  This paper studies the equilibrium behavior of customers in the Geo/Geo/1
queueing system with multiple working vacations. The arriving customers decide
whether to join or to balk the queueing systems based on the information of the
queue length and the states of the server. In observable queues, partially
observable queues and unobservable queues three cases we obtain the equilibrium
balking strategies based on the reward-cost structure and socially optimal
strategies for all customers. Furthermore, we present some numerical
experiments to illustrate the effect of the information level on the
equilibrium behavior and to compare the customers' equilibrium and socially
optimal strategies.
