2016 年 43 巻 2 号 p. 167-180
We propose an econometric two-stage model for category-level purchase and brand-level purchase which allows simultaneous brand purchase at the same time. The proposed model formulation is consistent with the traditional theory of consumer behavior, and the utility functions remain to be normally distributed. Such modeling approaches have not been found in existing econometric models. The simulation studies show the previously proposed related models can cause severe bias in predicting the future brand choices, while the proposed method can effectively predict them. Additionally in real data analysis, while the existing methods provided the parameter estimation results that were implausible, the proposed method provided the results that were plausible.