How do face masks REALLY impact COVID-19

Would you be willing to commit to wear face masks whenever you are outside of your home, to be allowed to return to work?

Last week I read a post from Nassim Taleb where he shared a graph that showed a clear correlation between countries whose citizens wore face masks whenever they were outside of their homes, and those countries whose citizens did not or started later.

The graph quoted was around a month old, and showed cumulative COVID-19 cases. I was curious what had happened since then to the correlation.

So, this weekend, using data from, I created my own chart but this time showing COVID-19 related deaths by country.

Yes, correlation does not imply causation, especially in a complex case like COVID-19, but it is a very interesting correlation…

…which is what made me think of the question at the beginning of this post.

Here it is again:

Would you be willing to wear a face mask whenever you are outside of your home (and use hand sanitizer whenever you touched surfaces), to be allowed to return to work?

PS: Hong Kong is also on the list of countries where wearing masks was more the norm rather than the exception from early on. It just doesn’t show on the graph as the COVID-19 related deaths are so low (only 4 deaths so far with population of 7.5m.

Check out my COVID-19 series to read about our research into COVID-19 Recovery and Duration.