đź’­ Don't call time on the megacity

Cities will learn and adapt
đź’­ Don't call time on the megacity

It is easy to assume the death of the megacity as the virus rips through our nations. Density is an issue. Breathing on each other in enclosed spaces, on subway trains, in office buildings and Zumba classes. (I’ve covered much of this in previous issues of Exponential View.)

To what extent does our response to Covid-19 mark a novel departure from the trends driving the creation of the megacity?

Certainly, the commentators are in full force. My friend, Camilla Cavendish, in the Financial Times:

[M]egacities. Big urban centres are the new plague pits. New York City, America’s most crowded big city, has suffered about 23 per cent of all US deaths from the virus. [...]

In service economies, it may be cheaper for companies to operate from suburban towns. With the digital capability to work from home, people may not need to relocate to move jobs. They may prefer a house to that shoebox, with a longer commute one or two days a week.

The picture is nuanced.

Mary Bassett from Harvard University points out:

New York City Health Department data indicate that Manhattan, the borough with the highest population density, was not the hardest hit. Deaths are concentrated in the less dense, more diverse outer boroughs. Citywide, black and Latino residents are experiencing mortality rates that are twice those of white city dwellers.

That disease is devastating cities like New York because of the structure of health care, the housing market and the labor market, not because of their density.

This point is reinforced by Sameh Wahba of the World Bank who points out that

the places most affected are not simply large cities or those with high population density. They are places with poor, overcrowded housing, lacking infrastructure services, especially water and sanitation, and with minimal open spaces such as informal settlements.

It is too early to call time on the megacity.

As complexity scientist, Geoffrey West, points out in Scale:

Cities are effectively machines for stimulating and integrating the continuous positive feedback dynamics between the physical and social.

There is a correlation between increased social interaction, socioeconomic activity, and greater economies of scale.

To the same 15 percent degree, the bigger the city the more each person earns, creates and, innovates and interacts—and the more each person experiences crime, disease, entertainment, and opportunity—and all of this is at a cost that requires less infrastructure and energy for each of them. This is the genius of the city.

And thus a city is also a balance between forces of attraction and repulsion. As one of the creators of the field of complexity economics, Cesar Hidalgo, said on my podcast:

on the one hand, we have a natural tendency for economic activity to agglomerate and that tendency increases with the complexity of the economy. But on the other hand, we also have some repulsive forces. Cities become expensive, they become crowded.

The forces of attraction are the mixing, mingling, diversity, convenience, economics. The forces of repulsion the anonymity, over-crowding, expense, pollution and disease.

The balancing point between these forces is determined by many factors which change over time. If it wasn’t for the balancing point, we would have seen much larger cities than we previously did throughout history. Two millennia ago, Rome exceeded one million inhabitants, as did Alexandria. But cities did not subsequently achieve that scale again until London reached it in the 19th century.

Our first ten-million-person city, New York City, arrived in the 1930s on the back of various technology enhancements, such as electricity, mass transit, modern sanitation, steel and skyscraper production, the safety elevator. It also had developed supply chains that could efficiently provide the stuff required to build, and the provisions needed to feed.

We haven’t yet cracked the one-hundred-million-person city. The forces of repulsion— environmental footprint, transport, pollution, entrenched interests—have proven greater than the forces of attraction. But this problem is simply unsurmounted rather than insurmountable.

The coronavirus has added yet another aversive force. Do we want to sweat each other’s sweat? Breathe each other’s breath? Share pathogens? And yet… “[I]f our economy becomes more knowledge-intense, the importance of cities is going to grow, and the difference between cities and rural areas is going to grow, as well,” says Cesar Hidalgo. Is our economy becoming more knowledge-intense?

And the external demands—of bringing people out of poverty—seem to require cities. The projections remind us that most future urbanisation will take place in cities different to the European and American cities that most of my readers call home.

Source: European Environment Agency

From the 2018 UN report on urbanization: “Just three countries – India, China and Nigeria – are expected to account for 35 per cent of the growth in the world’s urban population between 2018 and 2050. India is projected to add 416 million urban dwellers, China 255 million and Nigeria 189 million.”

Source: UN, World Urbanization Prospects 2018

Even our automated systems demand proximity. The speed of light, c, remains the ultimate limiting factor. That physical constant is an immovable that the pathogen can shift. For computer systems, proximity to the action matters more than ever before. (Listen to my discussion with Adena Friedman, CEO of Nasdaq, on the needs of high-frequency trading systems.)

What might happen?

(1) Is there some sort of mid-sized scale which can, per Hidalgo, “support enough complexity to become attractive from an economic perspective?” In the US, recently the fastest-growing cities were not the biggest. Nor does San Francisco make the top ten.

(2) Can we design cities, large or small, to be more livable, more resilient to climate change and other shocks, including pandemics? Many mayors seem to think so. See this survey of how city mayors are looking to reclaim public space from cars and not clamouring to reduce their populations.

(3) People have had the option to move out of cities for years. And many have, while they commute back to a major conurbation. Between 2009 and 2017, the Bay Area has seen the growth of supercommuters (commuting for 90 minutes and more)—notice the  black dot on the map, that of San Francisco.

But moving places takes time—and to where do you move? There isn’t an infinite housing stock with infinite infrastructure to move to. And what is more, people may not want to move (not for economics, not for some hard-to-assess contagion risk). Nobel laureate Esther Duflo argues that mobility in the US is declining:

People are remarkably sticky. […] To give you an idea of how immobile people are in the US, in 1948 7% of people used to move from one county to another every year, and in the 2000s it’s closer to 4%.

Yes, the wealthy—and there are more wealthy humans than ever—can always create options to leave the hubbub of the city. And yes, remote technologies may make it more possible to work remotely, live further away. And while the pandemic is making people nervous this year, next year, and perhaps the next few years, this won’t be happening for the length of time that it takes to stop the tide of humanity agglomerating.

At the same time, cities, their designers and operators learn. They, too, get access to innovation and the know-how. They, too, look at the mess and seek to improve it. And we understand that many of the disadvantages of the city—housing, transport and income inequality—are driven by policies, not physics.

So cities will adapt and continue to bring the benefits we expect of them.


P.S. I do recommend you listen to my discussion with Sameh Wahba. It is available here.

Photo by Devin Avery on Unsplash


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