Q11 – Megacities

This question was asked to the public in Sweden, Norway, Finland, Denmark and the UK in the Sustainable Development Misconception Study 2020

In December 2020 Gapminder launches a brand new service for upgrading your worldview, where you will be able to take this (and many other) tests and become certified gapm.io/upgrader


What share of the world’s population lives in megacities (cities with at least 10 million people)?

a) Around 8%

b) Around 28%

c) Around 48%

Correct answer

Less than 8% of the world’s population live in megacities.

Megacities get all the attention

It doesn’t matter what country you live in, the media probably pays much more attention to the people living in the capital and other large cities, compared to the rest of the population. Intuitively the reason is that more people live in a few big cities, but if you do the math, in many countries, there are actually more people living in middle-sized cities, and those are often growing just as fast as the few big cities.

More than half the world’s population live in cities and that share keeps increasing. But there are only 33 cities with more than 10 million inhabitants in the world today. Almost all city dwellers live in much smaller cities.

There are many benefits and challenges with urbanization, and there’s a lot to learn from other cities. But the benefit of learning from megacities is limited, as only 14% of all urban dwellers live there, which is only 8% of humanity. But looking at the result from this question we can see how the exaggerated attention on megacities has made lots of people believe that roughly a third of humanity live in them.

Data source

According to the UN[1] in 2018, 529 million people lived in 33 cities with more than 10 million inhabitants. That is 6.9% of the world’s population of 7.6 billion. But in this question we use 8% as the correct answer to make sure we are not understating the number, as so many believe it is much higher. The UN estimate could potentially be a bit too low, as there is no international standard for defining city boundaries when counting citizens. The UN report mixes methods used by different countries. If the more generous methods that include sparsely populated outskirts were used everywhere, then a few more cities would maybe qualify as megacities.

Despite that legitimate concern, most cities are not even close to 10 million people, so even adding a couple of more million extra people to most cities wouldn’t make a big difference to the number of megacities.

However, we chose to put the correct answer as 8% to try to take into account any data concerns about underestimation of city size and the fact that the data is from 2018. Even if the number of megacities and their population sizes are increasing, it will probably not reach 8% for many years. The UN[1] projects that the number of megacities will grow from 33 to 43 by 2030, but the people living in them will still only make up 8.8% of the global population. Of all urban dwellers then, an even larger share will live in cities that are not megacities.

Source 1 – UN – The World’s Cities in 2018