Daily insights for city builders. Published since 2013 by Toronto-based real estate developer Brandon Donnelly.

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Boy, population densities can be so misleading. The typical approach is to just take the number of people and divide it by a given area. This then gives you something like X number of "people per square kilometer." The problem with this approach is that there are countless factors that can skew your result.
Hong Kong, for instance, is really dense. But as a city, it also has a lot of green space, mountains, and other undeveloped areas. Only about a quarter of Hong Kong's land is developed. So when you divide total people by its administrative boundary area, it is going to appear less dense than it really is.
One alternative approach is to use a method known as population-weighted density. The way this works is that you take the average densities of smaller more granular subareas and then weight them by the population of each subarea. It is a little more complicated to calculate, but the overall intent is to try and capture a density figure that more accurately reflects what the average person experiences on the ground.
And this is exactly the method that Jonathan Nolan decided to use in his new website CityDensity.com. What his site allows you to do is compare population-weighted densities across various cities, and then see how it tapers off as you move outward from their city centers.
Once again, it is hard to beat Paris' supremely dense mid-rise built form:

Boy, population densities can be so misleading. The typical approach is to just take the number of people and divide it by a given area. This then gives you something like X number of "people per square kilometer." The problem with this approach is that there are countless factors that can skew your result.
Hong Kong, for instance, is really dense. But as a city, it also has a lot of green space, mountains, and other undeveloped areas. Only about a quarter of Hong Kong's land is developed. So when you divide total people by its administrative boundary area, it is going to appear less dense than it really is.
One alternative approach is to use a method known as population-weighted density. The way this works is that you take the average densities of smaller more granular subareas and then weight them by the population of each subarea. It is a little more complicated to calculate, but the overall intent is to try and capture a density figure that more accurately reflects what the average person experiences on the ground.
And this is exactly the method that Jonathan Nolan decided to use in his new website CityDensity.com. What his site allows you to do is compare population-weighted densities across various cities, and then see how it tapers off as you move outward from their city centers.
Once again, it is hard to beat Paris' supremely dense mid-rise built form:


Canada must become a global superpower
The silver lining to the US starting a trade war with Canada and regularly threatening annexation is that it has forced this country out of complacency. Indeed, I'm hard pressed to remember a time, at least in my lifetime, when patriotism and nationalism has united so much of Canada. According to a recent survey by Angus Reid, the percentage of Canadians expressing a "deep emotional attachment" to the country jumped from 49% in December 2024 to 59% in February 2025. And as further evidence of...

The bank robbery capital of the world
Between 1985 and 1995, Los Angeles' retail bank branches were robbed some 17,106 times. In 1992, which was the the city's worst year for robberies, the number was 2,641. This roughly translated into about one bank robbery every 45 minutes of each banking day. All of this, according to this CrimeReads piece by Peter Houlahan, gave Los Angeles the dubious title of "The Bank Robbery Capital of the World" during this time period. So what caused this? Well according to Peter it was facil...

Canada must become a global superpower
The silver lining to the US starting a trade war with Canada and regularly threatening annexation is that it has forced this country out of complacency. Indeed, I'm hard pressed to remember a time, at least in my lifetime, when patriotism and nationalism has united so much of Canada. According to a recent survey by Angus Reid, the percentage of Canadians expressing a "deep emotional attachment" to the country jumped from 49% in December 2024 to 59% in February 2025. And as further evidence of...

The bank robbery capital of the world
Between 1985 and 1995, Los Angeles' retail bank branches were robbed some 17,106 times. In 1992, which was the the city's worst year for robberies, the number was 2,641. This roughly translated into about one bank robbery every 45 minutes of each banking day. All of this, according to this CrimeReads piece by Peter Houlahan, gave Los Angeles the dubious title of "The Bank Robbery Capital of the World" during this time period. So what caused this? Well according to Peter it was facil...
Well, that is, until you check out Hong Kong:

Charts: CityDensity.com
Well, that is, until you check out Hong Kong:

Charts: CityDensity.com
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