Foresee the Next Line: Customer Strategies and Information Disclosure in Tandem Queues

The paper “Foresee the Next Line: Customer Strategies and Information Disclosure in Tandem Queues” examines how queue-length information affects customer behavior in multistage services, such as visiting the Apple Store—where you first wait to check in and then wait for a technician. It focuses on a two-stage tandem queue: an admission queue followed by a treatment queue. In the fully observable model, customers see both queues before entering the system, and the equilibrium joining strategy depends on the exact queue lengths rather than just their sum. In the partially observable model—which is more common in practice—customers initially see only the first queue and find the second queue’s length after completing the first stage. In this case, a threshold equilibrium emerges. Comparing models, the partially observable version generally yields higher throughput but lower social welfare. Results combine exact analysis in special regimes with extensive numerical computations.