Lily lost her first tooth and got $100 from the Tooth Fairy. Cam and Mitch are trying to convince her that the Tooth Fairy made a mistake and she should give the money back, but Lily wants to keep the money until Haley tells her this would almost certainly put her on Santa’s naughty list. Now Lily has to decide what she values more: $100 or Christmas presents.
See more: opportunity cost, rationality, tradeoffs
Economics of Modern Family 