Misshapen Cities

Another strike against Manhattan: Henry Grabar flags new research suggesting that circular cities are superior to their elongated counterparts. He notes a paper by MIT scholar Mariaflavia Harari, who “analyzed more than 450 Indian cities to elucidate what influence, if any, a city’s shape would have on indicators like rent, wages and commute time”:

What she found is that “compactness” — in her paper, the nearer, basically, that a city’s shape is to a circle — is a kind of urban amenity, like a subway line or a Manhattan movie theater, that people will pay for. All else being equal, India’s compact cities have lower wages, higher rents and shorter commutes. “One standard deviation deterioration in city shape, corresponding to a 720 meter increase in the average within-city round-trip,” Harari writes, “entails a welfare loss equivalent to a 5 percent decrease in income.”

An instructive comparison is between Kolkota (Calcutta) and Bengaluru (Bangalore). Among the country’s largest cities, these are on opposite ends of Harari’s measurement system: giraffe-like Kolkota has the “worst” geometry, squat Bengaluru the “best.” According to Harari, “if Kolkota had the same compact shape that Bengaluru has, the average trip to the center would be shorter by 4.5 kilometers and the average trip within the city would be shorter by 6.2 km.” Just a couple of miles difference, right? But the average commute speed in India is 12 km per hour, and is forecast to fall to 9 km per hour within the decade. For the average person, on an average potential trip, compactness could save an hour a day

(Map of Manhattan via Flickr user Nick Normal)