Trust me: Communication and Competition in a Psychological Game

We study, both theoretically and experimentally, a communication game with and without seller competition and embed it in a psychological-game framework where players experience costs for lying, misleading others, and being disappointed. We derive the equilibrium predictions of this model, compare them to the setting without psychological payoffs, and test these predictions in a laboratory experiment, in which we induce both material and psychological payoffs. We find that the setting in which players have both material and psychological payoffs features more trade, trades goods of marginally better quality, and does so without welfare losses to either side of the market relative to the setting with material payoffs only. However, the introduction of competition counteracts this improvement and lowers welfare for both sides of the market. This happens due to a surge in dishonesty by sellers in the competitive setting and the buyers’ inability to detect this deception.