Tuesday, October 20, 2015

Metropolitan areas: the new cities

Some time ago, I decided to do some calculation on the proportion of people in certain countries that live in large metropolitan areas. To be frank, I did it mainly to check out the claim that North America cannot have urban areas like Europe because there is too much land and too few people, so of course population is more spread out. Using citypopulation.de (a great resource for urban populations and density) and public data on total population, I came up with the following results for the proportion of a country's population living in metropolitan areas with more than one million inhabitants:
In red, Asian countries, in light blue, European countries, in orange, European offshoots
Not surprisingly, island nations with a lot of mountains or deserts tend to have higher population concentration inside a few metros than other nations. However, a clear trend is how the population in European offshoots (former colonies) is much more concentrated in big metro areas than the population in Europe. Europe is a continent of mid-sized cities, North America is a continent of huge metros with almost uninhabited areas between them. So, all in all, North America ostensibly has more potential for big metropolises than Europe.

But what is a metropolitan area?

One objection to these numbers was that the definition of metropolitan area varies from country to country. Metropolitan areas in the US and Canada are extraordinarily large, whereas they are far more compact in Europe. For example, Greater Paris represents an area of 824 square kilometers, the Atlanta Metro area totals 21 694 square kilometer, 26 times bigger, though Paris has about 25% more people.

However, I believe that this difference is not due to a fundamental difference in what defines a metropolitan area, but due to the different urban organization and transport infrastructure.

But what defines a metropolitan area? I think that to properly understand what is a metropolitan area, one must first understand what is a city, because they are in many ways functionally similar.

What force binds a city together and defines it? Community? In cities, there are many different communities, each forming separate neighborhoods, so though community is a bound present in cities, it doesn't define them. Culture? As I live in Montréal, where Western Montréal is anglophone and Eastern Montréal is francophone, and the difference is flagrant, that seems self-evidently wrong too. Shared identity? Though present in many cities, identity is more likely a consequence of the city's existence, and not its originator.

Ultimately, I believe a city is bound together mainly by economics, that, in fact, economics are the very reason that cities exist in the first place. A city is mainly defined by economic activities, workplaces, businesses, services that draw in people looking to benefit from the opportunities that exist in cities and from the diverse and rich products and services that result from all this economic activity. So everyone living in a city wants to be in a location to be able to access these activities. This largely means that a city is defined by commuting distance. As a whole, cities represent an area where economic activities occur within commuting distances from each other, forming a local economy.

So if a city is defined by economics, so should a metropolitan area, but what is the difference? In fact, the difference is next to non-existent. Like cities, metropolitan areas are also bound by commuting distance and by the proximity and concentration of economic activities that form a local economy. However, cities are also political entities, and these entities were usually formed in a previous era, before cars, before buses, before streetcars and before trains (except for some recent cities). A city born in a pre-motorization era could only encompass an area defined by a walking commute, which is limited by a walking speed of roughly 5 km/h.
Paris intramuros (between the walls) forms roughly a circle with a 5-km radius around its center, equivalent to a 1-hour walking distance.
Many cities are still politically bound to these borders from another era, as in the case of Paris, though some others have known mergers which have brought larger areas under control of one authority.

With the invention of new, faster means of transport, commuting distance has been extended, bringing more economic activities under the same local economy and allowing cities to expand. However, the political boundaries have not followed in most cases, leading to economically integrated areas with fragmented political leadership, sometimes with a disjointed urbanized area with gaps between urban centers.

So, in a way, metropolitan areas ARE the cities, but often split in several entities connected to each other through high-speed transport links.

But how can this explain why Greater Paris is just 824 square kilometers and Atlanta's metropolitan area is 21 694 square kilometers, supposing both metros are defined the same way?

The reason, I believe, is that the European development pattern is different from the North American one. European countries have largely avoided building freeways through cities and have struggled to keep economic activity centers (offices, shops, services) at the center of cities. Meanwhile, North America has often done significant "urban renewal", pushing highways through cities and allowing, even encouraging, economic activities to migrate to highway interchanges, which is the pattern Atlanta has adopted.

As a result, to reach activity centers in European cities, people often have to go through urban areas, which slows down significantly intercity car trips, increasing commute times and thus limiting how far the region can integrate economically.

The European pattern of highways going around cities with vibrant activity centers inside cities, which limits economic integration of the major city as crossing urban areas to each commercial centers consume a lot of time
With activity centers placed at interchanges, it allows for them to connect much faster through the high-speed network, increasing commuting speed and integrating a large region
Over time, as metro population grows, attracting more people and activities by the amount of opportunities offered, the population will distribute itself into that area, defined by commuting speeds. As the area is more limited in the European pattern, the population will concentrate in a smaller area, and cities left outside those borders will either stagnate or join mid-sized regional cities, creating a pattern of relatively compact mid-sized cities separated by wide undeveloped areas:
Natural evolution of the European pattern
Meanwhile, the North American pattern will encourage sprawl. People who want to join a metro area are able to live in a very wide area. This favors a wide dispersion of population, but still within the borders of the metropolitan area, which still draws in people looking for better economic opportunities.
Natural evolution of the American pattern
It is important to remember that both the person going to live in a dense, compact urban area near a major European city and the person relocating to a farther suburb, or exurb, of a major American metropolitan area are seeking the same thing: proximity to a strong and diverse local economy to benefit from the opportunities, products and services that it produces.

Is the future more or less urbanization?

I think this is a good point to start on a tangent on the phenomenon of urbanization. Every country that has seen a significant improvement in living conditions has seen a massive movement to cities. That is because economic activities gain efficiency by concentrating, and the concentration of resources provide more opportunities than their dispersion. Still, there are economic activities that cannot be relocated like agriculture, mining and natural resource exploitation. However, these activities, thanks to gains in productivity, require less and less people to actually do them.

Mines that in the 19th century could sustain an entire town by employing most of the male population can now employ only a fraction of that population while producing as much ore, or more, than before. Farm sizes exploded thanks to new machinery that allowed one person to plant and harvest vastly more land than before, reducing the need for a high number of farmers. Most economic activities however can be relocated, and they gain from gathering in a few places where their presence can lead to the emergence of support industries and where they can benefit from local expertise. That created a bias for cities that has never reversed.

Never reversed, really? Yes, really. As I said, metropolitan areas have become the new cities, and if I look at the population of the top 20 most populous metros in the US versus the US census population, here is what I get:
Population (in thousands), US total versus top 20 metros
OK, this graph doesn't clearly demonstrate a trend of metropolitan growth versus national growth, so here is a graph showing population relative to 1910 (which is 100) to see cumulative proportional change in both national population and top 20 metro population:
Population (1910=100), US total versus top 20 metros
Here, the top 20 metro curve is much higher than the US total population curve. This shows that the top 20 metros have gained population at twice the rate of the country as a whole. If we want to look at the proportion of the US population residing in the top 20 metros, here is what we get:
This shows the share of population in the largest metro areas keeps increasing, for a hundred years, the increase has only slightly slowed down over time, but the trend is still clearly positive.

So I guess QEDs are in order here. BTW, source for the top 20 metro population.

Unfortunately for those who long for the traditional lifestyle, that traditional lifestyle is simply unable to provide the resources and wealth required to maintain a modern quality of life. Just like nations, one can do calculations of accounts of trade for cities, calculating their "current accounts balances". Cities that fail to export enough to pay for their imports of goods and services from outside their borders face constant community impoverishment that leads to their decline.

So ultimately, cities that have not reached critical mass to have an economy that can have a current account surplus are, well, doomed as their people get progressively poorer until they have to move out. This includes many isolated villages, many of which in North America are Native Reserves. It is my conviction that much of the troubles that afflict reserves are due to their inability to create a local economy that can balance the books of the money entering and leaving the reserves. Official policy tries to help them maintain a traditional lifestyle, but that traditional lifestyle is unable to sustain modern quality of life, leading to massive subsidy requirements that often fail to fully compensate the gap. Reserves that exist inside metropolitan areas like Kahnawake and Wendake in Québec have much higher quality of life and far less of the social problems that afflict isolated reserves, which are artificially maintained in conditions that would often lead to the closing of villages in the same conditions.

Some say that technology allowing telecommuting may allow for a "return to the land", I'm more than doubtful. Even if we discount the loss of knowledge transfer resulting from face-to-face communications, there are plenty of goods and services that can't be remotely accessed, and so metropolitan living will remain desirable.


I know some may start thinking I'm rambling, but I think it's important to underline that the very basis for cities' existence is economics, it is local economies that bind cities together more than community, culture or identity. In the modern world, economical pressures keep pushing economic activities and people together, though transport has expanded the definition of "proximity", allowing cities to morph into metropolitan areas, which have become the real modern cities.

The concentration of North American populations in metropolitan centers put the lie to the idea that cities are ill-adapted to the North American context. People who come live into a city's suburbs in its metropolitan area go there because they want to join the local metropolitan economy and benefit from its opportunities and wealth. Transport infrastructure will influence how the metros develop and how far they extend, but ultimately, the move to metros is an economic fact of modern life.