I forget what little I ever knew about statistics but we’re probably talking about the normal distribution of human characteristics of any sort. There will always be those that stand out from others and the real stand outs will be a minority, 20% or less. I look back at growing up and the athletes that were in my classes. There was always a superstar or two in every class but from those at the top it trailed off to those who could only “throw like a girl.”
I read this article that applies the principle to more that just economics:
Now if only the media would pick up and expose the idea.
It's like a gyroscope. You can push it one way or the other, but it will tend toward the 80/20 split.
Like I said, it relates to energy conservation in biological systems. There's a branch of economics called "econophysics" that developed from this insight.
But, it's not news by any stretch of the imagination. Guys like Krugman surely know that any system will move to the 80/20 split.