A Shut Mouth Catches No Flies: Consideration of Issues and Voting

We study collective decision-making procedures involving the formation of an agenda of issues and the subsequent vote on the position for each issue on the agenda. Issues that are not on the agenda remain unsettled. We use a protocol-free equilibrium concept introduced by Dutta et al. (2004) and show that in equilibrium, and under general conditions, any subset of issues may be excluded from the agenda in equilibrium whenever the voting rule belongs to one of two prominent families. What is voted upon and what is not depends on the voters preferences in a subtle manner, suggesting a high degree of instability. We also discuss further conditions under which this “anything goes” result may be qualified. In particular, we study those cases where all issues will be put in the agenda.