For millions of people, from accountants to the person in charge of the work rota, Microsoft Excel has been been a godsend.
But as the spreadsheet software nears its 40th birthday, spare a thought for those who misplaced a decimal, left out a row or got their cut and paste wrong. Here are some of the most memorable examples.
Austerity error
In 2010, two respected economists released a paper that made an influential case for the years of austerity that followed. Carmen Reinhart and Kenneth Rogoff argued in Growth in a Time of Debt that once a government’s debt reaches 90% of gross domestic product – a measure of a country’s economic output – growth goes into reverse.
However, in 2013 it emerged that the Harvard economists had made an error in an Excel spreadsheet: instead of falling by 0.1%, their work should have found that the economies in question grow by 2.2%.
“It is sobering that such an error slipped into one of our papers,” they said in a statement. They nonetheless stood by their broad conclusion – debt hinders growth – but the error was jumped on by critics.
“This can’t possibly be good for Team Austerity,” wrote the US economist Paul Krugman.
Utter dis-mae
Fannie Mae, the US mortgage lender, issued a quarterly results statement in 2003 containing accounting errors that totalled more than $1bn. Fannie Mae said the mistakes were due to a company accountant putting the wrong formula into an Excel spreadsheet, as the financial firm sought to comply with a new accounting standard.
The company stressed that the errors did not affect profits, but questions were raised about Fannie Mae’s internal controls at the time. Five years later, Fannie Mae was rescued by the US government as the credit crunch took hold.
Computer says 000
MI5, the UK’s domestic spy agency, tapped 134 incorrect telephone numbers in 2010 following a spreadsheet error that altered the last three digits in the numbers to “000”.
A report admitted the errors were caused by “a formatting fault on an electronic spreadsheet”, adding euphemistically that “a degree of unintended collateral intrusion occurred”.
Virus problems
During the coronavirus pandemic, nearly 16,000 cases went unreported in England after an Excel error. The Guardian reported that the mistake may have been caused by a file containing test results, sent from NHS test and trace to Public Health England, exceeding the number of rows it could contain. As a consequence, test reports were missed off and thousands of potentially infectious people were missed by contact tracers.
The then health secretary, Matt Hancock, said the incident “should never have happened”.
Whale-sized mistake
An internal report into a $6bn trading loss at the US investment bank JP Morgan, at the hands of a trader known as the London Whale, found flaws in how an important measure of financial risk at the institution was being calculated.
One problem was that the risk model monitoring the fateful portfolio operated “through a series of Excel spreadsheets, which had to be completed manually, by a process of copying and pasting data from one spreadsheet to another” – a process that might ring bells for some Excel veterans.
An error was created after a cell mistakenly divided by the sum of two interest rates, rather than the average, according to the report.
James Kwak, a US scholar, said the report outlined one of Excel’s main issues: its accessibility.
“The biggest problem is that anyone can create Excel spreadsheets – badly,” he wrote.
• This article was amended on 31 October 2024. An earlier version referred to Excel celebrating its 40th birthday, rather than nearing its 40th birthday: development of the program began in 1984, however it was not launched until 1985.
