Search Among Queues Under Quality Differentiation
研究了客户在面临众多质量不同、拥挤的服务提供商时，如何通过成本性顺序搜索来权衡质量与可用性，并发现降低搜索成本或客户到达率可能增加平均等待时间，甚至降低客户福利。
Customers looking for service providers often face search frictions and have to trade off quality and availability. To understand customers’ search behavior when they are confronted with a large collection of vertically differentiated, congested service providers, we build a model in which arriving customers conduct a costly sequential search to resolve uncertainty about service providers’ quality and queue length and select one to join by optimal stopping rules. Customers search, in part, because of variations in waiting time across service providers, which, in turn, is determined by the search behavior of customers. Thus, an equilibrium emerges. We characterize customers’ equilibrium search/join behavior in a mean field model as the number of service providers grows large. We find that reducing either the search cost or customer arrival rate may increase the average waiting time in the system as customers substitute toward high-quality service providers. Moreover, with lower search costs, the improved quality obtained by customers may not make up for the prolonged wait, therefore degrading the average search reward and, more importantly, decreasing customer welfare; when customers search, their welfare can even be lower than if they are not allowed to search at all. This paper was accepted by Gad Allon, operations management.