The term "trickle-down" is more useful in teaching an economic principle than "supply-side" in its ability to encapsulate a message. So too with "middle-out". This term is more useful than demand-side in its ability to offer direction. These terms are simply more useful in describing policy or strategies than supply-side or demand-side in that they suggest a starting point. It would be useful to those discussing an economic principle, to make the term "middle-out economics" as recognizable as "trickle-down economics".