“On why The Economist always lists solutions in sets of three, a wise colleague once said:
One point? Don’t be political. It is never about just one thing.
Two points? You’ve not thought enough about the problem. Do more research.
Four points or more? Summarise and cut the waffle.
Yup, three points in a list is just about right.”
Via The Economist https://www.economist.com/letters/2020/06/04/letters-to-the-editor