Modeling Group Preferences Using a Decompositional Preference Approach

This article examines an extension of the decompositional, conjoint, or stated-preference approach to model group decisions. In the conventional approach, only one member is chosen to be the group's representative and provide answers for the group as a whole. In this study, all group members are brought together and asked to jointly complete a conjoint preference experiment. The hypothesis is tested that this joint group approach predicts group behavior better than the conventional approach with representatives. The paper presents the estimated part-worth utilities of the group model and compares preference structures of individual group members and groups. Finally, group preference models are tested to determine whether they outperform representative-based preference models in terms of the ability to correctly predict the group preferences for new alternatives. These analyses are performed in the context of residential preferences of co-ops, which are groups of young people, usually not partners, who live together in owner-occupied houses.