Experimental chats: opening the black box of group experiments

The problems of collective decision making and voting – as one of the models of aggregating individual to collective preferences – belong to the defining research questions of political science. In their early overview of experimental political science, Kinder and Palfrey highlight the flexibility of the experimental method to study different levels of aggregation and to explicitly address the problem of aggregation (Kinder and Palfrey, 1993). Indeed, voting and collective decision making has become a major field of experimental research, not only in political science (Palfrey, 2008; Wilson, 2007; McDermott, 2007) but also in the adjoining disciplines of behavioral economics (Schram, 2003) and social psychology (Moscovici and Zavalloni, 1969; Kerr et al., 1996). In his highly influential summary of the state-of-the-art in behavioral economics, Camerer (2003) listed group decision making as one of his top ten open research questions in experimental research. His argument was that the vast majority of experimental studies resorted to the game theoretic standard hypothesis of the irrelevance of the decision maker and therefore conducted experiments mainly with individuals as decision makers. Given the sufficient flexibility of the experimental Experimental Chats approach, Camerer suggests a promotion of collective decision experiments – also to produce facts in order to stimulate theoretical advancement. Since Camerer’s invitation, the already substantial stream of research appears to have sped up in progression (Cooper and Kagel, 2005).