What do Consumers Consider Before They Choose? Identification from Asymmetric Demand Responses
中文摘要
考虑集模型通过放宽消费者会考虑所有可选选项这一假设，对离散选择模型进行了推广。此前，要确定消费者考虑过哪些选项，要么需要调查数据，要么需要对属性如何影响考虑或效用施加限制。我们提供了另一种途径。在完全考虑模型中，选择概率满足一种类似于连续选择模型中斯勒茨基对称性的对称性质。在考虑集模型中，当特征变化扰动考虑过程时，这种对称性便不再成立。我们证明，可以从由此产生的非对称性中构造性地识别考虑概率。我们首先在考虑集已知的实验室实验中验证了这一方法，随后将该框架应用于研究美国联邦医疗保险D部分（Medicare Part D）中的一项“智能默认”政策；在该政策下，消费者会被自动重新分配至成本较低的处方药计划，同时可选择退出。完全考虑模型意味着，此类政策将不起作用，因为消费者会选择退出以避免转换成本。在允许存在疏忽（inattention）的情况下，我们发现，将所有消费者默认分配至成本较低的选项，平均而言产生的福利收益微乎其微；但仅将可节省至少300美元的消费者默认分配至此类选项，则会产生较大的福利收益。
Abstract
Abstract Consideration set models generalize discrete-choice models by relaxing the assumption that consumers consider all available options. Determining which options were considered has previously required either survey data or restrictions on how attributes affect consideration or utility. We provide an alternative route. In full-consideration models, choice probabilities satisfy a symmetry property analogous to Slutsky symmetry in continuous-choice models. This symmetry breaks down in consideration set models when changes in characteristics perturb consideration. We show that consideration probabilities are constructively identified from the resulting asymmetries. We validate our approach in a lab experiment where consideration sets are known and then apply our framework to study a “smart default” policy in Medicare Part D, wherein consumers are automatically reassigned to lower-cost prescription drug plans with the option of opting out. Full-consideration models imply that such a policy will be ineffective because consumers will opt out to avoid switching costs. Allowing for inattention, we find that defaulting all consumers to lower-cost options produces negligible welfare benefits on average, but defaulting only consumers who would save at least $300 produces large benefits.