KATUBA is an oceanic world both ruled and wholy owned by a queen who traces her matrilineal bloodline back to the first human to live there.  Almost all economies are to some degree based on an agreed fiction, but the Katuban economy is more imaginary than most.  The queen literally owns everything on the planet, including the people.  So any object to be used or meal to be eaten is officially lent or gifted by the queen herself.  Obviously she can't be expected to personally announce these grants all the time, so one must simply take what one considers to be fair and hope that the queen agrees.  Within her experienced mind there is presumed to exist a sort of ledger which tracks each person's merit as balanced against the resources consumed by that person.  There is minimal scarcity on Katuba, with abundant food everywhere and no need for shelter or clothing in its warm calm waters.  Only technological facilities are very limited, and these are predominantly used in the creation of esoteric vehicles.  When someone gets an idea for a new one, they wait their turn at the nearest fabrication shop so they can produce a novel design which will delight the queen.  Annual parades and races show off all of them, and promote community spirit on this strange but peaceful planet.