The Tyranny of Spreadsheets

Tim Harford:

Early last October my phone rang. On the line was a researcher calling from Today, the BBC’s agenda-setting morning radio programme. She told me that something strange had happened, and she hoped I might be able to explain it. Nearly 16,000 positive Covid cases had disappeared completely from the UK’s contact tracing system. These were 16,000 people who should have been warned they were infected and a danger to others, 16,000 cases contact tracers should have been running down to figure out where the infected went, who they met and who else might be at risk. None of which was happening. 

Why had the cases disappeared? Apparently, Microsoft Excel had run out of numbers. 

It was an astonishing story that would, in time, lead me to delve into the history of accountancy, epidemiology and vaccination, discuss file formatting with Microsoft’s founder, Bill Gates, and even trace the aftershocks of the collapse of Enron. But above all, it was a story that would teach me about the way we take numbers for granted. 

Now, as the UK tentatively reopens against a background of rapidly rising cases, we are hoping that vaccinations will keep us safe. The vaccines have — rightly — been trumpeted as a scientific triumph. Their development and rollout have taken place on a heroic scale. 

But back in September and October, when the UK was also reopening against a strikingly similar backdrop of rising cases, we had no vaccine to protect us. Instead, we were trying to defend ourselves with data. And we didn’t seem to be nearly as enamoured of data as we now are of vaccines. That is a shame, because when you’re relying on numbers to keep you safe, it’s important to put some effort into keeping your numbers straight.