This paper studies pricing and incentive issues in the assignment of c
ustomers to servers in a system that suffers congestion effects. When
customers have private information about their waiting costs, a system
administrator who wishes to maximize steady-sate net benefits per uni
t of time (i.e. total benefits from service minus total waiting costs)
may do so using a pricing and routing scheme that is incentive compat
ible; that is, no customer has any incentive to reveal his private inf
ormation untruthfully. When the system administrator wants to maximixe
toll revenue, the optimal scheme involves higher tolls, and hence low
er congestion, than is socially optimal.