🤖 AI Summary
This paper investigates the strategic joining decisions of customers in an M/M/1 queue when observing the queue length incurs a private inspection cost: customers may join blindly, balk blindly, or pay to observe the state before deciding. We formulate this as a Bayesian game—first introducing explicit inspection costs into the queueing games framework to rigorously characterize the trade-off between information value and waiting cost. Through analytical derivation, we obtain a closed-form solution for the Nash equilibrium, prove its uniqueness, and establish necessary and sufficient conditions for existence, revealing a structured threshold policy. Results show that reducing inspection costs improves social welfare, albeit with diminishing returns; conversely, increasing the reward for joining enhances individual incentives but may induce excessive entry, degrading system efficiency. This work provides foundational theoretical support for information design and mechanism optimization in observable queueing systems.