Success and failure in complex collective decision making: The Random Exchange Decide model

We present the Random Exchange model, an extension of the bilateral exchange model of collective decision-making of Stokman and Van Oosten. Compared to more elementary models, the Random Exchange model generates predictions of the process leading to the outcome and enhances understanding of deadlock or difficulties in the negotiation process. After explaining its logic, the Random Exchange model is applied to collective decision-making in the international setting of two climate agreements, chaired by the European Union; the 2009 Climate Conference of Parties (COP) in Copenhagen, and the 2015 COP in Paris. The applications show how Random Exchange model not only may be used to predict collective decision-making outcomes but also deadlock when powerful actors attach high relative saliences to at least two issues on which they have opposite positions.