The Martin Prosperity Institute here in Toronto recently published an interesting report called The Geography of the Global Super-Rich.

What they did was use the Forbes 2015 Billionaire List to chart billionaires and billionaire wealth by location and by industry. They also looked at the wealth gap in each location and whether the wealth was self-made or inherited.

A correlation analysis was also done to see what key variables – such as population, density, economic output, global city standing, VC investment, and so on – were positively correlated with a greater concentration of super rich people.

There are 1,826 billionaires across the world according to Forbes. The researchers were able to match 99% of them to a specific metro area / primary residence.

Here are the top 20 metro areas in terms of the number of billionaires:

Look at Miami at #9. 

I suspect that this may surprise some of you. But Miami has grown into a significant global city. As one of my friends from Miami likes to tell me: “The best thing about Miami is that it’s a Latin American city that’s so close to the United States.”

Here are the top 20 metro areas in terms of total billionaire wealth: 

A bunch of changes on this list because of extremely wealthly people and families in places like Bentonville (Arkansas) and Omaha.

One of the conclusions of the report is that the size of the city generally matters:

“The geography of the super-rich is a function of larger cities. Both the number of billionaires and their net worth are positively associated with the population of global cities, with correlations of 0.56 for the number of billionaires and 0.44 to their net worth.”

Here is a chart comparing population to the number of billionaires:

Cities such as New York, Moscow, and Hong kong, which sit far above the blue line, have more billionaires than their population size would predict.

Here is a similar chart comparing venture capital investment to the number of billionaires:

Once again, there is a positive association.

Finally, here are a two charts that show which industries have produced the most billionaires:

If you’re interested in this study, you can download the full report here. All of the charts were sourced from the report.

One of the most interesting things about cities is that as they grow their “urban metabolism” also tends to increase. People become more productive. Economic output increases. It becomes easier to hail a cab (which is a test I like to use). And, according to this recent article by CityLab, people walk faster.

Yes, research has shown that there’s a correlation between population size and the speed in which people walk. And some of the studies go as far back as the 1970s – like this one from psychologists Marc and Helen Bernstein:

In many ways, this makes intuitive sense. Life in the big city is a fast paced one. But why exactly do people start literally walking faster? The most probable answer seems to be, quite simply, that time is money. Subsequent research from the 1980s and 1990s has revealed that the best predictor of fast walking is economic output.

When a city grows larger, they wrote, wage rate and cost of living increase, and with that the value of a resident’s time. As a result, “economizing on time becomes more urgent and life becomes more hurried and harried,” Walmsley and Lewis suggest. (Source: CityLab)

The first thing that crossed my mind when reading all of this is that there must be some sort of upper limit. Humans don’t just keep walking faster and faster as the city in which they live in grows bigger. If that were the case, the mega cities of the world – such as Tokyo – would have people sprinting around all the time. But that’s obviously not the case.

So this is a topic that could probably use some more data. And I would imagine it would be a lot easier to collect today given that we all now walk around with mobile sensors in our pockets (our smartphones). And pretty soon we may have mobile sensors on our wrists (smart watches).

I would certainly like to see more data on this. The idea of an “urban metabolism” has always interested me.

Image: Dundas Square, Toronto via Flickr