Counting is hard (redux)

Diving into coronavirus numbers (or lack thereof)

Photo by Leonel Fernandez on Unsplash

As a resident of the UK I joined many people in tuning in to watch Boris Johnson talk about my country’s response covid-19 and the path out of lockdown. In my previous post on why counting is hard I talked about how we report numbers. Then I saw the way we’re presenting numbers and despaired a little. This post is about why the things we’re reporting don’t give an accurate picture of how we’re doing or incentivise the right things. The UK’s response can be used as a case study in a project update that doesn’t meet the needs of its audience.

First of all I want to re-acquaint you with Goodhart’s Law which says:
“Any observed statistical regularity will tend to collapse once pressure is placed upon it for control purposes.”
This is regularly paraphrased to:
“When a measure becomes a target, it ceases to be a good measure.

So, let’s take a look at the measures which the UK government are reporting on and dig into why they may not be meaningful. Then talk about some questions we can which might give greater clarity and lead to better metrics.

Number of new infections. Limited by your ability to test infected people at the right time. This gives you an indicator of how rapidly the virus is spreading so is…