West focussed on cities in his discussion of the newly discovered exponential
scaling laws that govern everything alive. “We live,” he said, “in an
exponentially expanding socio-economic universe.” Global urbanization has
reached the point that there are a million new people arriving in cities every
week, and that rate is expected to continue to midcentury. What is the
attraction?
One reason for constant urban growth is that the bigger the city, the more
efficient it is, because of economies of scale. With each doubling of a city’s
size, the numbers of gas stations and power lines and water lines, etc.
increase at a rate a little less than double. In other words, with every size
increase there is a 15% improvement in energy efficiency. “That‘s why New York
is the greenest city in America,” West said.
The same dynamics of networks explain how what is called “power-law scaling“
works in biology. The bigger the animal, the slower and more efficient its
metabolism is, at a rate lower than 1-to-1 (“sublinear” in West’s terminology).
This leads to some remarkable constants. Shrews weigh 2 grams, and in their
14-month life their heart beats a billion times. Blue whales weigh 200 million
grams, and in their 100-year life, their heart beats the same billion times.
Ditto for all mammals (except humans, who have achieved a lifetime average of 2
billion heartbeats, presumably for cultural reasons.)
In physical terms, cities are like organisms, enjoying sublinear economies of
scale with each increase in size. But when you look at cities in terms of
their social-economic networks, an astonishing finding emerges. Once again
there is power-law scaling if you count patents, wages, tax receipts, crimes,
restaurants, even the pace of walking, but instead of slowing down with
increasing size, cities speed up with increasing size. Their increase is
greater that 1:1. It is superlinear.
“Bigger cities are better,” West announced. Each time they increase in size,
they are 15% more innovative socio-economically at the same time they are 15%
more efficient in terms of energy and materials. Furthermore, they apparently
live forever. They create most of civilization’s problems, but they are
capable of solving problems even faster than they create them.
However, when you compare companies with cities, companies have similar
metabolic efficiences of scale as they grow, but their innovation rate, instead
of increasing with size, slows down as they get ever bigger. And they are
mortal. The average lifespan of publicly traded companies is 10 years. They
can grow prodigeously, but their net income, sales, profits, and assets can’t
quite keep up—they are sublinear. Successful new companies start off like
cities, full of innovation, but over time the nature of corporate growth leads
them to focus ever more solely on exploiting their success, and eventually they
taper off and die like animals.
The city feeds on their corpses and creates new companies.
—Stewart Brand
s...@longnow.org <mailto:s...@longnow.org>
[Note: A linkable version of this summary is on Medium, here
<https://medium.com/@stewartbrand/why-cities-live-forever-3cd451c0c48d>.
You’ll find video and audio versions of Goeffrey West’s talk at Long Now’s
website, here
<http://longnow.org/seminars/02017/may/23/universal-laws-growth-and-pace/>.]
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