I think it's more like... better/higher/specific education means more money...
Today in class not learning about linear agebra or anything math related that I have forgetten becuase I had it years ago....
The teacher was listing all the stuff he was certified to do... and he had 4 of them... and as he moved down the list... he was listing the pay you could expect to see...
and it went up, and up and up!
also, as he went through the list... he was saying that each test he took to be certified for them was hard and got harder and harder...