Three essays on conjoint analysis: optimal design and estimation of endogenous consideration sets
- Autores: Agata Leszkiewicz
- Directores de la Tesis: Mercedes Esteban Bravo (dir. tes.), José Manuel Vidal Sanz (dir. tes.)
- Lectura: En la Universidad Carlos III de Madrid ( España ) en 2014
- Idioma: inglés
- Tribunal Calificador de la Tesis: Francisco Javier Prieto Fernández (presid.), Oded Netzer (secret.), Gilles Laurent (voc.)
- Materias:
- Enlaces
- Tesis en acceso abierto en: e-Archivo
- Resumen
Over many years conjoint analysis has become the favourite tool among marketing practitioners and scholars for learning consumer preferences towards new products or services. Its wide acceptance is substantiated by the high validity of conjoint results in numerous successful implementations among a variety of industries and applications. Additionally, this experimental method elicits respondents’ preference information in a natural and effective way. One of the main challenges in conjoint analysis is to efficiently estimate consumer preferences towards more and more complex products from a relatively small sample of observations because respondent’s wear-out contaminates the data quality. Therefore the choice of sample products to be evaluated by the respondent (the design) is as much as relevant as the efficient estimation. This thesis contributes to both research areas, focusing on the optimal design of experiments (essay one and two) and the estimation of random consideration sets (essay three). Each of the essays addresses relevant research gaps and can be of interest to both marketing managers as well as academicians. The main contributions of this thesis can be summarized as follows: • The first essay proposes a general flexible approach to build optimal designs for linear conjoint models. We do not compute good designs, but the best ones according to the size (trace or determinant) of the information matrix of the associated estimators. Additionally, we propose the solution to the problem of repeated stimuli in optimal designs obtained by numerical methods. In most of comparative examples our approach is faster than the existing software for Conjoint Analysis, while achieving the same efficiency of designs. This is an important quality for the applications in an online context. This approach is also more flexible than traditional design methodology: it handles continuous, discrete and mixed attribute types. We demonstrate the suitability of this approach for conjoint analysis with rank data and ratings (a case of an individual respondent and a panel). Under certain assumptions this approach can also be applied in the context of discrete choice experiments. • In the essay 2 we propose a novel method to construct robust efficient designs for conjoint iii experiments, where design optimization is more problematic, because the covariance matrix depends on the unknown parameter. In fact this occurs in many nonlinear models commonly considered in conjoint analysis literature, including the preferred choice-based conjoint analysis. In such cases the researcher is forced to make strong assumptions about unknown parameters and to implement an experimental design not knowing its true efficiency. We propose a solution to this puzzle, which is robust even if we do not have a good prior guess about consumer preferences. We demonstrate that benchmark designs perform well only if the assumed parameter is close to true values, which is rarely the case, otherwise there is no need to implement the experiment. On the other hand, our worst-case designs perform well under a variety of scenarios and are more robust to misspecification of parameters. • Essay 3 contributes with a method to estimate consideration sets which are endogenous to respondent preferences. Consideration sets arise when consumers use decision rules to simplify difficult choices, for example when evaluating a wide assortment of complex products. This happens because rationally bounded respondents often skip potentially interesting options, for example due to lack of information (brand unawareness), perceptual limitations (low attention or low salience), or halo effect. Research in consumer behaviour established that consumers choose in two stages: first they screen off products whose attributes do not satisfy certain criteria, and then select the best alternative according to their preference order (over the considered options). Traditional CA focuses on the second step, but more recently methods incorporating both steps were developed. However, they are always considered to be independent, while the halo effect clearly leads to endogeneity. If the cognitive process is influenced by the overall affective impression of the product, we cannot assume that the screening-off is independent from the evaluative step. To test this behavior we conduct an online experiment of lunch menu entrees using Amazon MTurk sample.
