Communication and Information in Games of Collective Decision: A Survey of Experimental Results1 César Martinelli Thomas R. Palfrey December 24, 2017 1Martinelli: Department of Economics, George Mason University. Email:
[email protected]. Palfrey: Division of the Humanities and Social Sciences, California Institute of Technology. Email:
[email protected]. 1 Introduction and overview Voting games and other collective decision situations pose particular challenges for game theory. Often, there is a plethora of Nash equilibria, which creates coordination problems, making it difficult for decision makers to reach the best equilibrium outcomes, or even any equilibrium outcome at all. In addition, voters often differ in their motivations and prefer- ences, which may include pro-social or anti-social elements, and this heterogeneity further clouds best response behavior. Even when there is repeated interaction, opportunities to learn about other voters’ motivations and plans are limited since often only aggregate information is available. Last but not least, side payments are often unavailable as a tool to price decisions or to provide compensation to losers and long term contracting is generally impossible. And yet, political behavior is not characterized in the real world by relentless chaos. Communication and other pre-play activities involving the acquisition and transmission of information across voters may to some extent be responsible for the degree of coordination commonly exhibited in collective decision environments. Laboratory experiments inspired by political situations seem uniquely qualified to throw light in the effects of pre-play ac- tivities on behavior and coordination in collective decision environments, since they allow the researcher a greater degree of control and observability of information acquisition and information flows among voters.