Sunday, August 16, 2020
I fear for graphs.
We've grown used to using them to draw conclusions from economic and social data. Now suddenly the latest bar has shot right off the chart obscuring all the patterns that were previously apparent.
This is a graph of UK GDP produced by the BBC website this week.
It shows a whopping decline of 20% in the last quarter, ten times greater than any other bar on the chart. This is indeed the story of the moment, an unprecedented economic shock from which many businesses may never recover. But the ruptured scale means the patterns of the last decade have been almost completely obscured, and even the financial crisis of 2008 registers as a blip when it was anything but.
This graph is how the BBC depicted UK GDP in February before the pandemic hit.
It shows a lot more detail, still with plenty of volatility but within normal bounds. In the February 2020 graph you can see patterns over a decade. In the August 2020 graph all you see is now.
As we go forward into whatever the next decade brings. 2020 will always be there warping the graph.
And not just for GDP but for unemployment, retail footfall, environmental emissions, exam results, passenger transport... an entire suite of statistics now has a giant blip in it. Eventually we'll be able to chop it off (just as the BBC chopped 2008 off the start of the second graph). But until then, and for the foreseeable future, I fear for graphs.
<< click for Newer posts
click for Older Posts >>
click to return to the main page
