May 13th, 2021
Mapping the difference between two differences
This week, I’m happy to bring you a really, really complicated chart. I’m also happy to admit that it might be too complicated:
This map encodes, for all countries, the difference between two increases, normalized as days per week: The life expectancy increase between 1960 & 2000 and the increase between 2000 & 2016.
“Whereas wealthy countries have to content themselves with the weekly addition of another weekend to their average lifetime, Africa is gaining four days a week.”
I was intrigued by the idea to bring the numbers down to a week timeframe. Our intern Defne Altiok and I decided to check the numbers ourselves. And yes, he’s right. And yes, Africa’s increase in life expectancy is the biggest compared with other continents. But we wanted to go one step further and understand how that “weekly addition” changed over time. So we calculated the life expectancy increase not just for the last fifteen years, but also for the time range 1960-2000. What you see in the map above is the “Difference” from the last column here:
Defne also made a bar chart with the top and bottom 10 countries worldwide. It’s astonishing that only a few of them are not in Africa or the Middle East. These two regions cover both extremes in our data set:
If you want to learn more about how and where life expectancy and other important indicators changed over the past decades, join us in reading “Factfulness” by Hans Rosling. It’s the next book we will read in the Data Vis Book Club; I just announced it on Monday. See you next week for a new Weekly Chart, this time by Defne!