http://en.wikipedia.org/wiki/Keynesian_beauty_contest http://en.wikipedia.org/wiki/Keynesian_beauty_contest Related: The NPR podcast Planet Money recently held

http://en.wikipedia.org/wiki/Keynesian_beauty_contest http://en.wikipedia.org/wiki/Keynesian_beauty_contest Related: The NPR podcast Planet Money recently held a "contest" where you had to pick the number from 0 to 100 that would be the average of all guesses. If you assume everyone is rational (and everyone's estimate of each other's rationality, recursively) it should be 0; the actual answer was around 11.5.