The ethicists and the game theorists
A bunch of game theorists and a bunch of ethicists are travelling on a train to a conference. As they purchase the tickets, the game theorists all purchase a ticket, while the ethicists collectively buy only one. When the ticket inspectors comes on the train, all the ethicists crowd into a toilet, and when the inspector knocks on the door, they slide one ticket out.
Hey, think the game theorists, this is a winning strategy, so on the return visit they buy one ticket for all of them. However, the ethicists don't buy any. Bemused by this, the game theorists reflect that they have a winning strategy anyway, no matter how good the ethicists' strategy might be, so when the inspector enters the carriage, they all crowd into one of the toilets.
And then one of the ethicists knocks on their door and calls out "tickets please".
This page was last updated July 1, 2006.