In Dusty Archives, a Theory of Affluence

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.
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Alan Baker
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Breaking Out of a Malthusian Trap

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.