Evidence games: Lying aversion and commitment

The voluntary disclosure literature suggests that in evidence games, where the informed sender chooses which pieces of evidence to disclose to the uninformed receiver who determines their payoff, commitment does not matter, as there is a theoretical equivalence between the optimal mechanism and the game equilibrium outcomes. In this paper, we experimentally investigate whether the optimal mechanism and the game equilibrium outcomes coincide in a simple evidence game. Contrary to the theoretical equivalence, our results indicate that outcomes diverge and that commitment changes the outcomes. Our experimental results are in line with the predictions of a model that accounts for lying-averse agents.