March 20, 2020 - 12:24pm

No, Matt Hancock, Covid-19 is not a once in a century event. That’s how he described the pandemic on Question Time last night.

One can understand why he said it. The Health Secretary was underlining the gravity of the situation. And, indeed, no pandemic has hit us so hard since the Spanish Flu, about a hundred years ago.

Hancock is hardly alone in taking this perspective. Back in February, Bill Gates said that coronavirus could be the “once-in-a-century pathogen we’ve been worried about.”

Gates’ worries were clearly justified. But there’s a huge problem with the description of once-in-a-century. It’s not that it exaggerates the current crisis, but that it suggests there’s a ceiling on the risks we face from future pandemics.

For a start, we can’t rely on the next such event occurring a hundred years in the future — not even if that does prove to be the average interval over time. A yet bigger mistake, however, would be to conclude that a Spanish Flu or a Covid-19 represents an upper bound of destructiveness.

It doesn’t. As a phenomenon, infectious disease exemplifies the concept of multiplicative risk. It does not exist in what Nassim Taleb calls ‘Mediocristan’ — the realm of limited probabilities. Rather it belongs in ‘Extremistan’ — the realm in which the most extreme outcomes, though very unlikely to occur at any particular time, are very extreme indeed.

These are Taleb’s infamous black swans and by their very nature they are unpredictable. All we can do is limit our exposure to them.

In respect to pandemic risks, however, we’ve been doing the very opposite — constructing an ultra-globalised economy held together by fragile supply chains and perched precariously on a mountain of debt.

Peter Franklin is Associate Editor of UnHerd. He was previously a policy advisor and speechwriter on environmental and social issues.