On Budget Balance of the Dynamic Pivot Mechanism

We modify the dynamic pivot mechanism of Bergemann and VAalimAaki (Econometrica, 2010) in such a way that lump-sum fees are collected from the players. We show that the modi?ed mechanism satis?es ex-ante budget balance as well as ex-post e¡¾ciency, periodic ex-post incentive compatibility, and periodic ex-post individual rationality, as long as the Markov chain representing the evolution of players' private information is irreducible and aperiodic and players are su¡¾ciently patient. We also show that the diverse preference assumption of Bergemann and VAalimAaki may preclude budget balance.