Why is a false negative Covid-19 test far more dangerous than a false positive?
If a person is mistakenly declared to not have the disease, it would give them a false sense of security. They would then end up spreading the disease to a 100 more people and amplify the crisis. A false positive, one that points to somebody having the disease even if they don’t, would put them through two-weeks of isolation – an inconvenience for the individual concerned, but benign for society as a whole. With Covid-19 tests, you need to be more careful about false-negatives than false positives.
A good non-fiction book costs about €10 to buy. Within certain boundaries, the worst thing that could happen with such a book is that you end up reading it for 6 hours and you don’t learn a single useful thing. On the flipside, such a book could teach you something that ends up transforming your life for the better. With book purchases, you can afford to care less about the monetary expense.
Care is a scarce, non-renewable resource. You cannot absolutely care about every single thing. If you did, you would live inside a bio-bubble, have military grade cyber security and soon be bankrupt. The solution is to use care judiciously for cases where the downside risk is higher.
Observations 