On the costly voting model: the mean rule

In this paper, we study a model in which a policy is chosen by a group of people through the formation of a committee. Attending the committee is costly, and each person decides whether to take part in it or not. Our work complements Osborne, Rosenthal and Turner (2000) since we allow various types of costs. We work with the mean compromise function, and we do not restrict the distribution of the favourite policy of the group members. Under these assumptions, we establish the existence of pure Nash equilibrium and show that, in comparison to the case of the median compromise function, the outcome of the committee’s work is less random and is not likely to be extreme. In the case of constant costs of participation, we show that when the costs increase, the size of the equilibrium committee decreases and the spread of the outcomes increases.