Conversations with Tyler - Gregory Clark on Social Mobility, Migration, and Assortative Mating (Live at Mercatus)

Episode Date: February 19, 2025

How much of your life's trajectory was set in motion centuries ago? Gregory Clark has spent decades studying social mobility, and his findings suggest that where you land in society is far more predictable than we like to think. Using historical data, surname analysis, and migration patterns, Clark argues that social mobility rates have remained largely unchanged for 300 years—even across radically different political and economic systems. He and Tyler discuss why we should care about relative mobility vs growing the size of the pie, how physical mobility does and doesn't matter, why England was a meritocracy by 1700, how assortative mating affects economic and social progress, why India industrialized so late, a new potential explanation why Britain's economic performance has been lukewarm since WWI, Malthusian societies then and now, whether a "hereditarian" stance favors large-scale redistribution or a free-market approach, the dynamics of assimilation within Europe and the role of negative selection in certain migrations, the challenge of accurately measuring living standards, the neighborhood-versus-family debate over what drives mobility, whether we need datasets larger than humanity itself to decode the genetics of social outcomes, and much more. Read a full transcript enhanced with helpful links, or watch the full video. Recorded February 5th, 2025. Help keep the show ad free by donating today! Other ways to connect Follow us on X and Instagram Follow Tyler on X Follow Gregory on X Sign up for our newsletter Join our Discord Email us: [e-mail] Learn more about Conversations with Tyler and other Mercatus Center podcasts here. Photo Credit: Chris Williams, Zoeica Images

Conversations with Tyler is produced by the Mercatus Center at George Mason University, bridging the gap between academic ideas and real-world problems. Learn more at Mercadis.org. For a full transcript of every conversation enhanced with helpful links, visit Conversationswithtyler.com. Hello, everyone, and welcome back to Conversations with Tyler. Today I am chatting live with Greg Clark, the economic historian. I think it's fair to say that Greg.

is the most interesting and most influential economic historian of the last 20 years. His book from 2007, A Farewell to Alms, presented a new theory of economic growth, human progress, and the Industrial Revolution. I ended up as one of the blurbers, and I called it, as I wrote in the New York Times, the next blockbuster in economics. His book after that, The Sun, S-O-N also rises, surnames in the history of social mobility, among other other. things, argues that rates of social mobility have been much less, much more static,

much harder to change than many people believe. Greg spent much of his career at UC Davis. He is now a professor at the University of Southern Denmark, and he hails from Scotland. Greg, welcome. Thank you very much. Great to be here. I have so many questions about your work. Let me start with mobility, a point where I think we don't agree. So I see mobility across freer societies is much higher than you do. And I worry that you're treating mobility too much in terms of relative ranking. Your kintile, how well is that predicted by your parents' kintyel or desal of income? But if you just think of mobility as having a much better in different life,

freer life than your parents, aren't rates of social mobility just immense? No. The amazing thing is, if we even go back to medieval England, rates of social mobility were just as high as they are. now. And, I mean, if you want to take these other dimensions of freedom of expression or social neighborhood that people were in, again, there's no evidence that that has in any sense improved now, right? I mean, people are just as divided in terms of the types of groups that they meet with as they would be 500 years ago. And so I really want to stick with this idea that in a society like

England, we have not in any way improved rates of social mobility in the last 300 years. But that's focusing solely on relative rankings. So if I visit Liverpool and I look at Paul McCartney's home, I know that's an extreme case. But in Liverpool, living standards are just much higher than they were earlier. People have many more sources of freedom. It's true that where they fit into the deciles or other relative rankings, maybe that hasn't changed much. But why is that the relative concept of social mobility. That's what I don't get. Well, it's absolutely the case that we're now 15 times better off than we were in 1800. But it's still, I think, a very important feature of society and one that, you know,

people are obsessed with. I'm not obsessed with it. But it turns out most people are, right? I don't think they are in America. I think they're obsessed with the absolute living standards they enjoy, whether those go up or not, and not so much about how the person in Mississippi compares to Bill Gates, I think it's exactly what people are not obsessed with. Right. It's legitimate to say, I see your question, and I think it's unimportant, right? But I still think it's a fascinating feature of societies, which is how are people between generations moving in relative position within societies?

And the other thing I would say is that, you know, You know, that gain in material living standards is actually in some ways a lot less important than you might think. I mean, I've gone to, you know, Dr. Johnson's house in London from the early 18th century. I'd be perfectly happy to move in and live in that house now. With no penicillin, no good dental care. Yes. There have been definite improvements in health care and other things. Electricity.

Right. But as I say, I mean, in some sense, you're just saying, okay, I want to concentrate on growth, right? And I think that that's the crucial element of society. And if all of that growth goes to 10% of the society and not to the rest of society, I wouldn't care about that, right? Whereas as I say, it seems to me just in common observation that certainly in Britain, where I come from, that people do have this fascination with relative position in society. and that people are obsessed about who's going to the elite universities, who are the members of parliament, what are the backgrounds of these people?

But isn't that the problem with Britain, right? It's an economy that is more or less falling productivity since the great financial crisis. It's far too stultified. It's too status conscious. And what we need to do is distract people from relative rankings and just get them thinking about the absolute size of the pie. Well, one of the reasons that I went to Denmark was because of the fantastic data that they have in the register data on people's social position in Denmark. And in this new book that I just completed the draft of, one of the things that's pointed out is social mobility rates in modern Denmark are no higher than in Britain. It's just... This I believe. It's not correct. to think of Britain as an immobile society.

They both immobile societies. Denmark, people, they go to the same high school, they hang out, they eat those weird fish sandwiches, and they help each other out, and what you're born into more or less determines how you, your kids, grandkids will do in Denmark. But I think the Danes themselves

would actually think of themselves as a very mobile society and as a very open society. So that's why someone who, interested in societies, I mean, it is fascinating to me that you can change so much about social structure, say, between England and Denmark, but somehow not change one basic fact, which is just how connected are people to their parents in terms of their social outcomes, and also how little influence social institutions seem to be able to have on that connection.

And I actually draw from this a comforting fact, which is to say meritocracy was achieved much earlier than you might have expected. Because what you would find in a truly meritocratic society is that the only things that really determine social position are going to be people's genetic inheritance and randomness. And that status seems to have been achieved in England already by 1700. And so I actually draw kind of this different lesson, which is that not only have we achieved growth in the modern world, but we've also achieved meritocracy hundreds of years ago. And I would think that a lot of people would regard that as a pretty radical claim about the nature of modern society, despite your skepticism. Let me give you a different reading of your work that probably you'll disagree with, but let me get your reaction. And this I call Strauss plus Brian Kaplan. So one way of reading Greg Clark is that he shows that social mobility is quite high,

but the only path to social mobility is geographically moving around. So a simple example, I think media and household income for families from India that have come to America, it's $158,000 a year, which is remarkably high. And whatever it was in India, it was not close to that. So they moved. They're doing incredibly well. when people move from, say, the rural south to the northeast, during the Great Migration, they do much better, that physical mobility is what works, and it's what overturns these hierarchies. And a lot of your data sets seem to be about times and places where not that many people are moving a lot.

But mobility simply works, physical mobility. True or false? Absolutely. And I agree that, I mean, and so that also clearly says that there are cultural and social kind of constraints in society that allow some of them to be very high performing and some of them to be less well performing. But then what's interesting and remarkable is that in this new manuscript, we can actually trace people who move from Britain to Australia, Canada, and United States. And what's interesting is that their material welfare increases very significantly,

but their relative social position doesn't change and somehow is preserved across these different societies. And so the things that are kind of holding back societies as a whole, it's very interesting that it doesn't seem to affect relative social position, right? And so as I say, that's why I'm a relativist and you're an absolutist. Let me tell you if this further inference would be justified. You're not a pessimist about the importance of environment. You're a pessimist about the ability to reshape an environment when most of the people are still around. True or false? Yes.

as I say, the environment really matters. It's just hard to change it. So in that sense, the weight you assign to genes is still up in the air. Because when we see the environment change a lot, migration, the effects matter a lot. Yeah, but it seems to me that societies, they come with different constraints, but what's very interesting is that people's ability to operate within those constraints seems undiminished across different societies, and the same factors seem to determine that. And so I've actually done some work on Hungary under communism, where we again, using surnames,

we can identify who were the descendants of the previous elite. And interestingly, in things like admission to medical school, it didn't change under the system of communism. The same elites preserve themselves in the political sphere. that elite kind of disappeared from Parliament for a while. When the free market system was restored, that elite just emerged fully again into the political sphere. And so what's interesting, as I say, is you can change the overall constraints on the society,

but it still is interesting that relative position seems to be determined in some very kind of physics-like way within different societies. Now, how do you think about the social returns to more or less ascertainive mating? Say in the United States, do we have too much of it, to a little of it? So if we had more of it, you'd have, say, very smart or determined people marrying those like them, and you might end up with more innovation from their children and grandchildren. But you might also be messing with what you'd call the epistemic quality of the median voter, right?

So there's a straight-off. How do you think about that? What side of the margin are we at? So assorted mating turns out to be a fascinating phenomenon. And in this new book, we actually have records of 1.7 million marriages in England from 1837 until now. And what is astonishing in England is the degree to which people end up assorting in marriage. And so that basically they're matching with people that are as close to them, essentially genetically as their siblings in marriage. and it's really interesting because people could mate in any kind of way, right?

You could think I want the tallest person, the handsomest person, the youngest person. But for some reason, consistently, people seem to want to match to people who are close in social status. Now, that doesn't affect anything about the average level of ability in a society. But if it's consistently followed over generations, it will widen the distribution of ability. And are we doing too much of that or too little of it in the United States? It depends what you view is. If you think that the engine of high-tech society now like the United States is the top one or five percent of the ability distribution, then you would say the more assortative is mating, the more people will be in that extreme. Yeah.

And the greater will be economic growth. Yeah. And so in the new book, I actually speculate about was assortative made? in northern Europe a discovery of the late Middle Ages that actually then help propel things like the scientific revolution, the Enlightenment, the industrial revolution. Because as I say, it's a remarkably constant feature of British-Sy. We can only trace it back to about 1750, the actual degree of assortativeness. And so in that sense, you can't have too much, if that's your view about how society operates,

right. Or at least we could have more of it. There might be some margin where you'd have to do much. But it does produce more inequality. And so if you're worried about inequality in society, you don't want disorder to mating, right? I mean, the one way to correct a lot of inequality would just be to have much more random matching. But one of the remarkable things about Denmark is education is essentially free until you're age 24. They give you subsidies for your living expenses, for child care provision, it's all available. They've compressed the income distribution quite sharply.

There is this periodic survey of how well students do the PISA measures. Nordic countries have not reduced the inequality of PISA measures compared to much more unequal societies like the United States. And so again, it's just kind of interesting that high degree of inequality is still found within these societies. And it turns out that in Nordic societies, people are mating again very strongly, assortatively, even now. And so that is the thing that you would worry more about is that there is going to be this trade-off between assortative mating and the degree of inequality in a society. So let's say the Spaniards and others, they come to the new world. There's a lot of pairing off. Some of it is violent and coercive, of course, but a lot of it

seems more random than what you might expect from Jane Austen's British Victorian society. What's the implied prediction about what results from that? There's going to be less assortative mating, at least for a while, right? Yes. And you would, the implication would be you'll get just a narrow distribution. But do we see that? It seems we see very high inequality in those societies. Well, remember, there's potentially a difference between inequality based on things like wealth ownership and inequality and abilities or kind of educational potential that you would see within a society. But definitely, I mean, there's clearly going to be this association between how assortative marriage is and how much inequality you get.

So by the way, Neil Cummins and I have a paper that just came out in Plus One, which is about hypergamy, which is the idea that, very common idea, that women tend to marry up because men value physical appearance more than women do, and that there's this trade-off that exists in the marriage market. And interestingly, for England, going back to 1837, we claim that there is no hypergamy, that essentially men and women end up matching in social status in marriage. And And it seems to be that it's just a complete dominance of social status in determining unions within this society. For England, I believe that. You think it's true for most of the world?

Well, the interesting question is it's definitely true for a bunch of earlier societies that the matching was much less tight. And so, for example, there's a whole bunch of earlier societies where cousin marriage was a very important form of marriage. And the problem with cousin marriage for assortativeness is most people don't have a lot of cousins at the right age and gender. And so it ends up that you have to marry a random cousin. And it turns out that the modern British or even the 19th century British are matching much more tightly in terms of marriage than it would be the case if you just match to a random cousin. In your view, has cousin marriage been a big problem for the Arab Middle East? that you end up with something that's too clannish? What I would say is if it's systematically carried out,

it should lead to a kind of reduction in the distribution of abilities within a society compared to the very assertive kind of northern European pattern or other patterns. I honestly don't know whether it actually leads to these other problems in terms of the clannishness of society, right? I mean, potentially, yes, but it's not something that I've actually studied, yeah. It at least seems that today something about the caste system is finally paying off for India.

So from South India, you have these incredible chess players, right? That's G-loaded, CEOs and tech. Why is it that now the caste system, in this one particular way, is succeeding, but in earlier times you don't see anything nearly as comparable? Like what has changed? What's the environmental change? And doesn't that mean like environment really, really matters? It's not all just genes.

Oh, no. In terms of overall economic performance, I mean, in my earlier book, right, Farewell to Arms, it said there's essentially only two great problems in the economic history of the world. The first is the incredible long delay in the arrival of the industrial revolution. Right. Right. And then the second puzzle is the incredible divergence. of societies since the Industrial Revolution,

where now you get these differences of about 50 or 60 to 1 in material living standards. And this is really kind of illustrated when you look at a society like India where because of this caste system, you had this super elite the Brahman caste, which preserved itself for many, more than a thousand years. Clearly now you see,

when these people move to the United States, who are the new elite of the United States? These are Indian immigrants in the United States, who are kind of a super elite within this society. And then the stunning puzzle is, why did all of that talent coexist with an incredibly stagnant Indian economy? And stagnant even once it was opened up

to the forces of the modern market by the British, and even once you had kind of brought in kind of British civil institutions, British legal institutions, free trade, free capital markets, low interest rates. I mean, this is one of the kind of stunning puzzles of the modern world. And even though I write about that in that earlier book, I have to confess, I have no idea why a society like that can remain so unchanged after the arrival of the British and not actually start transatlantic. transforming itself until the last 20 or 30 years. I don't doubt the answer is complex, but isn't part of it pretty straightforward, and it has to do with state capacity. So the British only invested in a few kinds of public goods,

ones that would help them either trade with the country or defend it. There was very little investment in human capital. So in some ways it was nominally somewhat free. But in terms of actual market size and scale and building up of high trust institutions, the British were arguably even a negative influence. right? Rates of growth are pretty low. Even under Nehru socialism, India has a higher rate of growth. Why isn't that, again, far from a complete resolution of the puzzle, but a pretty simple first-order answer? It may not seem that the British contributed much, but if you even look at the kind of Anglo-Indian group that developed in India, that was massive. I mean, think about how big India is relative to Britain. This was a massive potential entrepreneurial class. in India. And the British also had a policy that allowed absolutely free migration of entrepreneurs

into India. So the Bombay textile industry, something like 10% of it, was owned by a Jewish family that had come from Iraq, the Sassoon family, that, you know, that the British, as I say, welcome these entrepreneurs. They encourage free trade. And so I think, I don't think you could underplay how significant an intervention that was by the British in that society. Everyone is tending to judge the India now by the results. But, you know, even Karl Marx writing in the mid-19th century confidently predicted that the British had created the next industrial colossus in India and that that would kind of overwhelm the British in turn.

And it is one of the great puzzles of history is why, India never developed under the British. It just seemed that this was the path. But could it have been too much ascertain of mating, that there's something to an oaring model where for a lot of production processes, it's the weakest link, the least well-educated link,

the biggest source of social disorder that disrupts a town, a village, a firm for everyone else? And in terms of the oaring model, India back then just wasn't doing well at all. Yeah, except, you know, I've studied a lot in my earlier life, on the cotton textile industry. And it turns out, I mean, as I say,

that was one of the major industries of the 19th century. You could run an entire cotton mill with three skilled managers. And the tasks of people at the lower level there are extremely simple. Don't require literacy. In Japan, we're performed by 14 and 16-year-old girls with high,

competence, fantastic results. Now, when we look at modern manufacturing processes, they can often involve high levels of performance by workers and huge costs if workers fail to perform. But it looked like in the 19th century that you had these kind of failure-resistant techniques. Someone in a spinning mill, if they mess up, the thread breaks more often, right? But that can all be repaired and, you know, it's all observable. And so in modern high-tech manufacturing, you can see this problem, but not in 19th century India, right?

And so I still say... There's a whole supply chain, there's the networks and the search of getting the right people to those jobs. So maybe it involves a lot of different moving parts and not just what's under the roof factory. So I think some modern Indian, you know, very rich entrepreneurs

should have a prize that would be devoted to someone who could explore, why India didn't successfully industrialize under the British in the 19th century, because it's one of those stunning mysteries of history. And as I say, it's easy for people just to say, oh, it's the sclerotic English institutions, it's the arrogance of the conquerors, it's the caste system in India.

But none of that actually, I mean, if you look at the details, none of that successfully explains what happened in India. What about the hypothesis? There's something like akin to the Asian tiger mom. To enforce it, you need a network. It's very hard to just do it on your own. And for the network to be there, you need many, many moving parts, major social changes. India back then maybe didn't have it. Today, at least significant parts of India have their own version of the Indian tiger mom who kicks the kid's butt across the room if they don't finish at the top of their high school class. And that that's a social network. It's determined by culture. It's super hard. to build up just by having a few British people arrive with ships. And finally, we have it. True or false? Well, except, as I say, when the British arrived in India, the British were open. The important thing that people maybe have difficulty understanding about British upper class

was it is an incredibly open upper class. And they were absorbing people coming from all different parts of the world. The Sassoon family, for example, ended up writing poetry. against World War I and also as the chief aid to the general fighting World War I. And so they had absorbed into British society lots of foreigners many times before. And so in India, they were actually absorbing a lot of upper class Indians into British society. And what I'm saying is to make the kind of revolution that we would expect in India, you don't need 10 million people,

you only need a couple of thousand, it would seem, to lead India, you know, to modern economic growth. And that's what's so puzzling is that, you know, it's not, you know, you might explain all of this stuff, but all you need is some deviants. And so take an example of this, Indian mills underperform British textile mills. In 1940, there were 450 Indian textile mills.

there was not a single one that achieved the average level of productivity of the English mills. How is that possible when you have this varied set of entrepreneurs, varied set of people that you just cannot kind of match the performance that's going on in this other society? I remain puzzled by that. Say we look at some other extreme example, you know, Korea, South Korea. So in 1960, it's maybe poorer than some parts of sub-Saharan Africa. Africa. Today it's a fully developed country. I don't know what happened there, but I know it's not a big genetic change. Something in the culture. They got their act together, and then they did great.

So what's wrong with just assigning these puzzles to culture? It doesn't mean we can explain them in the predictive sense. India somehow developed a better culture. South Korea certainly did. That we pretty much know, right? Why resist that kind of explanation? Well, see, I'm not resisting here, right? What I'm saying is, I'd like to, you know, having now spent many years studying economic history, have finally come to, I think, modesty and to say that, look, there are some problems that just defy any serious explanation that we make no progress with, right? But then say there, it turns out there are some other things where we can explain surprisingly

well what's happening, right? And so basically what I'm saying is here's the things that, you know, why I turned to studying social mobility is that here was something which actually showed this law-like characteristic and where you could actually understand the processes and the logic of this and why I kind of turned away from studying things like, why isn't the whole world developed, is that it just seemed impossible to actually make. make progress on that, because once you just say, okay, it's some kind of cultural event, then what are you going to say after that, right?

But this is where I worry. You're a bit too much of an economist. If one insists on these very mono kinds of explanations, everything testable, measurable, then surely so many things in human history are hard to explain. But if we take a more humanities-based view, more pluralistic, even just ask Korean people themselves, they're full of explanations. And they'll often just say, well, we got our act together. it doesn't satisfy many economists, but maybe in some ways it is good enough.

If we just have a broader sense, in economics, you know, there's Ricardo, there's marks, explanations are supposed to take a certain form. Maybe that's just our disease. Well, having written on the history of the Indian industrialization, in 1999, I dragged my spouse and three children on a five-month tour of India, seeking to try and just by being on the ground there to see if you could understand anything more about why this economy, which was still at that stage,

you know, lagging enormously behind. And I would actually, we traveled on train all the time and we ran up talking to Indians. And it was interesting to ask people, you know, why is India so poor? But it turns out that people have all kinds of answers, but they're easily testable as false. They say, oh, it's the population.

We have too many people, right? And we know now, of course, that that actually is not going to make any difference, or it's the corrupt politicians, or it's the education system, stuff like that. And so the problem with, as I say, this kind of pluralistic, open humanities type explanation is it doesn't work. It's time to get on board with the scientific revolution. We can only explain things if we have these mechanistic, closed form, empirically testable explanations. otherwise it's just conversation. If we take England, when I read your book, Farewell to Alms,

I took you to be ambiguous, but when I reread that book through the lens of your later papers, it seems to me you're saying there was an actual genetic change in English society because of who was marrying whom and having kids with whom, and thus people, you know, saved more, became more conscientious, more forward-looking. Yes. Now, if that was genetic rather than call. cultural. Why is it today, when I go to England, there's a lot I'm disappointed by when it comes to conscientiousness. I mean, really quite a bit compared to say the rest of Europe,

and that to me suggests it was much more cultural than genetic. The genetic change was probably small, the cultural one huge, because it hasn't persisted. I mean, the differences in output per person in England compared to the rest of Europe are actually relatively minor. And if you look at other kinds of productions like scientific production, literary production, other things like that, there's no vast difference, right? But it's a slightly below average, mediocre performance, a bunch of stars in the South, star achievements. But if it were this general trend through the population as a whole, North England should be highly conscientious. It doesn't seem to be that much compared to, say, the Netherlands, at all.

Well, why don't... Never mind Denmark. Right. Well, two things I want to emphasize here. So one is I think the processes that were operating in pre-industrial England reflect general processes operating in northern Europe, where all of these societies show this phenomenon of survival of the richest going on hundreds and hundreds of years before the Industrial Revolution. We know very clearly that there are genetic differences between people at the top of the social ladder and people at the bottom, and that that was going to change the underlying genetics of these societies,

and it seems to be, as I say, a general feature, right? So the first point, so I don't think of England as being that different from these other locations, right? The Industrial Revolution has spread out much more across Europe than you might think. There were accidental factors that propelled it to prominence in England. In the new manuscript, what we're actually able to, I'm able to, to do is track the reproductive success of people since 1750. And there was a period from 1850 till the 1920s or 30s,

when an astonishingly low fertility emerged amongst upper classes in Britain. And that was also compounded by very heavy losses of the upper classes in World War I. So 20% of men of that generation in the upper classes died in World War I. But reproduction rates were at like one child per family or one and a half for 50 or 60 years in the late 19th century amongst this group. And so the relative size of the upper class in Britain actually shrank dramatically in the course of this period. And so that's one potential explanation of, again, why? kind of British performance has been relatively lukewarm since about World War I, right?

Because as I say, it did go through this surprising and dramatic kind of transformation socially where you're really losing a lot of this upper class. And by the way, one interesting thing was how few of this upper class actually ended up marrying in this period. So it was somehow a kind of renunciation of marriage

and of family at that time and kind of puzzling, right? And it hasn't persisted. I mean, now in Britain, fertility is pretty neutral between upper class and lower class, but there was this 60-year period, and that's associated

with quite a dramatic decline of Britain's kind of entrepreneurship and leadership in the world economy. And so there is this kind of intriguing possibility that this actually was an important kind of historical event. But the genetic perspective, doesn't it imply that

societies close to Malthusian margins should actually become more and more conscientious over time. Because just to survive, you've got to take care of whatever savings you have and that that trade should evolve. But just casual empiricism doesn't seem to show those societies as being more conscientious. But here's one element of casual empiricism. So if you look in modern economic competition, we can kind of rank societies by how old they are. So China is extremely old. If you go to other parts of Southeast Asia, these are much kind of younger societies in terms of settled agriculture. And what you observe in Asia is that laborers exported from China to work on plantations elsewhere in Southeast Asia have become

the entrepreneurial class in all of those societies, in Indonesia and Malaysia and Malaysia, in the Philippines, and that somehow the history of different societies is still predictive of how people are going to do in modern economic competition. And the question would be, you know, putting it back to you, what kind of cultural explanation would there be for why that type of history would actually matter so much in terms of modern competition? But one argument just would be that under the kind of the anvil of the Malthusian era, these societies were just transformed more by these selective pressures applied for thousands of years, and that that then emerges in terms of kind of basic behavior of people in the society that makes them perform better even now. But the most conscientious places, Denmark being one example, as you now live with, they've been above subsistence for quite a while.

The Danes had a somewhat mature nation-state quite early, as did England, some relative form of stability, markets with food supply and transportation networks. Again, you could make a point about China, but if you just test that point out of sample, where are the conscientious peoples? It seems it's in the places the furthest from Althusian equilibrium, where selection pressures are the weakest. Now, it's true in Northwest Europe that living standards in the pre-industrial period, material living standards were significantly higher than it seems in Asia, right? And that shows up in a whole bunch of ways.

For example, people at higher living standards consume alcohol. It's an expensive form of calories. In Asia, there's very little consumption of alcohol, and that actually shows up now in terms of people's tolerance for alcohol. Again, dairy products in Europe, they're widely consumed in Asia. No, again, they're too expensive. And that shows up again in people's ability. to absorb milk, but because you're at this higher material standard doesn't mean to say that

the Malthusian constraints are not still applying, right? And so that there are relatively rich Malthusian societies, but they can still be societies where the conditions of reproduction are such that people are constrained, that they will only reproduce successfully if they're above these living standards. And that can be because of various social constraints about when people get married, how fertile marriages are. And so as I say, the fact that Europe was relatively rich, and we can even extend this back to the Stone Age in Northern Europe, where again, skeletons from that period are very robust compared to somewhere like Japan in the earlier period. That doesn't mean that these Malthusian constraints didn't operate. And one classic

example of this is when people arrived in Tahiti, that was clearly a Malthusian's society. There's a bunch of people stuck in an island and, you know, with limited resources, and you were going to reach some kind of population equilibrium, and you were clearly going to be under these Malthusian constraints, but it was materially quite well-resourced society, but you still have these constraints. And as long as you have these constraints, it's possible then for people who are doing better economically to produce more children and doing worse economically to produce fewer children. This is maybe a side point, but it seems odd to me to think of them as Malthusian

when they have the greatest ability to transport themselves over long distances of almost any society, and they settle much of the South Pacific, and the idea that mobility gets you free land, free supply of fish, whatever, they seem to have realized that better than almost anyone. And the Europeans, when they went there, they didn't feel so sorry for the Tahitians, right? Oh, no, they thought the Tahitians were letting me incredibly well. Yeah. So it wasn't Malthusian because of transportation and mobility. No, no, no. But they were isolated and they had these very limited resources. And it turns out why were living standards so great? Two things. They had murderous internal warfare that disposed of a lot of people. And the second thing is that they practiced very strong degree of infanticide. And they were killing between a third and a half of all children, born in the society. And so it was a Malthusian society. But it turns out there are lots of,

Malthusian societies where people live at relatively high living standards. Well, in what sense is it Malthusian then? That the regulating mechanism is not starvation, seems almost by definition, to make it not Malthusian. No, no. To be Malthusian, it just has to be a society where there's going to be a positive association between fertility rates and living standards, right, and where there's a limited supply of... But that's a funny definition for Malthus. I mean, it's my definition.

Clarkie. No, no, I see, this is a widespread misinterpretation of Malthus, I think, is that Malthus is about low living standards, right? And so I think my earlier book, A Farewell to Arms, one of the actual innovative elements of that book was to say, let's take apart these two different elements of Malthusianism. and one is the element that you're forced to an equilibrium where the birth rate equals the death rate but the second is that that equilibrium does not necessarily imply relatively low living standards and the way this shows up is

after the black death in Europe, which increased mortality rates, living standards in somewhat like Britain in 1450 were not again equal till the end of the Industrial Revolution, right? But you could tell this was a static popular in England at that period. There were tiny numbers of people.

There were less than 2 million people in England by 1450, but it was consequently a Malthusian economy, but an incredibly rich Malthusian economy where people, when they talked about their diet, they talked about the daily meat that they would eat. And so they really were living at high material living standards. We can go back and look at the houses they constructed in that period. people here in Arlington would be happy to move into some of these medieval houses.

Under your current view, is foreign aid to sub-Saharan Africa counterproductive? And I'm not talking about corruption or siphoning it off. Those are clearly problems, but just aid as a brute, abstract concept. Does it counteract itself through Malthusian or what I would call Clarkian mechanisms? Because I think you used to believe that. There are societies like Malawi in sub-Saharan country. Africa, where there is consistent economic progress, but that progress gets eaten up in terms of population growth. And so that living standards really have not managed to increase for 50 or 60

years in these societies because they still depend very heavily on agriculture. There's a limited agricultural area, and better technology then induces more people. How could you best help such societies. It would be somehow by breaking that link between resources and population. So industrialization, if it's possible to achieve, would be fantastic in these societies. And the second thing would be limits on population growth. And it looks like those limits are coming and that we are going to see such a transformation. A lot of the say it is public health, right? So more people survive, more people live longer. Right. Oh, no. That all seems to me to give them better lives. It may not always show up in per capita GDP. But even though, as I say,

there still is this kind of quasi-malthusian link between population and living standards in these societies, that doesn't mean to say that people wouldn't be better off if you give people more resources. And so if you care about the population in Africa and their living standards, then there's nothing to say that aid isn't a good thing in this case. All that you can say, though, is, look, a bunch of that aid will result in more population growth, and so it will undercut the ultimate effects of that aid, and it would be much more effective if somehow you can actually transform these societies so that they're not heavily dependent on limited agricultural resources.

Now, you wrote a piece published in Quillette, and you use the word hereditarian, and you say, I'm a hereditarian, and that means a lot of redistribution of income is a good thing. oversimplifying your message. But insofar as one is a hereditarian, what are the policy implications of that? Oh, I think if once you recognize that a lot of our outcomes are actually the product of inheritance and are not mutable, they're not changeable, then that fits perfectly well with a society that I like living in, Denmark, where there's a huge amount of redistribution effectively being done. And so I think these things go together. I mean, you should recognize that, you know, a lot of things happen to us that we don't control. There are accidents of our history,

our family history, and that a good society is one that doesn't magnify those differences between people, but rather can seek to compress them. And one of the interesting is about Denmark. It's stunning to me when I go there. Tax rates and people are so high, but it's still a highly productive, technologically innovative society. And so it's proving that you can have a surprising amount of kind of compression of income differences and redistribution and still have a perfectly functional society. But isn't the implication in a way the exact opposite of that, that if the way people can advance is by moving, Denmark is pretty stingy with its migration policy. And Denmark should have lower taxes, lower welfare, to attract the higher quality of

immigrants, say from South India and other places, and they should be more open, that would make them much more productive, make the people coming from South India way, way, way more productive, be good for the whole world, because Denmark is closer at to the technological frontier. We see this with GLP. And it's exactly an argument against this kind of little closed. We all went to high school together. We're going to have a welfare state with high taxes approach. Right. Well, I must say that, so there is a problem then in Denmark, which is that it's a problem. It's a, It replies on people not taking huge advantage of this welfare system, which is very generous. Immigrants coming to Denmark have not responded in the same way.

Well, maybe you're taking in the wrong immigrants because if there's a welfare system and high taxes, you're not selecting for the people who are going to do the best, unlike the United States, which gets all these Indian CEOs because you can get richer here and stay richer. Right. And now, actually, in Danish politics, there is a strong argument. about what type of immigrants you want to attract. And so throughout Europe, in fact, this has become a huge issue. But you've got to get rid of these high taxes to get the good ones.

Well, that's a good question. I mean, not, I mean, Denmark offers a lot of other good things in life, though I must say the weather is not one of them. But it is actually interesting, yes, how limited immigration has been from places like, say, Vietnam or India or stuff of that to places like Denmark. because these immigrants would be very successful within this society. And the more the Native Danes are below replacement fertility, the more urgent it is that you lower taxes and attract the best migrants, I would think. So you should just be like a full-scale classical liberal, low-tax regime.

Yes, you need a safety net, but not too much because that will attract the wrong immigrants. People that come to America, they know they've got to make it on their own, right? And that attracts, on average, the right immigrants. Yeah, but you could see every day in Denmark the benefits of having so unskilled workers earn much higher wages than they would in the United States. People can live at a decent living standard. I mean, I'm living in California part of the year, and it's just shocking the number of homeless people there are everywhere, right? Within a mile of my house, there are people living homeless in California, and it just doesn't exist. this in Denmark. And so I understand perfectly the Danes desire to preserve this. But the other

problem that Danes have is there's only five and a half million of them. They cherish their culture, their history and stuff like that. And they, you know, one of the things they would fear about immigration is that already, you know, if you walk in the streets of Copenhagen, the majority of people are speaking English to each other. And so the other thing I think is that would limit immigration to Denmark is that people really do have this cultural identity. And one of the things that they wanted to insist was that immigrants actually have to assimilate.

And it's actually... I'm all for that. Right. And it turns out it's perfectly possible for someone like me to not assimilate and speak English in Danish society. It is kind of an intriguing issue, though, about whether it should we become... more free market so that then we could have a different kind of attractiveness to different sets of immigrants, right?

After you moved to Denmark, southern Denmark, what was the biggest surprise for you? I was surprised at how kind of communitarian Danes were. So at the university I'm at, every Friday, they gather in a lecture room to sing songs together, right? And also, you know, there's an annual Christmas party and the university. They have 4,000 people eat dinner together at the university. I was actually surprised at that kind of sense of community that... For you, is that fun or stifling? Oh, no, I like it. I mean, I appreciate it. But like, do you do it. Are you there singing? I don't go to the singing. So it's siphling. But the other thing...

That was my first surprise. The second thing that surprised me was how committed Danes were as drinkers. I'm shocked that these are the things that surprised you. And so in the town I'm in, there's actually a pub that opens at 10 at night and stays open until 8 a.m. in the morning. And Danes are not the most talkative people in the world. My thought is, what are they doing all night at this pub? And so, as I say, I was just surprised at that because I think of, you know, in other respects, by the way, Danes are super healthy. Their gyms are open all hours.

There are people in there exercising all the time. And they do very well. So I was surprised, though, at how much they drank. And then secondly, at their kind of residing sense of community. And so they have laws in Denmark, for example, try to prevent Germans from actually buying seaside property. in towns where you actually have to live in the property all year. And so I appreciate, you know, I come from Scotland. And so I appreciate the kind of the problems of kind of small societies trying to still remain

kind of culturally distinct in this modern world. How optimistic are you about Scotland today? I actually, I've seen the data. And the north of England is in terrible shape. But interestingly, Scotland is doing much better. And one of the things is what's interesting about Scottish society is when I go back there now, I seem to them completely like an American, but I meet all kinds of people who are completely non-Scottish in origin who have become culturally, completely Scottish.

And so my niece got married there to a guy who's Chinese and his best man was Vietnamese, and they were all dressed in kilts and they had bagpites playing. And so culturally, it's amazing that they're. people, you know, the culture kind of continues in Scotland, and in economic terms, Scotland is actually doing pretty well. And so as I say, it's not... But there's big subsidies, right, from the south of England. Without those subsidies, what's per capita GDP there? Well, I mean, I did say that when Scotland was becoming, considering independence, this would be like a parasite detaching itself from the host.

Yeah. Because in order to keep Scotland within the UK, They have been paying out these very generous subsidies. So, for example, in Scotland, university education is free. In England, you have to pay for this. And Scottish universities then actually have to charge English students for their education or else the English would be flooding across the borders into Scotland. But it turns out under the EU, the Germans could go for free because the EU treaties actually said,

You can't discriminate against people from other countries, but you can discriminate from people within your own country. But my hope is that Scotland will remain part of the UK and will continue to draw subsidies from the UK Treasury. And as it, it seems to be doing fine. Why are public health indicators so bad in and around Glasgow? Like, there's some of the worst in the developed world, maybe the very worst. So this actually was interesting. When I was writing my second book, I wanted to illustrate. this with a picture, because Glasgow has some of the lowest life expectancy of anywhere in Western Europe,

some parts of Glasgow, within a few miles of where I lived in Glasgow. And so I thought, oh, that's fine. I'll go to Google Earth and I'll get a picture of the squalor of Glasgow. And it turns out it doesn't exist. No, there's squalor in Glasgow. I've been to Glasgow. No, no. The subsidies and everything are so generous that I couldn't find genuine squalor in Glasgow. You need a New Jersey boy to take you on a tour. Not compared to California, right? And so in the end, I had to actually use this kind of slightly fake picture,

which was showed squalor, but it was because it was a building that was going to be demolished. But what was amazing is that within what is relatively decent material conditions, people live these lives, which, you know, are ones of, where, you know, terrible health conditions, lots of people unemployed. And again, it's kind of hard to understand. It can't be genetic, right?

Because it's fairly recent. So it's cultural. Culture has this big, huge influence. But there's been a lot of selective migration within the UK. And so this new book says, the growth of the south and the decline of the north is all attributable to self-selection. within Britain. And so Glasgow, where I come from, has had a huge amount of outmigration.

And out migration, I mean, it tends to be people with more talent, ability, stuff like that, are the ones who are on the move. And so, you know, what you're actually seeing, I think a lot of that is this kind of selective migration of people. Though I must say, so my sister trained as a doctor in Glasgow. And when they interviewed patients, they were actually trained to ask them, well, how much do you drink per day 10 pints? And people would say, oh, no, doctor, only six. And so, you know, it really, you know, so that in some sense you might say,

well, that's some kind of cultural hangover in terms of people's attitude to things like drinking and exercise and vegetables. What's your take then on modern Ireland? Because there's incredibly high rates about migration, and I don't just mean the potato famine. Just Irish going to Liverpool, right? America, Australia, all over, you look at Ireland today, it doesn't seem selection is that important.

Their education level is the highest in Western Europe, health indicators, income, whatever test you want to run, they just seem like normal Ireland. So selection there hasn't mattered, or what should I infer? Well, so it turns out even though I live in Scotland, all of my family is Irish. Ah, okay, now we're talking. Same year. And so I've thought about the whole selection issue. But the interesting thing is, so my co-author Neil Cummins has a paper that just came out,

I think they're just coming out, about the Irish in England, which argues that there was significant negative selection to the Irish who actually moved to England. And that the Irish within England, even over the course of 150 years, have remained a lower class in English society, particularly, those who moved to the north of England, right? And why negative selection in this hypothesis? Because the ones who are about to starve? I think one argument was the kinds of jobs that were available in the north of England

favored people who were unskilled, right? And so again, in Scotland, what were the Irish doing coming in? They were working in the steelworks, the coal mines, scrapyards, and stuff like that. I mean, it was kind of heavy industry that was attracting these migrants. And so one argument has been actually that migration out of Ireland has actually not been particularly positively selected. Now, in this new book, I do actually look at migration from England to other countries. And interestingly, so English migrants to the United States are the least positively selected. But for other countries like Australia and New Zealand, they are being positively selected.

but that's more than counterbalanced in England by immigration of skilled people into England, right? And so basically, England has constantly been refreshed by migrants from Europe who are highly skilled. The process of migration is quite complex. And so again, the question I had in Scandinavia was, look, Sweden and Denmark and Norway, not so much Denmark,

lost huge fraction of the population in the 19th century to migrate. how can these countries be so highly performing now, right? But again, it turns out the evidence is that migration was actually negatively selected in Scandinavian. If I go to North Dakota, which is full of Scandinavians, they're doing fine. Their indicators are great. They sort of look, feel, and act a bit like actual Nordics demographically. It doesn't feel like negative selection. It turns out, so again in the book, The Sun also rises.

You can examine, just looking at surnames, different groups within U.S. society, and basically all kind of European groups within the United States look very average, right? And so I think what was happening was that there wasn't really particularly strong selective pressures on migrations out of Europe. You do see that people who came from Quebec, French speakers from Quebec, are an underclass in the United States. and that somehow there was some kind of negative selection of people from that background. But basically, Europeans in the United States now are very much, people of European descent are very much average, right? And then the new elites in the United States are Chinese, particularly Indians, the Jewish population,

stuff like that, where there is clearly some kind of very strong positive selection going on. But it seems like the 19th century migration was not. so selective. And so my sense for Ireland would be whatever the forces of driving migration in Ireland were, maybe it actually was either neutral or even negatively selected some of the immigration from Ireland. Do you have a sense for Latin America? I unfortunately don't know. I know a different set of them go to Spain than to the U.S. I'm not sure how it all pans out. If you look at migrants from Latin America, to the United States, the further way the country is from the U.S., the better they tend to do.

And so the more positively selected, they tend to be. But the distance from Equator growth hypothesis predicts that, too, right? Oh, right. That would also be, yes. So I think it tends to be, if you're coming from places like Chile, or something like that, coming to the United States, I think it tends to be quite strongly, positively selected, yeah. Before we move to questions, I'll just note, Greg, is in the process of producing a new book. I believe the title is, for whom the bell curve tolls, genetics and social life in England, 1600 to 2025, before I turn over to the crowd.

Would you like to just say a few words about your next book? I know you've covered some parts of it already. Yeah, so the next book has been, unfortunately, 10 years in production because it depends on assembling this very big database, a detailed genealogy of people over 300 years in England. and I was really kind of motivated by this question of, to what extent does genetics actually determine social outcomes? And this book does a detailed study of all the predictions of a genetic model, right?

And so it looks at things like, does birth order matter? Does gender matter? Does your mother better predict your outcomes compared to your father? Does family size matter? if your parents die, does that influence your life course? What about your grandparents? Can they direct? And the conclusion in all of these studies is we're mainly the product of our genetics and randomness.

And randomness is a huge component as well. But, and that's why I say, amazingly, we seemed to, in Sightly like England, for 300 years, have largely lived in a meritocracy. because what would be the characteristics of meritocracy? It would be a society where genetics and randomness would be the only forces that really mattered. And so that's what the new book then is all about. And one message to this is, don't spend a lot of time with your children.

It doesn't matter. Greg Clark. Thank you very much. For questions, there is the mic. Please do not block the camera. And first question. Yes, please. I have a number of questions, but I can constrict the, I'll start with the most important ones.

Your wage price series in a farewell to alms takes a very bare-bones view of what should be in the consumption basket. You know, so food, you know, housing, clothing, and then that's it, right? And so you have a very low estimate of living standards, but other more expansive, like definitions, like, like MoCures come to very large increases in income from like Time of Hastings to, beginning of the Industrial Revolution. And so I guess, like, do you have a philosophical reason for taking a very narrow construction? And are you concerned that if you took that same very narrow construction into the present day, you would arrive at clearly absurd results like we have barely improved in living standards over time? Yeah.

So this is, you know, when you construct these living standards series, you just have to look at what people actually consumed, right? And so consumption of things like books in Europe in 1400 would be 0.001 of a percent, right? And so if you were to take someone with our or Tyler's tastes, for example, and construct a cost of living index for him, it would show radical transformation occurring actually in the 15th century when books became one, 20th of their price, and books would be an important component of his living expenses. But that series is actually constructed for the average person in England. And what happens then is that you really don't see much kind of technological advance

on these types of indices in Europe, because the advances that are occurring and they're quite significant are about tiny shares of consumption. And that's just a general problem that if we wait, technological change in economic terms, there's this tyranny of the majority, which is, what are the majority want to consume? That's determining what the measured rate of technological advance would be. And so that's one argument about, again, why the Industrial Revolution seems so abrupt is that there had been a lot of earlier technological advance, but not in the commodities that the average person consumes. And what was unique about the Industrial

revolution was that finally something like clothing now gets this huge advance and that then kind of transforms the economy. So that's why that series was done that way. Next question. Thank you very much for stopping by. I was struck by your example of the, it was the Chinese fiancé that was wearing the Scottish kilt alongside his Vietnamese, one of his best men. Best man, yes. It ties into the point you made about assimilation. In your work, What factors encourage a simulation into culture into like norms of the home country versus the opposite? And do you think that's related to economic incentives or is it more about culture? Thank you.

So I'm impressed. As I say, I've studied a lot about the upper class in Britain. And when you see the history in this genealogy of these families, you have like Jewish families arriving in Britain 1800, where their descendant, becomes a bishop in the Church of England within three generations. And so you do see this, as I say, surprising kind of plasticity, but other families remaining kind of firmly Jewish, but in other ways becoming highly English. And a nice example of that is in 1685, the Huguenots were driven out of France, and they arrived in Britain. They constituted about 1% of English population at that stage. You can see them within

one or two generations completely culturally assimilating. And you can see that in the names they call their children and in the women that they married or the men that they married, right? And so you actually see, as I say, this complete kind of and rapid kind of cultural assimilation and then a movement into the elites of British society where they, amazingly, the descendants of that group are still four times more likely to go to Oxford or Cambridge than the rest of people in English society, even though culturally 200 years earlier, they lost any kind of distinctiveness. And so, as I say, I'm impressed when you see someone like Britain how rapidly that assimilation occurs, and even in my own family. So my grandfathers were both born in Ireland.

We were in Scotland as Irish Catholics. We didn't mix with Protestants. We didn't talk to Protestants. We had all kinds of weird theories about Protestants, and they're kind of joyless life. I have a brother who married a woman who's Protestant. His children now are functionally, completely Protestant, right? And so you see this kind of, even in this period, that by moving into kind of the upper class in Scotland, which is heavily Protestant, effectively you see that assimilation. And so what I am impressed is just how rapidly people can typically assimilate. into other societies, except, I think, in cases where people aren't succeeding economically and socially.

And that then becomes this barrier to assimilation. But people who are successful within new societies, it's just astonishing how plastic, as I say, the culture of different societies is. And as I say, I never thought I would go to a wedding in Scotland with people wearing kiltz, right? Because that was completely not the culture that we came from. Hello, thank you so much for coming and giving the talk. It was an honor to listen in person. I learned a lot from your research. I think I said that I really liked the example in one of your research where you used the last name Smith and how long it took for somebody named Smith to get to like places like Oxford. It was about 200 years. And I loved that research method, but also the conclusion is a bit deterministic. It's kind of how do you manage that social mobility? So I think on that, I'm a bit more on the side of Dr. Cowan, where international mobility might have a higher rate of results than the examples in your research. And as far as I know, the research is mostly from the Anglo world within mobility within Anglo world or Europe to Anglo and the other ways around. And we use the example of India. And I think the caste system is unique to there. But what about the countries that are similar? in terms of base of living standard.

I'm from Bangladesh, like places like Bangladesh or Sri Lanka or also in recent research in immigration we see in the United States. Immigrants from MENA region are very successful. So do you think if we change the directions of migration and basis of living standard from this donor countries, will the results look more optimistic? And the second part of the question is there is research done by Johannes Haushofer, also a Nordic economist, and he has a project where he takes students from Uganda, so we can get around the pre-selection problem, and he funds them to come to Germany to study.

So maybe policy prescription-wise, do you see some benefits in this kind of solution to get out of that deterministic trap? Thank you. So let me talk first about the determinism trap. And so there's a fundamental kind of philosophical issue here, which is I, you know, I've spent a lot of time in economics, and economics really is a dismal science in the sense of how little economics has achieved, right? And how little we can predict about economies or about the future of economies. And so one of the stunning things about social mobility is how deterministic at the group level that this is. and how in the English data, you can predict what will happen to people 300 years later, based on their position now, right?

And I think of that as a kind of stunning kind of gain, right? Maybe unlike Tyler here. And I think of that as the only path forward. And as I say, what I was stunned by was in terms of social mobility, how much mechanical deterministic structure you had in societies, right? Now, I secondly agree that people moving between societies is an enormous source of economic gains and economic mobility. The relative position, though, seems to very substantially move with people when they move across societies. And I agree that it also has these very important policy things that we have to think of, which is, if America takes in more immigrants, it will benefit the world at no cost, right? And so that, you know, a lot of substantial gains will be made by moving people around in the modern world.

And that that's something we should think about in terms of thinking about policy in different countries. And so I agree there that, you know, that substantively there's not a lot you can do within a society to change people's relative outcomes. But there is a lot you can do for people by moving them from one society to another. and that that's the area then that we should think about in terms of economic policy. Thanks a lot. Thank you. I have some related questions on how you're measuring the social persistence. So the persistence of social status is the rank-rank correlation over time, which means that if there is error in measuring the status of somebody,

it tends to increase social mobility because there's less correlation. So are you concerned that the degree of error has changed, over time such that it's higher in the 1800s, for example, than compared to today as some like recent work on American inequality as demonstrated. And secondly, when people are added to the population through immigration, if they're, for example, say at all at the bottom, then it would tend to bias people's social mobility upwards because now it's a, there's different people in the mix. So how do you account for that and how do your methods avoid this? Right. So it turns out a lot of the new book, there's a whole section

which says people have not thought about errors enough in terms of measuring social mobility. And so one classic thing is people typically if you go to Scandinavia, the income correlation between parents and children or the

years of education correlation between parents and children is low implying that these are very high mobility societies. And the problem is that the errors involved in these measures. So measuring someone's education level by years of education is a very crude approximation, right? And it really tells you relatively little, particularly in a

society like Denmark where there's enormous access to education and huge subsidies of education. And so a lot of the book is saying, how do we correct for these errors? And it turns out that's what happens when you do correct for these errors. What you find is much, much more. much lower rates of social mobility, and also that it doesn't vary between Scandinavia and England now or England in the 18th century. And I think, you know, in social mobility studies, that any kind of report that isn't taking into account that all of these are very partial and imperfect measures is just not telling you a lot about the true nature of social mobility. And so that was the first point.

The second point was, well, what about admixtures within populations and how that would influence measures of social mobility? Fortunately, for most of these societies, these would tend to be relatively small changes because it's a small share of the population in any generation that is now coming anew. But you do see now in England kind of dramatic transformation where the white British now are the lower class of English society. There's emerging and very substantial new upper classes, which are Africans, Bangladeshis, Pakistanis, and particularly Hindu, Indians and Chinese. And as I say, it's an amazing kind of transformation of a society by immigration. And because of fertility differences where immigrants tend to have much higher rates of fertility, a very substantial fraction of 15-year-olds now in a society like England are fraudulent.

from these other origins, but actually it's been an enormous benefit to English society. But it would have influenced things like trying to calculate social mobility rates when you have all of these new groups kind of arriving in the society and actually being very successful. But I agree. But that's actually really very much a phenomenon of post-1960 or something like that in Britain. Thank you, Professor Clark. It was a lot of fun. What do you think are the practical implications of your work for finding a a spouse in the modern world.

I'm not sure what to advise you. I could tell you that I met my wife when we were both graduate students at Harvard. I was the first man she met at Harvard. So maybe she wasn't particularly selective in terms of... I mean, what can you say? I mean, you see a general path. pattern. Do we know that that pattern makes people happy? Maybe everyone with highly assortative marriage is actually unhappy. And if instead they had chosen a spouse on grounds of romance or something

else like that, they would be much better off. So I can't give you any advice on marriage. All I can do is say I can predict the kind of person that you're going to marry. Thank you. I wanted to ask about an ongoing debate between James Heckman and Raj Chetty on the role of neighborhoods versus family composition. So James Heckman believes, okay, family composition really matters. Listening to this talk, you'd say, maybe not. And then Chetty says that neighborhoods really matter. And I'm wondering if you take stands on these things, since it seems that there is considerable variation at the neighborhood level. But then I'm told at the national level, it all balances out. So there's no variation over time. I mean, what a coincidence this would be in social science.

So I just wanted to hear your thoughts on some of these technical recent matters. Thank you. Yeah. So there is a chapter in the new manuscript which examines exactly this issue about doesn't matter what place you're born to in England. Because as I say, the North is much less successful on every dimension, education, output, whether people are employed or not, health, longevity. It's bad somehow to be born in the North.

But with this kind of comprehensive genealogical database, we know all about everyone's parents and stuff like that. And I can tell you that there's actually very little cost to being born in the North, right? It's mostly still predicted, overwhelmingly predicted from the status of your parents. And it just turns out there are many more high status people in the south of England. Now, one puzzle is this movement to the south of England of higher status people has been gone on since the 18th century. And I don't actually understand why did everyone want to move to the areas around London and the south of England from such an early date in Britain? So even in the Industrial Revolution period, the balance of migration is of skilled people out of the north and to the south. And the migrants from the south to the north tended to be much less skilled.

And so basically the story for England is there is this kind of process of selection. And it turns out that that interestingly also occurs in other parts of Europe. And it's amazing now with, you know, modern markets and stuff like that, that in almost every place in Europe, you'll find high-income areas and low-income areas and kind of endogenously developing. But as I say, as far as we can tell from this British data, there isn't that much cost. So I was born in a mining village in Scotland. I like to think I escaped my background, but, you know, empirically, the average person born in that mining village is going to do pretty poorly.

But there is this question, is it all just about family background, or is it about the opportunities that people get offered? How do you, if I believe your chosen mechanism for it transmitting over time to be, in fact, genetics, how do you reconcile the very low estimates of heritability, from genome-wide association studies with the much higher estimates that come from twin studies. Well, these genome-wide studies, amazingly, even with something like, now is it, up to 4 million people

that they have genotype where they have measures of their educational outcomes still don't identify that, well, what the genetic basis of this is, that we know exists from these twin studies. And in some sense, what it's saying is these studies are still, we still have very imperfect measures,

even though they're identifying a thousand different loci on the genome that are affecting educational outcomes, we're still somehow not capturing everything that's happening here. And they've also studied whether it's combinatoric effects that really matter, but I think they've largely been ruled out that it's mostly just the additive impact of what's happening at each particular location. And so all I can say is that, I mean, it has this weird implication that you may need studies that are bigger than the whole of humanity to actually finally

figure out what are all these genetic influences because there are such rare kind of permutations that are actually affecting outcomes. And it also actually surprisingly means that if you have very small populations, say Native Americans, that you might not be able to do these kind of studies because you wouldn't have enough people to actually be able to say very much about, say, genetic basis of illnesses or the genetic basis of height and other things like that. But it is a puzzle in that literature, which is that even with this amount of data, and even though knowing that there is this genetic basis that is quite strong, they still cannot actually find mechanically what the location of that basis is.

Greg Clark, thank you again. We can for Greg. Thank you. Thanks for listening to Conversations with Tyler. You can subscribe to the show on Apple Podcasts, Spotify, or your favorite podcast app. If you like this podcast, please consider giving us a rating and leaving a review. This helps other listeners find the show. On Twitter, I'm at Tyler Cowen, and the show is at Cowan Convo's.

Until next time, please keep listening and learning.