The EconomistAugust 1st 2020 Books & arts 691I
n the decadesafter the Industrial Revolution cities
choked with dirt. Charles Dickens, the great chroni-
cler of the hardships of early modern life, wrote in “Oli-
ver Twist” of a slum in Bermondsey, in south London,
that consisted of “rooms so small, so filthy, so con-
fined, that the air would seem too tainted even for the
dirt and squalor which they shelter”. It contained, he
continued, “every repulsive lineament of poverty, ev-
ery loathsome indication of filth, rot, and garbage”.
Today London is a powerhouse. When not besieged
by covid-19, its gleaming skyscrapers contain floors of
high-income knowledge workers. Its economy ac-
counts for roughly a quarter of British output. Partly
thanks to such riches, its residents and those in its
commuter belt live longer than those anywhere else in
Britain. In Bermondsey the slums have long been re-
placed with barista coffee shops and art galleries.
London resembles most other cities in the
world—in which people, activity and innovation are
increasingly concentrated. Two millennia ago, real in-
comes across much of the world, such as they were,
stood between perhaps $1,000 and $1,500 or so in to-
day’s money. Incomes in advanced economies are now
20 times that or more. High incomes are the conse-
quence of decades of compounding economic growth,
a process in which urbanisation has played a funda-
mental role. By crowding people together cities have
long been humanity’s best means of creating large
markets and gathering places where people come to-
gether to exchange ideas; from the Lyceum of Athens to
the startup incubators of Silicon Valley.
But whenever people have come together to swap
goods and ideas, the exchange of germs has inevitablyoccurred, too. Indeed, for a time the progress of the in-
dustrialising world seemed threatened by the kind of
filth that Dickens described. In order to unleash the
economic power of humankind, a revolution was re-
quired in the way that people live and how they inter-
act with others. To become rich people had to learn
how to clean up themselves and their cities. The story
of economic growth is in large part a tale of the evolu-
tion of hygiene.
The Roman Empire, which had high levels of urban-
isation, was repeatedly ravaged by pandemics. These
occasionally threatened to topple the state: including,
in the 6th centuryce, the first major outbreak of bu-
bonic plague, which killed as many as 30m people.
When the plague again roamed across Eurasia eight
centuries later, claiming the lives of between 30% and
60% of Europeans, it once more followed traders from
city to city. People in the 14th century had no knowl-
edge of the microscopic world around them. Illness
was commonly viewed as a matter of bad fortune or di-
vine retribution.
Even so, the progression of the bubonic plague
from settlement to settlement was obvious enough to
make people aware of the threat of contagion. Commu-
nities began taking some of the first steps toward pre-
serving public health by closing themselves off to for-
eigners or otherwise limiting access to their towns. It
was this second plague epidemic, which began in 1348
and raged intermittently for five centuries, which gave
the world the word quarantine, from the Venetian
word quarantena, or “40 days”: the amount of time ar-
riving ships were required to sit in isolation before
passengers could come ashore.WASHINGTON, DC
The history of economic expansion is partly a history of hand-washingHygieneCleanliness is next to growth
Perspectives is
an occasional
series in which our
correspondents
put the pandemic
in context