In the film A Beautiful Mind about John Nash, there is a scene which purports to dramatize the moment in which Nash developed his idea for Nash equilibrium.  He and three mathematician buddies are in a bar (here I might have already jumped to the conclusion that the story is bogus, but I just got back from Princeton and I can confirm that there is a bar there.)  There are four brunettes and a blonde and the four mathematicians are scheming about who will go home with the blonde.  Nash proposes that the solution to their problem is that none of them go for the blonde.

Let’s go to the video.

Of course this is not a Nash equilibrium (also it is inefficient so it cannot be a dramatization of Nash’s bargaining paper either.)  However, this makes it the ideal teaching tool.

  1. This game has multiple equilibria with different distributional consequences.
  2. The characters talk before playing so its a good springboard for discussion of how pre-play communication should or should not lead to equilibrium.
  3. One of the other mathematicians actually reveals that he understands the game better than Nash does when he accuses Nash of trying to send them off course so that Nash can swoop in on the blonde.
  4. Showing what isn’t a Nash equilibrium is the best way to illustrate what it takes to be a Nash equilibrium.
  5. It has the requisite sex to make it fun for undergraduates.