A traveller wandering on an island inhabited entirely by cannibals comes upon a butcher shop. This shop specialised in human brains differentiated according to source. The sign in the shop read:
Artists’ Brains $9/lb Philosophers’ Brains $12/lb Scientists’ Brains $15/lb Economists’ Brains $19/lb

Upon reading the sign, the traveller noted, «My those economists’ brains must be popular!» To which the butcher replied, «Are you kidding! Do you have any idea how many economists you have to kill to get a pound of brains?!»