Without a question, we are living in an urban era. More people now live in cities than anywhere else on the planet and I've repeatedly argued that cities are our most important economic engine. As a result of these demographic and economic shifts, we're seeing megacities at a scale the world has never seen before. Below is a list of the top 35 largest urban areas in the world.

The top urban area is Tokyo-Yokohama, with a population of roughly 37.5 million people. That's almost the same as the state of California and is more than the entire population of Canada, which sits at just over 35 million people. London, which, during the 2nd half of the 19th century, would have been the largest urban area in the world is now the 29th largest.

But at the same time, London arguably remains the most important global city—a title that can only really be rivalled by New York. Which raises an important distinction. One that Aaron Renn clearly identifies in this recent article for New Geography: Just because a city is a megacity, doesn't mean it is or will ever be a global city. In fact, Renn argues that many of the world's largest megacities will never "turn the corner" and become leaders of the global economy.

For that to happen, he believes that the city needs to belong to a country on the rise:

Moscow was the capital of the Soviet Empire. New York and Los Angeles came of age when America was the rising, and ultimately dominant, economic colossus. It's the same for Paris and London, two borderline megacities, which rose as imperial capitals. 

But how much of this is driven by the country and how much of it can be driven by the city itself, upwards? Could it be the city that ultimately empowers the country to rise? I ask these questions because Renn frames his argument as if "national hyper growth" is the only prerequisite that will allow the struggling and underdeveloped megacities to pull themselves up and into the developed world.

But the problem is that there's no clear path to prosperous maturity for these megacities.  They are so huge, and their problems so immense that they are difficult to even conceptualize, much less do something about.  The amount of needed infrastructure provision alone – water, sanitation, drainage, transport, telecom, electricity, parks, schools, etc. – is staggering. And that doesn't even touch arguably more difficult problems like corruption and good governance. Absent national hyper growth – a la Japan or Korea – of a level that creates a plausible claim to being the world's rising economic power, or the proceeds of empire, it seems unlikely any of these cities will ever succeed. By contrast, smaller cities have a much more addressable problem space.

Now, I don't disagree that the problems in these cities seem almost insurmountable. I've been to places like Dhaka, Bangladesh. I've witnessed first hand the challenges facing megacities in the developing world. 

But to assume that these cities are lost causes without the nation itself lifting it up, seems almost self defeating and overly pessimistic. It also strikes me as a bit of a chicken and egg scenario. Because if cities are our economic engine, then "national hyper growth" seems difficult without also getting our cities right.

What comes first?

Yes, there are and will be reforms that need to happen at the federal level but, at the same time, I think there's a lot that can and should happen from the ground up. Perhaps that's part of the reason Singapore has been so successful. As a city-state, its reforms were both top down and bottom up. 

I want to believe that with the right reforms, policies, and leadership, any country can create a framework in which its cities are able to thrive. And that it's not just the result of imperial rule or some other circumstance. From good and transparent governance to developed financial markets, there are many things that cities need to truly prosper. But when you get it right, the results can be remarkable. 

Chart: Demographia

Photo Credit: Megacities and Development/shutterstock