Optimal Approximate Choice Designs for a Two-step Coffee Choice, Taste and Choice Again Experiment
研究消费者对咖啡的偏好，先做选择实验，再让受访者品尝两种咖啡后重复选择实验，提出基于近似设计理论和复合设计准则的异质性选择设计方法，并用面板混合Logit模型分析，结果验证了方法的有效性。
Abstract This work deals with consumers' preferences about coffee. Firstly, a choice experiment is performed on a sample of potential consumers. Following this, a sensory test involving the tasting of two varieties of coffee is carried out with the respondents, after which the same choice experiment is supplied to them again. An innovative approach for building heterogeneous choice designs is specifically developed for the case-study, based on approximate design theory and compound design criterion. Panel Mixed Logit models are used, thereby allowing for the inclusion of correlation among consumers' responses; choice-sets are supplied to a proportion of respondents according to optimal weights. The estimation results of the Panel Mixed Logit model are satisfactory, confirming the validity of the proposed approach.