I just learned something interesting. Who came up with the 80/20 rule? Vilfredo Federico Damaso Pareto. According to Wikipedia, he was born in 1848, an Italian engineer, sociologist, economist, political scientist and philosopher.
The 80/20 rule was named after him as the Pareto principle. It is applicable to a great many things like 80 percent of sales are generated by 20 percent of a company's customers.
The 80/20 rule is not the interesting thing. I learned that a long time ago. The thing that is interesting, and new to me, is that Pareto extended the 80/20 rules and developed the Pareto Distribution.
When talking about production, roughly speaking, the square root of a population will have 50 percent of the stuff. The square root of the population of a company's factory work force will have 50 percent of the benefits.
When talking about economies, the square root of the population will have 50 percent of the money. This happens regardless of the economic structure. It doesn't matter if the structure is Capitalism, Socialism or Communism.
This means that equality of outcome, the dreams of socialists and communists, is impossible.
So when you meet someone decrying the 1 percent, tell them it's just the way the world works and point to the Pareto Distribution.