The tyranny of spreadsheets

Tim Harford at the Financial Times: “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….

The origin of Excel can be traced back far further than that of Microsoft. In the late 1300s, the need for a solid system for accounts was evident in the outbursts of one man in particular, an Italian textile merchant named Francesco di Marco Datini. Poor Datini was surrounded by fools.

“You cannot see a crow in a bowlful of milk!” he berated one associate.

“You could lose your way from your nose to your mouth!” he chided another.

Iris Origo’s vivid book The Merchant of Prato describes Datini’s everyday life and explains his problem: keeping track of everything in a complicated world. By the end of the 14th century, merchants such as Datini had progressed from mere travelling salesmen able to keep track of profits by patting their purses. They were now in charge of sophisticated operations.

Datini, for example, ordered wool from the island of Mallorca two years before the sheep had even grown it, a hedge to account for the numerous subcontractors that would process it before it became beautiful rolls of dyed cloth. The supply chain between shepherd and consumer stretched across Barcelona, Pisa, Venice, Valencia, North Africa and back to Mallorca. It took four years between the initial order of wool and the final sale of cloth.

No wonder Datini insisted on absolute clarity about where his product was at any moment, not to mention his money. How did he manage? Spreadsheets…(More)”