A new stochastic multidimensional unfolding model for the investigation of paired comparison consumer preference/choice data

This paper presents the development of a new stochastic multidimensional (scaling) unfolding (Coombs 1964) methodology which operates on paired comparison consumer preference or choice data and renders a spatial representation of both consumers and the products or brands they choose. Consumers are represented as ideal points and products as points in a T-dimensional space, where the Euclidean distance between the product points and the consumer ideal points provide information as to the utility of such products to these consumers. The econometric and psychometric literature concerning related models which also operate on such paired comparisons data is reviewed, and a technical description of the new methodology is provided. To illustrate the versatility of the model, a small application measuring consumer preference for several actual brands of over-the-counter analgesics, utilizingone of the optional reparametrized models, is described. Finally, future areas of further research are identified.