Heterogeneous Consumer Search and Social Learning: Empirical Studies

这两个研究项目探讨了消费者需求的两个方面，这些方面可能对市场效率产生重要影响：异质消费者搜索和社会学习。这两个项目都使用了非常适合要解决的问题的新数据集。 第一个项目审查消费者在零售市场寻找处方药的性质和强度。处方药的零售价格即使在同一个当地市场内也会在不同的药店之间有很大的差异，之前的研究表明，价格分散的模式与消费者搜索的经济模型是一致的：例如，与一次性药物相比，重复购买的药物（价格商店的激励最强）的价格往往不那么分散。该项目将调查两个小城市20多万处方药购买的数据。对于每笔交易，数据识别实际价格和支付类型（现金，第三方保险或医疗补助）以及处方特征。由于所有竞争药店的价格和数量数据都是可用的，因此在观察到的市场份额对相对价格差异的敏感性中，可以发现有关消费者搜索程度的信息。这项研究将为有关价格分散和消费者搜索的重要问题提供答案：这些市场中的消费者搜索有多激烈（即，有多少消费者在购买前选择价格商店？）药物搜索强度的变化是否与消费者搜索的经济理论的预测一致？估计的搜索强度揭示了搜索成本的潜在分布情况？ 第二个项目涉及社会学习对个人选择健康保险计划的影响。大公司的员工通常从雇主赞助的一组健康保险选项中选择;由于健康计划的选择可能是一个复杂的决定，个人可能会尝试从同事那里了解计划的相对质量-通过直接沟通或基于观察到的选择进行推断。这种学习的原因和后果已经在理论文献中得到了形式化的讨论，但是很少有人努力去实证地衡量社会学习的重要性。本研究将使用一所主要大学的员工的健康计划选择的数据，以获得社会学习的影响的定量估计。有关员工的人口统计信息，特别是他们工作的部门，将用于确定学习发生的沟通渠道。简单地说，如果个人的决定在部门内比在部门间更相似，这可以被认为是学习或“羊群”效应的暗示。这是该项目的主要方法的基本思想，即估计健康计划选择的计量经济学模型，其中包括邻居的决定对个人决定的影响。实证结果将产生重要的见解学习的性质和程度，需求分析和健康计划竞争的影响，以及由于模仿行为的潜在福利损失的幅度。

This pair of research projects explores two aspects of consumer demand that can have important implications for market efficiency: heterogeneous consumer search and social learning. Both projects make use of new datasets that are uniquely well-suited for the questions to be addressed. The first project examines the nature and intensity of consumer search in retail markets for prescription drugs. Retail prices for prescription drugs vary widely across pharmacies even within the same local market, and previous research has shown that patterns in price dispersion are consistent with economic models of consumer search: for instance, prices tend to be much less disperse for medications that are purchased repeatedly (for which the incentives to price-shop are strongest) than for one-time medications. This project will investigate data on over 200,000 prescription purchases in two small cities. For each transaction, the data identify the actual price and payment type (cash, third-party insurance, or Medicaid) as well as prescription characteristics. Since data are available on prices and quantities at all competing pharmacies, information about the extent of consumer search is revealed in the observed sensitivity of market shares to relative price differences. The research will provide answers to important questions about price dispersion and consumer search: How intense is consumer search in these markets (i.e., what fraction of consumers chooses to price-shop before purchasing?) Is variation in search intensity across drugs consistent with the predictions of economic theories of consumer search? What do the estimated search intensities reveal about the underlying distribution of search costs? The second project concerns the impact of social learning on individuals' choices of health insurance plans. Employees of large firms typically choose from a set of health insurance options sponsored by their employer; since the choice of a health plan can be a complex decision, individuals may attempt to learn about plans' relative qualities from co-workers-either through direct communication or by drawing inferences based observed choices. The causes and consequences of this kind of learning have been formalized and discussed in the theoretical literature, but little effort has been made to measure the importance of social learning empirically. This study will use data on the health plan choices of the employees of a major university to obtain quantitative estimates of the effects of social learning. Information about employee demographics--and especially the departments in which they work-will be used in identifying the communication channels through which learning occurs. Stated very simply, if individuals' decisions are significantly more similar within departments than they are across departments, this can be taken as suggestive of a learning or "herding" effect. This is the basic idea underlying the project's principal approach, which is to estimate an econometric model of health plan choice that incorporates the influence of neighbors' decisions on the decision of the individual. The empirical results will yield important insights into the nature and extent of learning, the implications for demand analysis and health plan competition, and the magnitude of potential welfare losses due to imitative behavior.