On Geoffrey West's Density Arguments
I'm not sure how Geoffrey West managed to escape the clutches of the University of Chicago. A trained physicist, West recently wrote a major theoretical paper on biology and now he's looking at "urban science" (and corporate productivity). West attempts to tease out the major mathematical relationships governing the size of bodies.
This paragraph of the New York Times Jonah Lehrer article explains his contribution to biological theory:
The mathematical equations that West and his colleagues devised were inspired by the earlier findings of Max Kleiber. In the early 1930s, when Kleiber was a biologist working in the animal-husbandry department at the University of California at Davis, he noticed that the sprawlingly diverse animal kingdom could be characterized by a simple mathematical relationship, in which the metabolic rate of a creature is equal to its mass taken to the three-fourths power. This ubiquitous principle had some significant implications, because it showed that larger species need less energy per pound of flesh than smaller ones. For instance, while an elephant is 10,000 times the size of a guinea pig, it needs only 1,000 times as much energy. Other scientists soon found more than 70 such related laws, defined by what are known as “sublinear” equations. It doesn’t matter what the animal looks like or where it lives or how it evolved — the math almost always works.
(T)hey concluded that cities looked a lot like elephants. In city after city, the indicators of urban “metabolism,” like the number of gas stations or the total surface area of roads, showed that when a city doubles in size, it requires an increase in resources of only 85 percent.
So, cities are more efficient. But people don't move to cities to become efficient.
According to the data, whenever a city doubles in size, every measure of economic activity, from construction spending to the amount of bank deposits, increases by approximately 15 percent per capita. It doesn’t matter how big the city is; the law remains the same.
Ah, so cities are efficent and more productive. Is there a downside?
When Bettencourt and West analyzed the negative variables of urban life, like crime and disease, they discovered that the exact same mathematical equation applied. After a city doubles in size, it also experiences a 15 percent per capita increase in violent crimes, traffic and AIDS cases.
Well, those are remarkable findings which raise some interesting policy issues regarding density. Lehrer's article barely touches on the contrasting views of West and Joel Kotkin, with West basically calling the suburban landscape a tumor, while Kotkin points to the Silicon Valley and the Research Triangle as contrary data points. I welcome the introduction of more data into the density argument; otherwise, the debaters tend to simply justify their chosen lifestyles. (I know that's what I do, anyway.) In any case, we'd do well to pay attention to the data West has collected.
(Photo taken at a rock music festival in Beijing. The larger the city, the more niches that can be supported.)
Nest or cave? (1)