.

However, this does point to the global phenomenon where the groups that have historically performed worst economically in rich countries, have the lowest IQ, etc, are increasing in population more rapidly. In the U.S. there is downward pressure on average school performance from demographic shifts, even as test scores have been slightly improving for each demographic group. Within the U.S., as globally, there are big differences in age of childbirth and total fertility that affect population growth.

These effects mean that a) we should expect the mixture of migrants under open borders going forward to become somewhat worse over time with respect to history of economic productivity; b) lower-performing migrant populations are more likely to become an electoral majority, and sooner, than one might otherwise think.

Steve Sailer writes:

Vipul Naik could do wonders for his subcontinent's average IQ by donating to or volunteering for Kiwanis International, which does outstanding work battling cretinism around the world via micronutrient supplementation.

Vipul Naik writes:

Steve Sailer, thanks for the pointer. A while back, I think shortly after reading about the micronutrient-IQ causal linkage, I had done a preliminary investigation of philanthropic opportunities in this area. As many of us do, I turned to charity evaluator GiveWell. Although GiveWell found micronutrient supplementation potentially promising, they weren't able to find any giving opportunities in the area (see here, for instance). Among the charities that GiveWell did consider were Micronutrient Initiative and Vitamin Angels. GiveWell's assessment seems to largely match my impression.

GiveWell has not evaluated Kiwanis, and a quick eyeballing of the website and Wikipedia page does not suggest to me that volunteering with them would do "wonders" for Indian IQ or, for that matter, the IQ of any country. Micronutrition does not seem to be much of a focus for Kiwanis, for one thing. If further investigation reveals Kiwanis to be more promising, I will suggest to GiveWell to evaluate Kiwanis.

Thanks once again for the suggestion.

PS: A charity operating in India, my country of citizenship, does not make it more worthy of consideration than a charity operating elsewhere in the world. In fact, a significant fraction of my charitable donations have been to a charity operating in Africa.

PS2: Your (Steve Sailer's) concern for the welfare of people in far-off lands, as evidenced in this comment, defies the caricature of citizenists as people who care solely for their current fellow citizens. Mea culpa, if, through thought, word, or deed, I lent credence to that caricature.

Cryptomys writes:

Personally, I believe the Flynn effect is caused by the viral spread of memes.

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