Hello and welcome to more or less on the BBC World Service with a programme that fires

the harpoon of truth into the sea of suspect statistics and I'm Tim Harford.

This year the news has been dominated by one story.

You might have heard us mentioning it once or twice.

Covid Covid Covid Covid Covid

It's an important advice on racing jellyfish.

Coronavirus Covid 19 coronavirus coronavirus Covid cases.

Yes the SARS-CoV-2 pandemic.

Many countries have now had cases of the virus for eight months or more.

It seems like a long time, but in terms of studying and understanding the disease,

we're still very much in the early stages.

And this can lead to confusing headlines and potentially misleading statistics,

such as this, from the British tabloid newspaper The Sun.

Have you had it?

Stagger in 86% to tested Covid positive in lockdown had none of the official symptoms, Docs Warn.

The Sun is citing a paper by scientists at University College London,

which argued that more widespread testing was needed to catch silent transmission

from people who are asymptomatic.

Using data from a large population study conducted by the UK's Office for National Statistics,

the authors found that 86% of people who tested positive for Covid-19 had no symptoms.

So job done, right?

Well, it's a bit more complicated than that.

...