In northern Colombia, in the unsettled outskirts of the city of Valledupar, stand parallel rows of newly planted trees, the kind you expect to see lining an important road.
Except there are no roads in sight, just the young trees. They’re leafy evidence of an urban-planning initiative that’s all too rare. With foresight, Valledupar is acquiring rights of way to build roads that it will need as it expands. The trees, which produce profuse yellow flowers in the dry season, are essentially watch-this-space advertising. It’s cheaper and easier to stake out the roads’ routes now than it will be after the sprawl occurs.
The takeaway from Valledupar is that good government matters. There are those in the rich West who romanticize the crowded, chaotic slums of megacities such as Dhaka, Lagos, Manila, and Rio de Janeiro. But we can admire the ingenuity and perseverance of slum dwellers while still trying to fix the governmental dysfunction that causes their ghastly living conditions. Laying out roads before they’re needed is precisely the kind of thing more cities should be doing.
As productive as they are, cities can be scary, especially when they seem to be growing out of control. According to the United Nations’ Population Division, as of 2011, 86 percent of the least developed countries had policies to slow rural-to-urban migration. Those policies have failed almost universally because the prospect of a better life—even a slightly better life—is irresistible. Many people perceive even bad cities as better than the alternative, which is usually subsistence agriculture. Even authoritarian China hasn’t been able to fully control the flow from the countryside.
Making cities work is vital because a little more than half the world population already lives in urban areas, and the proportion could reach 80 percent by the end of this century. The UN says there are 32 “urban agglomerations” with 10 million people or more. “These hypercities and supercities and megacities are forms of social and economic organization that we simply haven’t registered since Homo sapiens emerged,” says Robert Muggah, research director of the Igarapé Institute, based in Rio de Janeiro, which works on security and justice issues. “I’m very nervous about the ability of those parts of the world where urbanization is happening most rapidly to manage this transition,” he adds.
In 2011, the McKinsey Global Institute published an article titled “What’s the biggest limit on city growth? (Hint: it’s not steel or cement).” The binding constraint is management, it concluded. One problem is that as urban areas spread, they swallow up neighboring towns that remain outside the core cities’ jurisdiction. “Theoretically … there is no limit to the size of cities. In practice, however, the growth of most urban centers is bound by an inability to manage their size in a way that maximizes scale opportunities and minimizes costs,” wrote Richard Dobbs and Jaana Remes, senior partner and partner, respectively, at McKinsey & Co.
There was a time in the 19th century that what are today the world’s most powerful and glamorous cities were themselves almost ungovernable. New York suffered cholera epidemics in 1832, 1849, and 1866. Typhoid was endemic in Tokyo. In Paris, child prostitution was common. London’s particulate air pollution was worse than Delhi’s is today.
The rapidly growing megacities of the developing world will have a tougher time becoming magnets for global commerce and tourism. First, they’re poorer than the likes of New York and London were at the same stage of urbanization, notes Harvard economist Edward Glaeser, author of . Second, many have worse governance. Corruption and incompetence are a deadly brew for megacities already up against enormous challenges.
But change is possible. One frequently cited role model is Curitiba in southern Brazil. Jaime Lerner, who was mayor three times from the 1970s through the 1990s, came up with smart ideas such as absorbing floods by turning lowlands into vast parks instead of trying to fight nature by erecting levees. (Sheep keep the grass trimmed.) Lerner also pioneered a cheap, ubiquitous rapid-transit system based on dedicated bus lanes rather than subways. His 2014 book, , advises “probing here and there to stimulate improvements and positive chain reactions.”
What Valledupar is doing in Colombia is similarly clever. The street-planning idea was dreamed up by Shlomo “Solly” Angel, who leads the Urban Expansion program at New York University’s Marron Institute of Urban Management. It’s virtually costless because ranchers and farmers are happy to donate land that will be adjacent to a main road, Angel says. NYU has landed a contract to train 109 other Colombian cities in planning for expansion and is working with 18 cities in Ethiopia. “It is impossible to cut a road through a built-up area,” he says. “Either we do it now or we don’t do it at all.”
(Bloomberg Philanthropies grants prizes to cities that come up with solutions to urban problems; Curitiba was a finalist last year. Michael Bloomberg, former mayor of New York City, is the majority shareholder of Bloomberg LP, which owns this magazine.)
Cities will sprawl—it’s pointless to try to stop the phenomenon. To the dismay of many environmentalists and urbanists, most people dislike tight quarters. They use rising incomes to buy themselves more space. In 2015, metro Paris and metro Lagos had about the same population—11 million—but Paris occupied 3.5 times as much land, Angel says. Nothing new about this: “H.G. Wells talked about a ‘middle landscape’—you get access to the urban advantages, but you don’t have to live in a cramped space,” says Joel Kotkin, a presidential fellow at Chapman University and author of books including .
The beauty of cities—the reason Glaeser calls them “our greatest invention”—is that proximity generates creativity, as some of the stories in this special issue make clear. People brush up against others who have different worldviews and know different things. It’s an example of what Stanford sociologist Mark Granovetter, in a landmark 1973 paper, called “the strength of weak ties.” The number of these potentially useful weak ties grows “superlinearly”—i.e., even faster than the growth of the population—writes Geoffrey West, who ran high-energy physics research at Los Alamos National Laboratory and later served as president of the Santa Fe Institute, in a new book called .
If those positive scaling effects were all that mattered, pretty soon we’d all be living in one great big city. But the forces of agglomeration are balanced by the forces of dispersion such as traffic jams and costly housing. As the McKinsey team argues, it takes excellent management to overcome those drags. Greater Tokyo, which Japan’s statistical bureau credits with 38 million people, is well-managed, with excellent public transportation, but even it’s pushing the limits. “Cities won’t get to 80 to 100 million people,” predicts Gilles Duranton, a real estate professor at the University of Pennsylvania’s Wharton School.
Aisa Kirabo Kacyira earned a veterinary degree and went to work for the agriculture ministry in her native Rwanda, helping cattle ranchers with marketing. That ignited an interest in public policy that led to her successful 2006 run for mayor of the capital, Kigali. Almost half the residents lived in informal settlements, and the population was growing rapidly. She delegated power to grass-roots organizers to create systems for cleaning garbage. She rewarded responsive civil servants. And she promised investors they would get a response on permit applications within a month. She won an award from the UN and is now deputy executive director of UN-Habitat in Nairobi, Kenya, which works on improving urban living conditions. Says Kacyira: “People are not moving haphazardly. People sense where the opportunities are. But government doesn’t move as quickly.” That’s what has to change.