Gregory Clark on Social Mobility, Migration, and Assortative Mating

Economic historian Gregory Clark, author of A Farewell to Alms and The Son Also Rises, defends his central claim against Tyler Cowen live at Mercatus: relative social mobility has barely changed across five centuries of English history, regardless of politics, wealth, or migration, and the underlying mechanism is closer to genetics and randomness than to culture or policy.

Key ideas

1. Relative social mobility has been essentially flat in England since medieval times. Clark argues that quintile-to-quintile Status Persistence between parents and children is no lower now than in 1300, unaffected by industrialisation, the welfare state, or 300 years of institutional change — a claim Cowen resists throughout, arguing Clark conflates relative ranking with the vastly improved absolute living standards people actually care about.
2. Physical migration transforms material welfare but leaves relative social position intact. Britons who moved to Australia, Canada, or the United States saw large gains in living standards, yet their descendants’ relative standing within the new society tracked their starting position almost exactly — a pattern Clark also finds among Hungary’s pre-Communist elite, whose descendants re-emerged into medical school admissions and, later, parliament once Communism ended.
3. Assortative mating is a stable, powerful, and probably ancient feature of British society. Using 1.7 million English marriage records from 1837 onward, Clark finds people pairing with partners as socially close to them as siblings — a pattern he can trace back only to around 1750, which he speculates may itself have helped trigger the Scientific Revolution and Industrial Revolution in Northern Europe.
4. Clark’s hereditarianism argues for more redistribution, not less. Because he holds that outcomes are largely inherited and not readily changeable by policy, he reasons a good society compresses the resulting differences rather than moralising about them — pointing to Denmark’s high taxes and strong social provision as consistent with, not opposed to, a hereditarian view.
5. India’s failure to industrialise under British rule remains, on Clark’s own account, unexplained. A talented elite (illustrated by the long-dominant Brahmin caste and today’s successful Indian diaspora) coexisted for over a century with free trade, transplanted British legal and civil institutions, and open immigration of entrepreneurs — yet not a single one of India’s 450 textile mills matched the average productivity of an English mill by 1940.

Content

Relative versus absolute mobility: the central disagreement

The episode opens on Cowen’s core objection to Clark’s whole research programme: Clark measures social mobility as the correlation between a person’s position and their parents’ position in a status distribution — a relative ranking — while Cowen wants to know whether people’s actual lives improved, an absolute standard. Clark’s answer is that relative position is what people are ‘obsessed with’, citing Britain’s fixation on which schools and which universities the political class attended. Cowen, unpersuaded, counters that Americans care about rising absolute living standards, not where they sit relative to Bill Gates. Clark’s core empirical claim survives the exchange unmoved: comparing medieval England, Denmark, and modern Britain, he finds no evidence that rates of relative social mobility have improved, even as absolute living standards have risen roughly fifteenfold since 1800. He reads this as evidence that England reached functional meritocracy — a state in which genetics and randomness, not birth, chiefly determine outcomes — by around 1700.

Migration as the exception that proves the rule

Cowen presses an alternative reading he attributes to Leo Strauss and Bryan Caplan: Clark’s own data show that social mobility is real, but the only mechanism that reliably delivers it is geographic movement, not staying in place within a fixed hierarchy. Clark agrees migration produces large material gains — Indian-American household income vastly exceeds Indian domestic income, for instance — but insists relative position survives the move almost intact. His new manuscript traces Britons who emigrated to Australia, Canada, and the United States: absolute welfare rises sharply, but a family’s relative standing in the new society closely mirrors its standing in the old one. He extends the same logic to a natural experiment under Communism: using surname analysis, he finds Hungary’s pre-Communist elite lost access to parliament under Communist rule but retained access to medical school admission throughout — and their descendants reclaimed political prominence the moment the free-market system returned. For Clark, this is evidence that relative position operates ‘in some very physics-like way’ across radically different institutional environments.

Assortative mating and its trade-off with inequality

Clark describes 1.7 million English marriage records running from 1837 to the present, which show spouses matching on social status with a precision close to sibling-level genetic similarity — far tighter than would occur from random pairing, and tighter than would result even from cousin marriage, where the pool of eligible cousins is too thin to guarantee a close match. He can trace the degree of this assortativeness back only to about 1750, and speculates it may be a distinctively Northern European ‘discovery’ of the late Middle Ages that helped propel the Scientific Revolution, the Enlightenment, and the Industrial Revolution by concentrating high ability rather than diluting it. The trade-off is explicit: assortative mating does not change a society’s average ability level, but sustained over generations it widens the distribution — producing more people at the very top (useful if growth depends on an elite 1–5 percent) at the cost of more inequality. Clark notes that highly redistributive Nordic societies have not narrowed the inequality of PISA educational scores relative to the more unequal United States, which he attributes to assortative mating remaining strong even where income is heavily compressed. A related paper with Neil Cummins, newly published in PLOS One, finds no evidence of hypergamy (women marrying up in status) in English marriage records since 1837 — matching, in Clark’s account, is driven overwhelmingly by social status on both sides.

The India puzzle and the limits of institutional explanation

Cowen and Clark spend an extended stretch on why India failed to industrialise under British rule despite a demonstrably talented elite — illustrated by the historically dominant Brahmin caste and by the outsized success of the Indian diaspora in the United States today. Clark rejects the standard explanations in turn: it was not simple British neglect (he cites the scale of Anglo-Indian entrepreneurship, the openness of British markets to migrant entrepreneurs such as the Sassoon family, and Karl Marx’s own mid-19th-century prediction that British investment would make India an industrial power); it was not managerial failure at the level of the individual factory (19th-century cotton mills required only a handful of skilled managers and were largely failure-resistant, run successfully elsewhere by low-skilled teenage labour). The starkest data point: by 1940, not one of India’s 450 textile mills matched the average productivity of an English mill. Clark calls this one of history’s great unresolved puzzles and proposes a prize for whoever can explain it. He is equally sceptical of appeals to ‘culture’ as an explanation for the India case or for South Korea’s later transformation, arguing that once an explanation becomes an untestable cultural narrative, it stops making progress — a position Cowen challenges as itself a symptom of over-narrow economic method.

Clarkian Malthusianism

Clark defends a specific and, by his own admission, idiosyncratic redefinition of Malthusianism. Against the popular association of ‘Malthusian’ with poverty, he argues the defining feature is only a positive link between fertility and living standards under a fixed resource constraint — a condition compatible with a materially rich society. Pre-industrial England after the Black Death illustrates the point: population stayed below two million for decades, yet ordinary diets included daily meat and houses that a modern Arlington resident ‘would be happy to move into’. Pre-contact Tahiti is his other example — a society with high material living standards sustained through population control by warfare and infanticide (killing between a third and half of all children born), which he still classifies as Malthusian because fertility tracked resource availability. Applied to foreign aid in sub-Saharan Africa, the Malthusian frame implies aid raises welfare directly but is partly offset by resulting population growth in agriculture-dependent economies — an argument for pairing aid with industrialisation or fertility reduction, not for withholding it.

Hereditarianism, redistribution, and Denmark

Asked to unpack his self-description as a ‘hereditarian’ (from a Quillette essay), Clark states the position plainly: if outcomes are substantially inherited and not readily changed by policy, a good society compresses the resulting inequality rather than moralising about who deserves what — a stance he finds embodied in Denmark’s combination of high taxation, heavy redistribution, and continued technological productivity. Cowen presses the opposite policy inference: if migration, not domestic reshuffling, is what actually raises welfare, Denmark’s generous welfare state and high taxes should be read as deterring the highest-quality immigrants (contrasted with the United States’ pull on elite Indian entrepreneurs), so a hereditarian who values growth should favour lower taxes and more open, market-driven immigration instead. Clark partly concedes the tension — Denmark’s own immigrants have not responded to its social contract the way native Danes have, and Danish politics is increasingly contested over exactly what kind of immigrant to admit — while defending Denmark’s model on grounds beyond growth alone: high living standards among unskilled workers, minimal visible poverty compared with California, and a strong communitarian culture he personally enjoys (weekly staff singing, an annual dinner for 4,000 university staff) even where he does not fully participate in it.

Migration, selection, and assimilation

Clark distinguishes between positively and negatively selected migration streams using surname and genealogical evidence. English emigrants to the United States were the least positively selected English emigrant group (offset by highly skilled inflows from Europe), while emigrants to Australia and New Zealand were more positively selected. Irish migration to England, per a paper by his co-author Neil Cummins, shows negative selection concentrated in heavy industry — steelworks, coal mines, scrapyards — with descendants remaining a lower social class in England for over 150 years, especially in the North. Scandinavian 19th-century emigration was also negatively selected, in Clark’s reading, even though the resulting Scandinavian-American communities (in North Dakota, for instance) appear to perform well today — a tension he does not fully resolve. On assimilation, he finds British and Scottish society strikingly ‘plastic’: Huguenot refugees of 1685 assimilated within one or two generations while retaining an enduring elite advantage (descendants still four times more likely to attend Oxford or Cambridge two centuries later); a Jewish family arriving in 1800 produced a Church of England bishop within three generations. He locates the barrier to assimilation not in origin but in economic and social failure — groups that succeed assimilate readily, in his account, while those that do not remain distinct.

Neighbourhood, family, and the limits of place

Responding to a question framing his work against the Chetty-versus-Heckman debate over neighbourhood effects versus family composition, Clark reports findings from his comprehensive English genealogical database: being born in the economically weaker North of England carries very little independent cost once a family’s existing social position is accounted for — outcomes are ‘overwhelmingly predicted’ by parental status rather than by place. What varies by region, in his account, is the concentration of high-status families, itself the product of centuries of selective internal migration toward London and the South of England dating back to the 18th century and continuing through the Industrial Revolution, when skilled workers moved south and less-skilled workers moved north. He extends this selective-migration frame to explain Glasgow’s poor health outcomes despite decent material conditions — heavy historical out-migration of the more able and ambitious, leaving a residual population with what he calls a cultural ‘hangover’ around drinking and health behaviour that outlives the original selection.

Genetics: heritability, the next book, and open questions

Closing the audience Q&A, Clark addresses the gap between the low heritability estimates from genome-wide association studies (GWAS), even at samples approaching four million genotyped individuals, and the much higher heritability estimates from twin studies — acknowledging this as a genuine, unresolved puzzle in the genetics literature, and noting the same limitation may make it difficult to study genetic effects in small populations such as Native Americans. He previews his forthcoming book, provisionally titled For Whom the Bell Curve Tolls: Genetics and Social Life in England, 1600 to 2025, ten years in the making and built on detailed multi-generational genealogy for England, testing whether birth order, gender, parental death, family size, and grandparental influence affect outcomes. His summary finding: ‘we’re mainly the product of our genetics and randomness’ — a state of affairs he equates with functioning meritocracy, and which leads him to the closing, deliberately provocative aside that parental time investment in children does not appear to matter much.

See also

• Gregory Clark — speaker
• Tyler Cowen — host
• Sheilagh Ogilvie on Epidemics, Guilds, and the Persistence of Bad Institutions — Ogilvie directly disputes Clark’s persistently-low-mobility thesis
• The Son Also Rises — Clark’s surname-based study of social mobility
• A Farewell to Alms — Clark’s earlier book on the Industrial Revolution, cited repeatedly in this conversation
• Status Persistence — the constant-relative-mobility mechanism at the episode’s centre