A solution for the multiple equilibrium problem in mechanism design

In implementation theory, it does not matter from the theoretical viewpoint that the designed mechanism has multiple equilibria, since those equilibrium outcomes coincide with the social goal by the definition of implementation. However, when those mechanisms are used in practice, the "equilibrium coordination problem" arises, i.e., how do agents decide which equilibrium to choose among those equilibria. Direct revelation mechanisms, which prevail recently, are simple enough to have multiple equilibria, so it is an important problem to solve the equilibrium coordination problem. This study shows that in a direct revelation mechanism, the truth-telling equilibrium tends to be selected among multiple equilibria by economic experiments. It turns out that if a mechanism with multiple equilibria has the truth-telling equilibrium, the equilibrium coordination problem could be resolve.