Compare the following:
Situation A: You have won two tickets (that would sell for $50 each) to a concert for free in a radio contest, but today, the day of the show, you find you would rather do something other than attend.
Situation B: You have purchased two tickets to a concert for $50 each, but today, the day of the show, you find you would rather do something other than attend.
Would you be more likely to go to the concert anyway in Situation B than A? I think most people would. And yet it seems to violate "economic rationality" -- the $100 is gone, and therefore shouldn't influence one's choice: "No sense crying over spilled milk."
I've come up with two ways to reconcile the typical choice with economic rationality. Any ideas out there?
EDIT: Fixed the problems Bob noted.