The Economist explains

What Is An Aerotropolis?

Dec 11th 2013, 23:50 by J.F. | ATLANTA

TWO years ago John Kasarda, who teaches at the University of North Carolina's Kenan-Flagler

business school, published a book called "Aerotropolis: The Way We'll Live Next". It argues that

airports are becoming anchors for a new type of city. Traditionally, airports have been built on

urban fringes to serve pre-existing cities. Residents tend to think of them as necessary nuisances.

Getting into the city from the airport is usually arduous and expensive: think of Heathrow, on the

western edge of greater London, or O'Hare, along Chicago's northwestern fringes, connected to

its city by a narrow, annexed strip of land. These airports, and others like them, serve their cities

but are not, in any real sense, part of them. The cities were already there, and they needed

airports. So they were built somewhere outside the city, preferably surrounded by empty land, or

at least by sparsely populated areas; and residents tolerated them, but the easier it was to get in,

out and away from them, the better.

That paradigm, argues Mr Kasarda, is changing: cities are beginning to develop around airports.

This development includes not just hotels and restaurants, but also, more importantly, transport-

focused or transport-dependent businesses. "City airports," Mr Kasarda argues, are becoming

"airport cities". Consider, for example, Amsterdam Zuidas (pictured) a neighbourhood south of

that city's core but quite close to Schiphol Airport; Ekurhuleni, east of Johannesburg but adjacent

to Africa's busiest airport O.R. Tambo and bisected by the motorway linking Johannesburg and

Pretoria; and Songdo International Business District, built on land reclaimed from the Yellow

Sea just over the Grand Bridge from Incheon Airport, from which one-third of the world's

population is within a three-and-a-half-hour flight. Spatially, these places resemble traditional

cities, but with an airport rather than an urban core at their centres.

Those are planned developments. But aerotropolei can also develop organically. Memphis,

Tennessee, for instance, has branded itself "America's Aerotropolis". It was founded in the early

19th century, and prospered through the cotton and lumber trades. Today its largest employer is

Fedex, which has made the Memphis airport the world's second-busiest for cargo (for years it

was the busiest, but since 2009 has been pipped by Hong Kong). Similarly, Louisville,

Kentucky, a few hundred miles north-east of Memphis, developed as a rail and barge trans-

shipment hub. Today its biggest employer is UPS. Both have attracted dozens of shipping-

dependent companies to these once-depressed, mid-southern cities. Retailers can take orders later

and cut shipping costs by being in the middle of the country and a short drive from an express-

mail hub rather than on one of the coasts. Medical-testing companies can get blood from veins to

their labs faster, and with fewer missed samples. Mobile-phone and laptop-repair firms can have

a device fixed and turned around to its owner in hours.

In addition to express-mail companies, Memphis and Louisville both have immense geographic

advantages: they are temperate (fewer airport closures); central relative to the rest of their

continent; have river ports, freight-rail lines and multiple interstate highways, as well as

relatively low labour costs and plenty of space. Coastal or remote cities or cities subject to

extreme weather may not be able to harness airport-driven development as vigorously as

Memphis and Louisville have. On the other hand, purpose-built aerotropolei have problems of

their own: cities built to facilitate global trade will be prone to suffering when trade declines

during economic downturns. This suggests that for all of Mr Kasarda's bold, futurist predictions,

at the heart of his thesis lurks a simple fact: airports encourage growth and development, and the

land surrounding airports is often undervalued and underused.