Self-regulation of an unobservable queue

We consider an unobservable M/M/1 queue where customers are homogeneous with respect to service valuation and cost per unit time of waiting. It is well known that left to themselves, in equilibrium, customers join the queue at a rate higher than is socially optimal. Hence, regulation schemes, under which the resulting equilibrium joining rate coincides with the socially optimal one, should be considered. We suggest a classification of regulation schemes based on a few desired properties and use it to classify schemes from the existing literature. To the best of our knowledge, none of the existing schemes possesses all of the properties, and in this paper we suggest such a scheme. Its novelty is in assigning random priorities to customers, prior to their decision whether to join or balk. We also introduce variations of this regulation scheme as well as others that are also based on randomization.