The strange idea of negative interest

This article by Graham Barnes addresses the role of demurrage (negative interest) in the design of new currencies. But it takes a roundabout route with diversions around the zero and negative interest rates being currently applied to fiat money; and a detour via positive interest which is itself a stranger idea than we have been led to believe. It suggests that demurrage is worth a place in the designer's kitbag, but not for the reason normally postulated.