The incentive-compatibility properties of blockchain transaction fee mechanisms have been investigated with *passive* block producers that are motivated purely by the net rewards earned at the consensus layer. This paper introduces a model of *active* block producers that have their own private valuations for blocks (representing, for example, additional value derived from the application layer). The block producer surplus in our model can be interpreted as one of the more common colloquial meanings of the term ``MEV.'' The main results of this paper show that transaction fee mechanism design is fundamentally more difficult with active block producers than with passive ones: with active block producers, no non-trivial or approximately welfare-maximizing transaction fee mechanism can be incentive-compatible for both users and block producers. These results can be interpreted as a mathematical justification for the current interest in augmenting transaction fee mechanisms with additional components such as order flow auctions, block producer competition, trusted hardware, or cryptographic techniques.

翻译：区块链交易费用机制的激励相容性已在被动区块生产者（仅受共识层净奖励驱动）的框架下得到研究。本文提出了一种主动区块生产者模型，该类生产者对区块具有私有估值（例如代表应用层产生的附加价值）。该模型中区块生产者盈余可被解释为术语"MEV"最常见的通俗含义之一。本文的主要结果表明，与被动区块生产者相比，主动区块生产者情境下的交易费用机制设计面临根本性困难：在存在主动区块生产者时，任何非平凡或近似福利最大化的交易费用机制均无法同时实现用户与区块生产者的激励相容。这些结论可作为当前通过订单流拍卖、区块生产者竞争、可信硬件或密码学技术等附加组件增强交易费用机制的必要性提供数学依据。