Let the Dummy Talk!- Unilateral Communication and Discrimination inThree-Person Dictator Experiments -

To explain why pre-play communication increases cooperation in games,one refers to a) strategic causes such as efficient communication or reputationeffects, and b) changes in the utilities due to social processes. Hithertoexperimental support for both explanations is mixed and confounded. Ourexperimental design eliminates all strategic factors and allows to focus onthe effects of communication processes. We clearly find social effects, butnone of revealed anonymity or salient communication. The social processesinvoked are very heterogeneous but not irregular for different communicators.