We experimentally study how mutual payoff information affects strategic play. Subjects play the Prisoner's Dilemma or Stag Hunt game against randomly re-matched opponents under two information treatments. In our partial-information treatment, subjects are shown only their own payoff structure, while in our full-information treatment they are shown both their own and their opponent's payoff structure. In both treatments, they receive feedback on their opponent's action after each round. We find that mutual payoff information initially facilitates reaching the socially optimal outcome in both games. Play in the Prisoner's Dilemma converges toward the unique Nash equilibrium of the game under both information treatments, while in the Stag Hunt mutual payoff information has a substantial impact on play and equilibrium selection in all rounds of the game. Belief-learning model estimations and simulations suggest these effects are driven by both initial play and the way subjects learn.
