Monetary Velocity
This is a great video to introduce the concept of monetary velocity. Monetary velocity is a measure of economy decribed in economy books in detail. It tells us how quickly money changes hands within an economy. The monetary velocity will affect the money supply. Therefore it is of interest to monetary policy.
Let us look at the story. Beavis and Butt-head were supposed to be selling candy bars as part of a school fundraiser. They each had a box of candy bars, with the cost of one dollar each to sell for two dollars. They first settle the lack of purchasing power with one dollar credit to friend. Then Butt-head and Beavis buy a candy from each other in turn. They keep passing the dollar bills back and forth and before long they have both “sold” all of their candy bars.