#FlattenTheCurve

Hi, this is Lisa; I’m responsible for the blog and the general communication at Datawrapper. I published lots of live-updating charts, maps, and tables about the coronavirus last Friday. Guess what today’s chart is about.

Edit: We don’t know how many people are infected because the amount of testing differs widly in different countries. We do know how many people died due to the virus. That’s why I changed the chart to show the number of deaths instead of confirmed cases. You can still find the chart showing confirmed cases here.

By now, #FlattenTheCurve is trending on Twitter. We collectively learn that “it is not the number of cases and deaths that matters. It is their growth rate that matters”, as Max Roser from “Our World in Data” explains in this tweet. The trajectory is important. And many countries are on the same:

Some media outlets have published a chart on a log scale like the one above, like SPIEGEL or the Financial Times (that’s an excellent one, with great annotations). What I haven’t seen so far is this chart with the number of confirmed cases in Europe, and with helper lines that explain doubling times.

Doubling times?

The doubling time is the time a population (e.g. coronavirus cases) needs to double. Let’s compare Norway and Japan to understand its consequences.

If Japan follows the course it’s on, it will double the current number of confirmed COVID19-infected people in a week. Instead of the current 650 cases, there’d be 1,300. And 2,600 in two weeks.

Norway is on a course to double its confirmed cases every second day. (Norways is in the chart, but hidden – hover over the lines to find it!) There are currently 600 confirmed cases. In a week, Norway might have to deal with 6,800 cases. A week later? 76,800 cases.

Or not. Norway – and all the other countries that currently show a steep growth rate in their coronavirus cases – might flatten their curve, like South Korea, China, Japan, and Hong Kong successfully did.

You can compare the impact of different doubling times in the following table. They’re the same I show in the chart above. China, South Korea, Japan and Hong Kong’s coronavirus cases doubling time is currently either a week or less, so they’d be in the blue columns. Europe and the US have currently doubling times that are colored in pink here:

The main priority of many nations right now is to move to a slower doubling time. That’s what #FlattenTheCurve is about. Locked down areas, school closings, conference and sports event cancellations, washing hands, avoiding gatherings – all of this ensures slow doubling times, therefore less crowded hospitals and therefore a lower case fatality rate.

I’ll end with a great GIF that sums this all up. A GIF which you’ve seen probably on Twitter already – but if you haven’t, I don’t want you to miss it:

GIF showing what Flatten The Curve meansIllustration by Toby Morris for the New Zealand online magazine The Spinoff


Phew, that was not the first article about the coronavirus you read today, was it. Maybe turn off your smartphone for a while. Take a deep breath. Stretch a bit. Try yoga. Or read a novel. We’ll see you next week.

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