From the New York Times, Aug. 7, 2007:
For thousands of years, most people on earth lived in abject poverty, first as hunters and gatherers, then as peasants or laborers. But with the Industrial Revolution, some societies traded this ancient poverty for amazing affluence.
Historians and economists have long struggled to understand how this transition occurred and why it took place only in some countries. A scholar who has spent the last 20 years scanning medieval English archives has now emerged with startling answers for both questions.
Gregory Clark, an economic historian at the University of California, Davis, believes that the Industrial Revolution — the surge in economic growth that occurred first in England around 1800 — occurred because of a change in the nature of the human population. The change was one in which people gradually developed the strange new behaviors required to make a modern economy work. The middle-class values of nonviolence, literacy, long working hours and a willingness to save emerged only recently in human history, Dr. Clark argues.
Because they grew more common in the centuries before 1800, whether by cultural transmission or evolutionary adaptation, the English population at last became productive enough to escape from poverty, followed quickly by other countries with the same long agrarian past.
Dr. Clark’s ideas have been circulating in articles and manuscripts for several years and are to be published as a book next month, “A Farewell to Alms” (Princeton University Press). Economic historians have high praise for his thesis, though many disagree with parts of it.
“This is a great book and deserves attention,” said Philip Hoffman, a historian at the California Institute of Technology. He described it as “delightfully provocative” and a “real challenge” to the prevailing school of thought that it is institutions that shape economic history.
Samuel Bowles, an economist who studies cultural evolution at the Santa Fe Institute, said Dr. Clark’s work was “great historical sociology and, unlike the sociology of the past, is informed by modern economic theory.”
The basis of Dr. Clark’s work is his recovery of data from which he can reconstruct many features of the English economy from 1200 to 1800. From this data, he shows, far more clearly than has been possible before, that the economy was locked in a Malthusian trap — each time new technology increased the efficiency of production a little, the population grew, the extra mouths ate up the surplus, and average income fell back to its former level.
This income was pitifully low in terms of the amount of wheat it could buy. By 1790, the average person’s consumption in England was still just 2,322 calories a day, with the poor eating a mere 1,508. Living hunter-gatherer societies enjoy diets of 2,300 calories or more.
“Primitive man ate well compared with one of the richest societies in the world in 1800,” Dr. Clark observes.
The tendency of population to grow faster than the food supply, keeping most people at the edge of starvation, was described by Thomas Malthus in a 1798 book, “An Essay on the Principle of Population.” This Malthusian trap, Dr. Clark’s data show, governed the English economy from 1200 until the Industrial Revolution and has in his view probably constrained humankind throughout its existence. The only respite was during disasters like the Black Death, when population plummeted, and for several generations the survivors had more to eat.
Malthus’s book is well known because it gave Darwin the idea of natural selection. Reading of the struggle for existence that Malthus predicted, Darwin wrote in his autobiography, “It at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. ... Here then I had at last got a theory by which to work.”
Given that the English economy operated under Malthusian constraints, might it not have responded in some way to the forces of natural selection that Darwin had divined would flourish in such conditions? Dr. Clark started to wonder whether natural selection had indeed changed the nature of the population in some way and, if so, whether this might be the missing explanation for the Industrial Revolution.
The Industrial Revolution, the first escape from the Malthusian trap, occurred when the efficiency of production at last accelerated, growing fast enough to outpace population growth and allow average incomes to rise. Many explanations have been offered for this spurt in efficiency, some economic and some political, but none is fully satisfactory, historians say.
Dr. Clark’s first thought was that the population might have evolved greater resistance to disease. The idea came from Jared Diamond’s book “Guns, Germs and Steel,” which argues that Europeans were able to conquer other nations in part because of their greater immunity to disease.
In support of the disease-resistance idea, cities like London were so filthy and disease ridden that a third of their populations died off every generation, and the losses were restored by immigrants from the countryside. That suggested to Dr. Clark that the surviving population of England might be the descendants of peasants.
A way to test the idea, he realized, was through analysis of ancient wills, which might reveal a connection between wealth and the number of progeny. The wills did that, but in quite the opposite direction to what he had expected.
Generation after generation, the rich had more surviving children than the poor, his research showed. That meant there must have been constant downward social mobility as the poor failed to reproduce themselves and the progeny of the rich took over their occupations. “The modern population of the English is largely descended from the economic upper classes of the Middle Ages,” he concluded.
As the progeny of the rich pervaded all levels of society, Dr. Clark considered, the behaviors that made for wealth could have spread with them. He has documented that several aspects of what might now be called middle-class values changed significantly from the days of hunter gatherer societies to 1800. Work hours increased, literacy and numeracy rose, and the level of interpersonal violence dropped.
Another significant change in behavior, Dr. Clark argues, was an increase in people’s preference for saving over instant consumption, which he sees reflected in the steady decline in interest rates from 1200 to 1800.
“Thrift, prudence, negotiation and hard work were becoming values for communities that previously had been spendthrift, impulsive, violent and leisure loving,” Dr. Clark writes.
Around 1790, a steady upward trend in production efficiency first emerges in the English economy. It was this significant acceleration in the rate of productivity growth that at last made possible England’s escape from the Malthusian trap and the emergence of the Industrial Revolution.....
....MUCH MORE
“Thrift,
prudence, negotiation and hard work"? Ha! That'll be the day.
There was also some dissension among the quoted experts:
....Most historians have assumed that evolutionary change is too gradual to have affected human populations in the historical period. But geneticists, with information from the human genome now at their disposal, have begun to detect ever more recent instances of human evolutionary change like the spread of lactose tolerance in cattle-raising people of northern Europe just 5,000 years ago. A study in the current American Journal of Human Genetics finds evidence of natural selection at work in the population of Puerto Rico since 1513. So historians are likely to be more enthusiastic about the medieval economic data and elaborate time series that Dr. Clark has reconstructed than about his suggestion that people adapted to the Malthusian constraints of an agrarian society.
“He deserves kudos for assembling all this data,” said Dr. Hoffman, the Caltech historian, “but I don’t agree with his underlying argument.”
The decline in English interest rates, for example, could have been caused by the state’s providing better domestic security and enforcing property rights, Dr. Hoffman said, not by a change in people’s willingness to save, as Dr. Clark asserts.
The natural-selection part of Dr. Clark’s argument “is significantly weaker, and maybe just not necessary, if you can trace the changes in the institutions,” said Kenneth L. Pomeranz, a historian at the University of California, Irvine. In a recent book, “The Great Divergence,” Dr. Pomeranz argues that tapping new sources of energy like coal and bringing new land into cultivation, as in the North American colonies, were the productivity advances that pushed the old agrarian economies out of their Malthusian constraints.
Robert P. Brenner, a historian at the University of California, Los Angeles, said although there was no satisfactory explanation at present for why economic growth took off in Europe around 1800, he believed that institutional explanations would provide the answer and that Dr. Clark’s idea of genes for capitalist behavior was “quite a speculative leap.”
Dr. Bowles, the Santa Fe economist, said he was “not averse to the idea” that genetic transmission of capitalist values is important, but that the evidence for it was not yet there. “It’s just that we don’t have any idea what it is, and everything we look at ends up being awfully small,” he said. Tests of most social behaviors show they are very weakly heritable....
