Have two subjects play matching pennies. They will face each other but separated by a one-way mirror. Only one subject will be able to see the other’s face. He can only see the face, not anything below the chin.
Each subject selects his action by touching a screen. Touch the screen to the West to play Heads, touch the screen on the East to play Tails. (East-West rather than left-right so that my Tails screen is on the same side as your Tails screen. This makes it easier to keep track.)
You have to touch a lighted region of the screen in order to have your move registered and the lighted region is moving around the screen. This is going to require you to look at the screen you want to touch. But you can look in one direction and then the other and touch only the screen you want. Your hands are not visible to the other subject.
How much more money is earned by the player who can see the other’s eyes?
(Conversation with Adriana Lleras-Muney)