The intricate geometry of cities

The intricate geometry of cities

The smart talk is all about smart cities these days. There is less discussion about the shape our cities have taken. Most just assume that the city resembles a circle or star.

Urbanists have for long been divided between those who believe cities develop organically and those who argue for detailed city planning. Almost all of them agree the economic development of a country depends on the fortunes of its cities. It is welcome that India is becoming an increasingly urban nation. The 2011 census reported that 31% of the population now lives in urban areas. That masks the nuanced fact that many states have urbanized at a rapid pace.

One stark example of the slapdash nature of urban growth was provided by Partha Mukhopadhyay, a senior fellow of the Centre for Policy Research, as reported in a series published in Mint. He spoke about the problems in a government-run housing project.

In Delhi, about 20,000 apartments are vacant because they cant find people to move in there. People are not moving in for two reasons. First, because, they are built in places where they dont have services that enable people to use it productivelythere is no infrastructure of water, power, transport, etc. And second, in terms of governance, the city of Delhi has no idea which 20,000 it will take to put there. Nobody wants to voluntarily go there.

So, while smart cities have become the buzzword in urban policy, there is still little that we know about how cities evolve. The government is unclear about what exactly a smart city would look like. Policymakers need insights into how urban centres have developed over the last few decades in India. There is now new evidence that can help them understand the dynamics of the Indian urban economy.

A recent paper by Mariaflavia Harari, a PhD student at the Massachusetts Institute of Technology, throws some fresh light on the economic implications of the geometry of a city. Harari has studied the shapes of 450 Indian cities. Based on her analysis, she says, All else being equal, including city size, a city with a more compact geometry is characterized by shorter within-city trips. A compact urban geometry is essentially about how closely it resembles a circle.

Why should we care about commuting? Based on the 2009 data from the National Sample Survey Organization, Ajay Sharma of the Indian Institute of Management, Indore, and S. Chandrasekhar of the Indira Gandhi Institute of Development Research estimate that close to 13% of the Indian workforce commutes to cities every day and that those rural households that commute are better-off than those who do not.

The commuters have higher monthly per capita spending as well as greater dietary diversity. This number is likely to grow even more given the NDA governments emphasis on expanding infrastructure projects and promoting manufacturing industries.

How should one then measure the evolution of cities in India? The lack of quality official data at disaggregated levels has forced economists to use alternatives. In 2012, economists Vernon Henderson, Adam Storeygard and David Weil of Brown University said that examining night-time light data could be a useful way to understand economic activity. Using data for 188 countries, Henderson and his colleagues showed luminosity as a proxy for economic activity could substitute for gross domestic product data, particularly in developing countries, where data quality is often a problem.

Using this particular data set, Harari constructed a measure of city shape and said a city with a compact shape is likely to be associated with lower commuting time. This idea of looking at residential choice draws on the seminal work of Jennifer Roback, a senior fellow at the Acton Institute, and Sherwin Rosen of the University of Chicago. Their framework is known as the Rosen-Roback model.

Both worked independently to come up with a simple model explaining why different cities are characterized by different wages, prices and housing costs. According to the Rosen-Roback model, people will choose to locate to a city based on the wages and commuting costs involved. Harari extends this simple relationship with an added feature: urban shape. An out-of-shape city is likely to worsen the commuting time of its residents. This is why, Harari contends, it takes much longer for a Kolkata resident to move within the city than someone working in Bengaluru.

Harari suggests two specific policy responses to the sort of shapelessness that reduces welfare. First, relaxing restriction on floor area ratios (FAR) could help in managing the problem of urban sprawl. Second, urban road development could also offset the loss incurred because of poor shape. She argues, The urban transit is indeed the main channel through which non-compact shape affects consumers, and supports the interpretation of city shape as a shifter of commuting costs.

Road development in the form of the National Highways Development Project (NHDP) seems to bridge the gap in economic activity between large cities and small towns. Gaurav Khanna, a PhD student at the University of Michigan, Ann Arbor, has used night-time light as an indicator of development to show that investment in the NHDP has had spillover effectsnot only did the connected cities gain, neighbouring regions also saw a rise in economic activity.

The success of nations depends crucially on how its cities perform. Edward Glaeser, in his wonderful Triumph of City, describes this with poetic flourish:

Cities, the dense agglomerations that dot the globe, have been engines of innovation since Plato and Socrates bickered in an Athenian marketplace. The streets of Florence gave us the Renaissance, and the streets of Birmingham gave us the Industrial Revolution. The great prosperity of contemporary London and Bangalore and Tokyo comes from their ability to produce new thinking. Wandering these citieswhether down cobblestone sidewalks or grid-cutting cross streets, around roundabouts or under freewaysis to study nothing less than human progress.

Source: mint

SMART GRID Bulletin March 2017

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