Interdependent Preferences and Groups of Agents

An individual's preferences are assumed to be malleable and may be influenced by the preferences of others. Mutual interaction among individuals whose preferences are interdependent powers a dynamic process in which preference profiles evolve over time. Two formulations of the dynamic process are presented. One is an abstract model in which the iteration of a mapping from profiles to profiles defines a discrete time dynamic process; the other is a linear discrete time process specified in more detail. Examples motivate the model and illustrate its application. Conditions are given for the existence of a stable preference profile - a rest point of the dynamic process. A stable profile is naturally associated with a division, not in general unique, of the set of agents into subgroups with property that preference interdependencies within a subgroup are "stronger" than those across subgroups. The conventional case in which each agent's preference relation is exogenously given is, in this model, the special case where each subgroup consists of just one agent.