Sunk costs and decision making Rajiv has plans to go to a play and already has a $50 nonrefundable, nonexchangeable, and nontransferable ticket. Now Simone, whom Rajiv has wanted to date for a long time, asks him to a concert. Rajiv would prefer to go to the concert with Simone and forgo the play, but he doesn't want to waste the $50 he spent on the play ticket. From the perspective of an economist, if Rajiv decides to go to the concert with Simone, what has he just done