http://www.nytimes.com/2007/08/07/science/07indu.html?_r=1&emc=eta1&oref=slogin New York Times
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.
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
“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
Given that the English economy operated under Malthusian
constraints, might it not have responded in some way to the forces of natural
selection that
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
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
In the rest of
It is puzzling that the Industrial Revolution did not occur first
in the much larger populations of
After the Industrial
Revolution, the gap in living standards between the richest and the poorest
countries started to accelerate, from a wealth disparity of about 4 to 1 in 1800
to more than 50 to 1 today. Just as there is no agreed explanation for the
Industrial Revolution, economists cannot account well for the divergence between
rich and poor nations or they would have better remedies to offer.
Many commentators point
to a failure of political and social institutions as the reason that poor
countries remain poor. But the proposed medicine of institutional reform “has
failed repeatedly to cure the patient,” Dr. Clark writes. He likens the “cult
centers” of the
World Bank and
International Monetary Fund to prescientific
physicians who prescribed bloodletting for ailments they did not understand.
If the Industrial
Revolution was caused by changes in people’s behavior, then populations that
have not had time to adapt to the Malthusian constraints of agrarian economies
will not be able to achieve the same production efficiencies, his thesis
implies.
Dr. Clark says the
middle-class values needed for productivity could have been transmitted either
culturally or genetically. But in some passages, he seems to lean toward
evolution as the explanation. “Through the long agrarian passage leading up to
the Industrial Revolution, man was becoming biologically more adapted to the
modern economic world,” he writes. And, “The triumph of capitalism in the modern
world thus may lie as much in our genes as in ideology or rationality.”
What was being
inherited, in his view, was not greater intelligence — being a hunter in a
foraging society requires considerably greater skill than the repetitive actions
of an agricultural laborer. Rather, it was “a repertoire of skills and
dispositions that were very different from those of the pre-agrarian world.”
Reaction to Dr. Clark’s
thesis from other economic historians seems largely favorable, although few
agree with all of it, and many are skeptical of the most novel part, his
suggestion that evolutionary change is a factor to be considered in history.
Historians used to
accept changes in people’s behavior as an explanation for economic events, like
Max Weber’s thesis linking the rise of capitalism with Protestantism. But most
have now swung to the economists’ view that all people are alike and will
respond in the same way to the same incentives. Hence they seek to explain
events like the Industrial Revolution in terms of changes in institutions, not
people.
Dr. Clark’s view is
that institutions and incentives have been much the same all along and explain
very little, which is why there is so little agreement on the causes of the
Industrial Revolution. In saying the answer lies in people’s behavior, he is
asking his fellow economic historians to revert to a type of explanation they
had mostly abandoned and in addition is evoking an idea that historians seldom
consider as an explanatory variable, that of evolution.
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
“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
Robert P. Brenner, a historian at the
Dr. Bowles, the
He also took issue with
Dr. Clark’s suggestion that the unwillingness to postpone consumption, called
time preference by economists, had changed in people over the centuries. “If I
were as poor as the people who take out payday loans, I might also have a high
time preference,” he said.
Dr. Clark said he set out to write his book 12 years ago on
discovering that his undergraduates knew nothing about the history of “The actual data underlying this stuff is hard to dispute,” Dr. Clark said. “When people see the logic, they say ‘I don’t necessarily believe it, but it’s hard to dismiss.’ ” |