21; or a different number

In COVID times, we are constantly bombarded with figures, statistics, and bold claims. How many people will die? On average, how long do patients stay in ICU? How many ICU bed will be needed? How long will it take to flatten the curve?

Some of these figures will turn out to be true. Others less so. And many will be structurally biased.

This is best illustrated by an innocent example: The most successful weatherman is not the one who makes the most accurate prediction of rain or shine, but the one who predicts rain a bit too often. No-one will blame him when it turns out to be a sunny day. A faulty prediction of sunshine will be less appreciated by his audience.

Similarly, it is best to over-estimate the number of ICU beds you need two weeks from now. That is just proper risk management.

Just be aware: correctly interpreting the figures you see in the news may require game theory as much as it requires statistics.