Segmentation-based competitive analysis with MULTICLUS and topology representing networks

Two neural network approaches, Kohonen's self-organizing (feature) map (SOM) and the topology representing network (TRN) of Martinetz and Schulten are employed in the context of competitive market structuring and segmentation analysis. In an empirical study using brands preferences derived from household panel data, we compare the SOM and TRN approach to MULTICLUS, a parametric latent vector multi-dimensional scaling (MDS) model approach which also simultaneously solves the market structuring and segmentation problem. Our empirical analysis shows several bene"ts and shortcomings of the three methodologies under investigation. As compared to MULTICLUS, we "nd that the nonparametric neural network approaches show a higher robustness against any kind of data preprocessing and a higher stability of partitioning results. As compared to SOM, we "nd advantages of TRN which uses a more #exible concept of adjacency structure. In TRN, no rigid grid of units must be prespeci"ed. A further advantage of TRN lies in the possibility to exploit the information of the neighborhood graph for adjacent prototypes which supports ex-post decisions about the segment con"guration at both the micro and the macro level. However, SOM and TRN also have some drawbacks as compared to MULTICLUS. The network approaches are, for instance, not directly accessible to inferential statistics. Our empirical study indicates that especially TRN may represent a useful expansion of the marketing analyst's tool box.