Abstract
In this paper it is attempted to identify more general group utility functions based on the concept of convex dependence, which is an extended concept of utility independence in multiattribute utility theory. Here the number of the member in the group is assumed to be two. It is shown that the convex dependence could play an important role in the group decision or societal decision, since under the concept of convex dependence it is possible for each individual (member of the group) to assess the different preference structures depending upon the utility level of the other individual. These preference structures can be expressed as the conditional normalized utility functions which are expected to be assessed by each individual from the standpoint of attaining better society. The group utility function is then identified by aggregating the conditional normalized group utility functions of the individuals where the existence of a benevolent dictator is postulated.
