August 1, 2010
We consider a dynamic auction environment with a long-lived seller and short-lived buyers mediated by a third party. A mediator has incomplete information about traders' values and selects an auction mechanism to maximize her expected revenue. We characterize mediator-optimal mechanisms and show that an optimal mechanism has a simple implementation as a Vickrey auction with a reserve price where the seller pays to the mediator only a fixed percentage from the closing price.
J.E.L classification codes: C73, D44, D82
Keywords:Optimal mechanism, Vickrey auction, Mediator