Long-Term Barriers to Growth

By Enrico Spolaore, Professor of Economics and Chair of the Economics Department at Tufts University, and Romain Wacziarg, Professor of Economics, Anderson School of Management, UCLA; and Research Fellow, CEPR. Originally published at VoxEU.

There is now widespread agreement that ‘deep’ history matters for comparative development. Recent research has shown that ancestry – the transmission of genetic and cultural traits across generations – matters more than the history of geographic regions. This column argues that long-term divergences in inherited traits can create barriers to the diffusion of technology. The greater a population’s genetic distance to the population on the technological frontier, the lower its relative income will be. Development policies should aim at reducing barriers to exchange and communication.

Students of comparative development have turned their focus to factors rooted deeper and deeper in history.

  • There is growing agreement that human and geographic factors inherited from eras as far removed as the Neolithic period still influence the wealth of nations today.
  • An early example of this hypothesis was Jared Diamond’s book Guns, Germs and Steel (1997), where he argued that geographic advantages from early human history still affect prosperity today.

Economists no longer focus exclusively on the proximate determinants of growth, such as capital accumulation or technology – they now study deeper causes rooted in long-term history. The debate today is not whether deep history matters, but why and through which mechanisms it operates to affect current outcomes.

Ancestors matter, but why?

An important insight from the recent empirical literature is that the history of populations is a much stronger predictor of current economic outcomes than the history of geographical locations. For example:

  • A long familiarity with organised modes of government and a long exposure to agriculture are good for economic development. But it is the history of a population that matters – more than the population’s location. The US is rich today because of the historical heritage of its European colonisers.

The deep history of North America matters much less (Putterman and Weil 2010; Comin, Easterly and Gong 2010).

  • The reversal of fortune – documented by Acemoglu, Johnson and Robinson (2002) at the level of geographic locations for former colonies – disappears when correcting for ancestry and expanding the sample beyond former colonies (Spolaore and Wacziarg 2013a; Chanda, Cook and Putterman 2013).

This once more suggests that development can be accounted for by factors that are transmitted from generation to generation.

  • A closely related literature argues that geography and biology affect current development because of long-term indirect effects, transmitted from one generation to the next, and going back to prehistoric times (Diamond 1997; Olsson and Hibbs 2005; Ashraf and Galor 2011, 2013).

Even though Jared Diamond’s well-known book Guns, Germs and Steel is often presented as a purely ‘geographic’ interpretation of comparative development, at its core is the historical transmission of biogeographic advantage – such as agricultural knowledge and resistance to germs – across generations. According to Diamond, early inhabitants of Eurasia passed those advantages on to their descendants, who then moved to dominate large parts of the rest of the world.

In sum, a central message of the recent research on comparative economic development is that history matters because historical factors that are more or less conducive to development are passed on from generation to generation along lines of ancestry.

But why does ancestry matter?

This is an old and still open question. In the past, much of the debate was focused on whether ancestors matter because of nature (the inheritance of biological traits) or nurture (for instance, the cultural transmission of work ethic or trust). The scientific community, however, has come to recognise that the dichotomy between nature and nurture is obsolete and reductive. As we pointed out in a recent discussion of this literature, people and societies inherit traits from their ancestors through a complex interaction of biological and cultural channels, with an essential role played by environmental factors (Spolaore and Wacziarg 2013a).

Relatedness and barriers to the spread of technologies

Much of the debate on the effects of inherited traits has been about modes of transmission (biological, cultural, or both), while less attention has been given to different modes of operation. How do inherited traits affect development? Most scholars in this literature have focused on direct effects – people in some societies inherit traits – say, work ethic or fertility preferences – that directly make them richer. Such direct effects, however, are only one possible channel, and not necessarily the most important one. Another key mechanism is that long-term divergence in inherited traits can create barriers to the diffusion of technologies and innovations. This is the focus of our own work.

In a series of papers, we argue that the intergenerational transmission of human traits – particularly culturally transmitted traits – has led to divergence between populations over the course of history (Spolaore and Wacziarg 2009, 2012, 2013a, 2013b). In turn, divergence has introduced barriers to the diffusion of technologies across societies. Such barriers impede the flow of technologies in proportion to how genealogically distant populations are from each other.

To measure the degree of relatedness between populations, we used genetic distance. Data on genetic distance was gathered by population geneticists specifically to trace genealogical linkages between world populations. Measures of average differences between vectors of allele frequencies (different genes) across any two populations provide a measure of genetic distance. Genetic distance has been shown to correlate with other measures of cultural differences such as linguistic distance and differences in answers to questions from the World Values Survey.

The goal of this approach is not to study any genetic characteristics that may confer any advantage in development. By design, the genes used to construct our measures of genealogical distance do not capture any such traits. On the contrary, they are neutral: their spread results from random factors and not from natural selection. For instance, neutral genes include those coding for different blood types, which did not confer a particular advantage or disadvantage to individuals carrying them during human evolutionary history. In general, the neutral genes on which genetic distance is based do not capture traits that are important for fitness and survival. Instead, genetic distance is like a molecular clock – it measures average separation times between populations. Therefore, genetic distance can be used as a summary statistic for divergence in all the traits that are transmitted with variation from one generation to the next over the long run, including divergence in cultural traits.

Our hypothesis

Our hypothesis is that, at a later stage, when populations enter into contact with each other, differences in those traits create barriers to exchange, communication, and imitation. These differences could indeed reflect traits that are mostly transmitted culturally and not biologically – such as styles of communication, norms of behaviour, values, and preferences.

We use these measures of genetic distance to test our model of technological diffusion (Spolaore and Wacziarg 2009, 2013b). Our barriers model implies that different development patterns across societies should depend not so much on the absolute genetic distance between them, but more on their relative genetic distance from the world’s technological frontier. For example, when studying the spread of the Industrial Revolution in Europe in the 19th century, what matters is not so much the absolute distance between the Greeks and the Italians, but rather how much closer Italians were to the English than the Greeks were. Indeed, we show that the magnitude of the effect of genetic distance relative to the technological frontier is about three times as large as that of absolute genetic distance. When including both measures in the regression, genetic distance relative to the frontier remains significant while absolute genetic distance becomes insignificantly different from zero. The effects are large in magnitude – a one-standard-deviation increase in genetic distance relative to the technological frontier (the US in the 20th century) is associated with an increase in the absolute difference in log income per capita of almost 29% of that variable’s standard deviation.

Our model implies that after a major innovation, such as the Industrial Revolution, the effect of genealogical distance should be pronounced, but that it should decline as more and more societies adopt the innovations of the technological frontier (which, in the 19th century, was the UK). These predictions are supported by the historical evidence. The figure below shows the standardised effects of genetic distance relative to the frontier for a common sample of 41 countries, for which data are available at all dates. The figure is consistent with our barriers model. As predicted, the effect of genetic distance – which is initially modest in 1820 – rises by around 75% to reach a peak in 1913, and declines thereafter.

Finally, our model implies that genetic distance should have predictive power at the level of disaggregated technologies. We find this to be the case both historically – when measuring technological usage on the extensive margin – and for more recent technological developments – measuring technological usage along the intensive margin. In sum, we find considerable evidence that barriers introduced by historical separation between populations are central to account for the world distribution of income.

Policy implications

These results have substantial policy implications. A common concern when studying the persistent effect of long-term history is that not much can be done today. But if a major effect of long-term historical divergence is due to barriers, there is much room and scope for policy action. Populations that are historically farther from the frontier can benefit from policies that specifically aim at reducing barriers to exchange and communication. Moreover, our findings suggest that the effects of long-term divergence in inherited traits – captured by genetic distance – are not fixed and immutable, but depend on dynamic factors (e.g. where the frontier is located), and do change (and decline) over time.

Ancestors matter, but they are not eternal destiny.


Acemoglu, Daron, Simon Johnson, and James A Robinson (2002), “Reversal of Fortune: Geography and Institutions in the Making of the Modern World Income Distribution”, Quarterly Journal of Economics 117(4): 1231–1294.

Ashraf, Quamrul and Oded Galor (2011), “Dynamics and Stagnation in the Malthusian Epoch”, The American Economic Review 101(5): 2003–2041.

Ashraf, Quamrul and Oded Galor (2013), “The ‘Out-of-Africa’ Hypothesis, Human Genetic Diversity, and Comparative Economic Development”, The American Economic Review 103(1): 1–46.

Putterman, Louis and David N Weil (2010), “Post-1500 Population Flows and the Long-Run Determinants of Economic Growth and Inequality”, Quarterly Journal of Economics 125(4): 1627–1682.

Chanda, Areendam, C Justin Cook, and Louis Putterman (2013), “Persistence of Fortune: Accounting for Population Movements, There Was No Post-Columbian Reversal”, Working paper, Brown University, February.

Comin, Diego, William Easterly and Erick Gong (2010), “Was the Wealth of Nations Determined in 1000 B.C.?”, American Economic Journal: Macroeconomics 2(3): 65–97.

Diamond, Jared (1997), Guns, Germs and Steel: The Fate of Human Societies, New York: Norton & Co.

Olsson, Ola and Douglas A Hibbs, Jr (2005), “Biogeography and Long-Run Economic Development”, European Economic Review 49(4): 909–38.

Spolaore, Enrico and Romain Wacziarg (2009), “The Diffusion of Development”, Quarterly Journal of Economics 124(2): 469–529.

Spolaore, Enrico and Romain Wacziarg (2012), “Long-Term Barriers to the International Diffusion of Innovations”, in Jeffrey Frankel and Christopher Pissarides, eds., NBER International Seminar on Macroeconomics 2011, Chapter 1: 11-46, Chicago: University of Chicago Press.

Spolaore, Enrico and Romain Wacziarg (2013a), “How Deep Are the Roots of Economic Development?”, Journal of Economic Literature 51(2): 1–45.

Spolaore, Enrico and Romain Wacziarg (2013b), “Long-Term Barriers to Economic Development”, CEPR Discussion Paper 9638, September, forthcoming in Handbook of Economic Growth, Volume 2, edited by Philippe Aghion and Steven Durlauf, Amsterdam: Elsevier, 2014.

Print Friendly, PDF & Email
This entry was posted in Guest Post on by .

About Lambert Strether

Readers, I have had a correspondent characterize my views as realistic cynical. Let me briefly explain them. I believe in universal programs that provide concrete material benefits, especially to the working class. Medicare for All is the prime example, but tuition-free college and a Post Office Bank also fall under this heading. So do a Jobs Guarantee and a Debt Jubilee. Clearly, neither liberal Democrats nor conservative Republicans can deliver on such programs, because the two are different flavors of neoliberalism (“Because markets”). I don’t much care about the “ism” that delivers the benefits, although whichever one does have to put common humanity first, as opposed to markets. Could be a second FDR saving capitalism, democratic socialism leashing and collaring it, or communism razing it. I don’t much care, as long as the benefits are delivered. To me, the key issue — and this is why Medicare for All is always first with me — is the tens of thousands of excess “deaths from despair,” as described by the Case-Deaton study, and other recent studies. That enormous body count makes Medicare for All, at the very least, a moral and strategic imperative. And that level of suffering and organic damage makes the concerns of identity politics — even the worthy fight to help the refugees Bush, Obama, and Clinton’s wars created — bright shiny objects by comparison. Hence my frustration with the news flow — currently in my view the swirling intersection of two, separate Shock Doctrine campaigns, one by the Administration, and the other by out-of-power liberals and their allies in the State and in the press — a news flow that constantly forces me to focus on matters that I regard as of secondary importance to the excess deaths. What kind of political economy is it that halts or even reverses the increases in life expectancy that civilized societies have achieved? I am also very hopeful that the continuing destruction of both party establishments will open the space for voices supporting programs similar to those I have listed; let’s call such voices “the left.” Volatility creates opportunity, especially if the Democrat establishment, which puts markets first and opposes all such programs, isn’t allowed to get back into the saddle. Eyes on the prize! I love the tactical level, and secretly love even the horse race, since I’ve been blogging about it daily for fourteen years, but everything I write has this perspective at the back of it.


  1. Hugh

    I suppose we can also posit that the ability to BS is transmitted in some populations more than others and the author Enrico Spolaore appears to have gotten a double dose.

  2. Fiver

    First of all, who says “technology” should be the mark of success? Surely duration counts – especially when we know we are destroying our planet?

    Second, basing our concept of capability to attain “advancement” or “development” or whatever it is being “measured” here even in part on specific “traits” that are inherited genetically is a just plain dangerous notion we don’t need in order to account for cultural/technological transmission. How long before Group “X” claims superiority or Group “W” is declared deficit with respect to some abstracted skill set – dropping bombs, for instance, on yellows, browns, yellows again, browns, browns, browns…?
    Why wouldn’t differences of culture, language, religion, history and the rest, including loaction, be deemed “barrier” enough, without resort to so much as one gene test?

    Third, to hang the existing, horrific “income inequality” we see globally on this model, rather than the deliberate actions of expansionary “Western” Imperialism or, perhaps at bottom, capitalism, is just too close to blaming the victim for me – or a form of technological might makes right.

    We never, ever think that any other culture would prefer to be what it was or is, not what we want to make it.

  3. Banger

    I don’t think genetics itself has much to do with any of this and I don’t think the author says it does but I think the correlation between genes and the spread of technology, or anything else, sort-of makes sense. If we seen technology as cultural practices rather than as something that solves a problem maybe we can get a handle on it. If I see people that look like me doing something I’m more liable to copy their behavior than if they look and “feel” different.

    We have the idea that we ought to not notice genetic, ethnic or racial differences but we do–we feel, initially, more comfortable with people that look more like us. Thus cultural trends will follow more quickly from that sense of familiarity.

    1. James Levy

      My question would be, so if the Euros are so smart, why were they a backward peninsula off Asia for so long? I mean, technology was well advanced in the Middle East long before Europe got in the game, and again from 500 to 1500 AD technological leadership and wealth again went back to Asia. If you want Deep History, why were the Egyptians so smart for so long compared to the Celts and Germans, and then how did Europeans lose and/or forget so much technology after the fall of Western Rome?

      European dominance is a very recent phenomenon in Deep History. If Europeans had some genetic advantage, why did it show up so haltingly and so late?

      1. Banger

        My point was that genetics itself doesn’t determine anything like technological or cultural advancements but rather that people who are genetically similar will tend to copy each other.

        1. James Levy

          Forgive me, Banger, because I was really just putting those questions out there, not implicitly criticizing you. I just remember Julius Caesar’s description of those blue-faced barbarian Britons and am wary of reading history backward–we dominate today so we must have some genetic advantage over others. Well, it was those “lazy Mediterranean” Greeks and Italians who are so often castigated today that brought “civilization” and “advancement” to Europe. None of that squares with this kind of genetic (eugenic?) thinking.

        2. lee

          I’m with Jared Diamond in that geography tends to trump “genetics” when it comes to technological development.

          What does one mean by “genetically similar”? So-called racial traits while visually obvious have so far as we know nothing to do with brain function, which in humans, is where the action is.

          That people who look more like each other tend to be more open, comfortable and sharing with one another is a cultural trait that is hopefully on the dwindle.

          Sartre observed that “human groupings encounter one another in fields of scarcity.” Humans must group to optimize survival on the one hand, and on the other will seek to exclude other groups so as to limit competition and so will invent both inclusive and exclusionary group identities based on numerous criteria that have no genetic basis whatever.

      2. fresno dan

        very, very good points.
        How many millennia was Egypt at the top? Babylonians? How long Rome? How long Chinese dynasties? Incas?
        Saying that there is some inherent factor strikes me as equivalent to saying there is something in the DNA of the Pittsburg Steelers in 1979 that accounts for their success…

  4. Alejandro

    This seems like conjecture and speculation more than science, but then again they’re “eCONomists”. Interesting trends in junk economics. Another angle to drive wedges between victims and potential victims.

    Since speculation seems to be the theme, I’ll speculate and say that nothing frightens oligarchs’ more than true solidarity of the ninety-niners.

    1. s spade

      I think calling this article speculation gives speculation a bad name. I would call it a waste of paper and ink.

  5. Eleanor

    The authors of this piece are both economists. The papers they cite are almost all economics papers. To have any credibility at all, they should have co-authors who are evolutionary biologists and geneticists, and they should be referencing papers on genetics and evolutionary biology. A few historians would have helped, too.

    I am with Hugh. This is BS. I also agree with Fiver’s comments.

    One final thought. The Japanese ought to be very genetically distant from Western Europeans. So how did they pick up western technology so quickly and with such verve? The Chinese have not done badly, either. Much better than people closer to Europe, who must be more closely related to Western Europeans — and who suffered from colonialism, as the Japanese did not, and the Chinese did only partially.

    1. James Levy

      Yes, they miss the point that the “settle colonies” did better because 1) the faced small populations that they cold destroy and 2) they brought their guns, germs, and steel with them. And this is all a frighteningly new phenomenon when you consider agriculture was developed by Asians 8000 years ago or a little more. European global domination is not quite 200 years old! And where do the Asiatic Jews fit in here (I’m going with the assumption, which is tricky, that Zionism is not a fairy tale and the Jews come from Palestine)? Aren’t Turks just as close or closer genetically to most Europeans as Jews are? How does that work with their hypothesis?

      Yes, they should have consulted with some serious historical specialists before they went nuts with the regression analysis.

      1. Glenn Condell

        ‘I’m going with the assumption, which is tricky, that Zionism is not a fairy tale and the Jews come from Palestine’

        Very tricky once you’ve read Shlomo Sand’s Invention of the Jewish people.

        Wiki: ‘Around the 8th century, the Khazars’ ruling class converted to Judaism, and from then on they cultivated relations with diasporic Jewish communities across Europe and Asia until their fall in the 10th century’

        I’m not expert or ethnically involved enough to decide whether most European Jews descend from Khazar stock – there is naturally a fervent effort to discredit such an idea, but Joseph Roth’s musings on the red headed blue eyed Jews he grew up around in eastern Galicia do make you wonder.

        Either way, the eminently practical choice of the Khazar elite, hemmed in between Muslim and Christian strongholds and acutely aware of burgeoning Jewish trade links, to adopt Judaism as the state religion, seems to argue more in favour of cultural, economic and intellectual transmission of dominant social memes than anything genetic.

  6. washunate

    It’s an interesting approach. Quite thought provoking.

    “The greater a population’s genetic distance to the population on the technological frontier, the lower its relative income will be.”

    However, I’m uncomfortable with the advocacy attached to it. There is simply no link between technology and the distribution of wealth. How we distribute wealth (ie, the political side of political economy) determines relative incomes.

    Even defining technology is difficult. Are cars more technologically advanced than trains because they’ve been developed more recently? Is extended end of life time on a life support system a better way of dying? Etc.

  7. Lexington

    This is 19th century phrenology dressed up in the pseudoscientifism of 21st century social science methodology. It’s always a bad sign when you see economists dipping their toes into subjects far removed from the areas of alleged expertise like history, genetics, anthropology and geography.
    For starters the authors blatantly misrepresent Jared Diamond’s thesis in “Guns, Germs and Steel”. Either they didn’t read the book or they are dissimulators. Most probably both. Diamond’s thesis is actually the opposite of their own: that differences in economic development (conventionally defined) reflect differences in resource distribution, NOT differences in inherent ability. Diamond actually argues that a human population will use all the resources available in its environment, and therefore if resources were equally distributed economic development would be too.
    The substance of their argument is so ephemeral you can’t help but believe it took an economics PhD to conceive it: if we define Great Britain as the gold standard for economic development (the “technological frontier” as their pretentiously call it), we can show that populations more closely related to Britain experienced faster economic development than those more distantly related. But what exactly do we mean by “related”? The authors only consider this question in terms of genetics, because they are philosophically committed to an explanation that is frankly racist, and are therefore only interested in evidence that would support that predisposition. Any number of other correlations that could be demonstrated –for example, geographic proximity, access to similar resources, or comparable methods of capital formation- are simply ignored because they aren’t useful to the authors’ political agenda.
    The fact that in certain circles this sophistry can be passed off as intellectually respectable really says a lot about the state of economics as an academic discipline.

    1. James Levy

      Forgive me all for posting too much, but I’m an historian and this really gets to me. I tell my students: no coal, no industrial revolution. It was a necessary thought not sufficient cause of the Industrial Revolution. And the Brits had been mining coal in great quantities since Elizabethan times because the privatization of the commons, the needs of the navy, and the policy of keeping the Royal Forests inviolate led to a wood shortage (that and the Tudor mania for building homes with wood and the fact that most English country people were not destitute and could build homes of wood rather than mud and straw as they had in the Middle Ages). So coal mining did not lead instantly to industrialization (it didn’t in China, either, which mined more coal in the 1400s than Britain did in the 1700s).

      BTW, the iron an coal industry first developed on the European mainland in Belgium. That’s because British entrepreneurs went their seeking new sources of coal and cheap labor in a country that owed its existence to British foreign policy, not because of some genetic fraternity between Belgians and Britons.

  8. anon y'mouse

    so, isn’t this just the old “our culture makes us superior”? rather than “our Aryan blood makes us superior”?

    and yes, who gets to determine which culture is superior and why?

    I would rather a culture that nurtured more of its individuals into a healthy lifestyle, than one that nurtured some few into superwealth and great intelligence, and the rest in abject poverty which they are viewed as “deserving” due to their inferior traits/haircolor/whatever.

    1. anon y'mouse

      although, I don’t deny that passing a culture of the superior class down from generation to generation ensures that the members of that class stay on top. I’ve seen multiple studies that show that.

      but that is usually along the lines of nepotism, and the additional resources that wealth provides that are shared with group members and from which outsiders are excluded. sociologists may call some of that “culture” or passing the knowledge and markers/indicators to the next generation for their use. it’s one of the things they claim can be gotten from attending ivy league schools, and why the seeming meritocratic behavior of those schools is so important to maintaining the myth that “we all have an equal chance.”

  9. Chauncey Gardiner

    Noticed that their references failed to include either the work of Edward Osborne Wilson or Arthur Robert Jensen, with both of whom they seem to share similar views.

  10. bluntobj

    In light of all the comments above, where are the early empires or advanced civilizations today?

    Epigenetics? Evolution? Enviromental effects?

    All the comments here throw this study under the bus because it hints that there might be genetic reasons for poor economic outcome, which in America translates into racial inequality due to long term genetic factors, which must be avoided at all costs.

    Amusingly, it is this avoidance that actually facilities racism and the slide into a new aristocracy and nobility structure. See Lambert’s post on Devolution of the citizen today.

    If I take the idea presented and apply it to US history, then I would note that the immigrant genetic populations also passed on a political dimension that allowed them to accept government on the basis of citizen equality rather than a history of nobility and aristocracy. However, populations that have a history of submission to aristocracy or tribalism may find a preference for the welcoming arms of the state, to which they may belong.

    I would suggest that such a hunger for belonging as a consumer rather than a citizen among equals is converting people to the status of “consumer,” not “citizen.” Citizens have rights, equality under the law, and social responsibilities. Consumers are cattle, to be bought, sold, milked, and slaughtered.

    Those that define people into minority groups based on racial lines, and awarding them the largesse of the state based on their “inequality” are making them consumers of the state, and therefore cattle. Which begs the question; do those definers also long for the return of a class based system with themselves on top?

    Worth pondering.

  11. Abe, NYC

    I wonder how the genetic distance between North and South Koreans explains the difference in their incomes. Or is it, perhaps, the geographic factor of the latter being adjacent to communist China?

    Well, Russians thought they had a genetic advantage over “Japanese monkeys” but it didn’t prevent their utter defeat in the 1905 war. Hitler quite explicitly believed his people had a genetic advantage over the “Asian Hordes” of Russia, but once again it didn’t quite work out they way he planned.

    Japan is especially remarkable. They were very, very far from the technological frontier in 1860s. Genetic distance, huge. Cultural distance, if anything, even huger. Yet in only 30 years they closed the technological gap. What’s that about?

    1. bluntobj

      Elimination of most warriors.

      Utter destruction of industrial base.

      Innate Nipponese cultural imperatives to conform & belong.

      Genetic shift from warrior type to builder type after the war.

      Complete rebuilding and re-patterning to US Society.

      Closed gap.

    2. bluntobj


      Invasion of Russia pre-WWII did not turn out so hot for Nipponese.

      Paper is about genetic predispositions that act in much more subtle ways than eugenics or Hitler attempted.

  12. RanDomino

    Academia is where three-sentence papers somehow turn into messes like this. Yes, if inheritance exists, then richer ancestors make richer offspring! Okay, turns out it’s only a one-sentence paper.

Comments are closed.