Mechanism design theory strongly relies on the concept of Nash equilibrium. However, studies of experimental games show … of the most influential benchmarks of mechanism design theory, the expected externality mechanism (DÁspremont, Gerard …

of congestion externalities. We show in this paper that the resulting equilibrium may not be unique for particular models … of congestion, including the first-best solution for the conventional Vickrey's bottleneck model. This can have … bottleneck model if the buying and selling of credits with a bank is allowed, against a pre-determined price. Credits are then …