Cities are complicated beasts and it is very hard to compare one to another, even if that provides fodder for endless debates. But sometimes basic factors can determine why life in one city is more likely to be better than in another. Something as simple as the shape of the city, for example.
Research by the Massachusetts Institute of Technology’s Mariaflava Harari, who looked at 457 Indian cities based on their layouts, comes to the conclusion that circular cities charge a premium on their inhabitants because they are easier to commute through. Measuring how compact a city is – essentially determining how close to a circle the shape is – Harari concludes that there is a correlation between the layout and how much you pay as well as get paid.
“Cities with more compact shapes are characterized by larger population, lower wages, and higher housing rents, consistent with compact shape being a consumption amenity,” says the study titled "Cities in Bad Shape: Urban Geometry in India".
To carry out her research, Harari combined historic maps of hundreds of Indian cities with a satellite-derived dataset of night-time lights. By using satellite imagery of lights, the research avoids having to go by the official borders delineated by authorities and uses instead a more realistic image of what the city’s sprawl actual looks like.
Based on this measure, she concludes that more compact, circular cities like Bangalore have a higher population density and lower commute times since the distance to the “centre” of the city is smaller. Comparing this to wages and rents, Harari finds that residents of circular cities are actually paying for their shorter commute times.
“There is suggestive evidence that households are paying for compact geometry both through higher housing prices and through lower wages,” the paper says. “Using these estimates in conjunction with a simple version of the Rosen-Roback model, that one standard deviation deterioration in city shape entails a welfare loss equivalent to a 5% decrease in income.”
This has other impacts as well. Longer cities, like Mumbai or Kolkata, are more likely to have denser road networks as a way of addressing their commuting problems. They are also less likely to have as many slum dwellers.
“Cities with poorer shapes are characterized by comparatively fewer slum dwellers and houses of better quality,” it says. “This is consistent with the interpretation that low-income immigrants tend to sort into more compact cities, possibly because they are less able to cope with lengthy commutes.”
Harari’s terminology actually considers compact cities “better” than long ones, which are described as having “poor shape”, primarily because of the challenges they afford to urban transport and commuting costs. By that measure, Bangalore actually has the “best” shape and Kolkata has the “worst”.
“If Kolkata had the same compact shape that Bangalore has, the average trip to the center would be shorter by 4.5 km and the average trip within the city would be shorter by 6.2 km,” the study concludes. Considering the Ministry of Urban Development estimates commute speeds in metros to have been 12 km per hour in 2011, going down to 9 km by 2021, that could mean differences of up to 30 minutes in average trip times within cities depending on their shape.
But this ease of travel becomes an amenity, just like better roads or subway lines, that people in circular cities pay for with higher rents and lower wages.
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Research by the Massachusetts Institute of Technology’s Mariaflava Harari, who looked at 457 Indian cities based on their layouts, comes to the conclusion that circular cities charge a premium on their inhabitants because they are easier to commute through. Measuring how compact a city is – essentially determining how close to a circle the shape is – Harari concludes that there is a correlation between the layout and how much you pay as well as get paid.
“Cities with more compact shapes are characterized by larger population, lower wages, and higher housing rents, consistent with compact shape being a consumption amenity,” says the study titled "Cities in Bad Shape: Urban Geometry in India".
To carry out her research, Harari combined historic maps of hundreds of Indian cities with a satellite-derived dataset of night-time lights. By using satellite imagery of lights, the research avoids having to go by the official borders delineated by authorities and uses instead a more realistic image of what the city’s sprawl actual looks like.
Based on this measure, she concludes that more compact, circular cities like Bangalore have a higher population density and lower commute times since the distance to the “centre” of the city is smaller. Comparing this to wages and rents, Harari finds that residents of circular cities are actually paying for their shorter commute times.
“There is suggestive evidence that households are paying for compact geometry both through higher housing prices and through lower wages,” the paper says. “Using these estimates in conjunction with a simple version of the Rosen-Roback model, that one standard deviation deterioration in city shape entails a welfare loss equivalent to a 5% decrease in income.”
This has other impacts as well. Longer cities, like Mumbai or Kolkata, are more likely to have denser road networks as a way of addressing their commuting problems. They are also less likely to have as many slum dwellers.
“Cities with poorer shapes are characterized by comparatively fewer slum dwellers and houses of better quality,” it says. “This is consistent with the interpretation that low-income immigrants tend to sort into more compact cities, possibly because they are less able to cope with lengthy commutes.”
Harari’s terminology actually considers compact cities “better” than long ones, which are described as having “poor shape”, primarily because of the challenges they afford to urban transport and commuting costs. By that measure, Bangalore actually has the “best” shape and Kolkata has the “worst”.
“If Kolkata had the same compact shape that Bangalore has, the average trip to the center would be shorter by 4.5 km and the average trip within the city would be shorter by 6.2 km,” the study concludes. Considering the Ministry of Urban Development estimates commute speeds in metros to have been 12 km per hour in 2011, going down to 9 km by 2021, that could mean differences of up to 30 minutes in average trip times within cities depending on their shape.
But this ease of travel becomes an amenity, just like better roads or subway lines, that people in circular cities pay for with higher rents and lower wages.
