With the emergence of Miner Extractable Value (MEV), block construction markets on blockchains have evolved into a competitive arena. Following Ethereum's transition from Proof of Work (PoW) to Proof of Stake (PoS), the Proposer Builder Separation (PBS) mechanism has emerged as the dominant force in the Ethereum block construction market. This paper presents an in-depth longitudinal study of the Ethereum block construction market, spanning from the introduction of PoS and PBS in September 2022 to May 2023. We analyze the market shares of builders and relays, their temporal changes, and the financial dynamics within the PBS system, including payments among builders and block proposers -- commonly referred to as bribes. We introduce an MEV-time law quantifying the expected MEV revenue wrt. the time elapsed since the last proposed block. We provide empirical evidence that moments of crisis (e.g. the FTX collapse, USDC stablecoin de-peg) coincide with significant spikes in MEV payments compared to the baseline. Despite the intention of the PBS architecture to enhance decentralization by separating actor roles, it remains unclear whether its design is optimal. Implicit trust assumptions and conflicts of interest may benefit particular parties and foster the need for vertical integration. MEV-Boost was explicitly designed to foster decentralization, causing the side effect of enabling risk-free sandwich extraction from unsuspecting users, potentially raising concerns for regulators.

翻译：随着矿工可提取价值（MEV）的出现，区块链上的区块构建市场已演变为竞争激烈的领域。继以太坊从工作量证明（PoW）向权益证明（PoS）过渡后，提议者-构建者分离（PBS）机制已成为以太坊区块构建市场的主导力量。本文对以太坊区块构建市场进行了深入的纵向研究，时间跨度从2022年9月PoS和PBS引入至2023年5月。我们分析了构建者和中继的市场份额、其时间变化以及PBS系统内的财务动态，包括构建者与区块提议者之间的支付——通常称为贿赂。我们提出了一条MEV-时间定律，用于量化预期MEV收益与自上次提议区块以来经过时间的关系。我们提供了实证证据，表明危机时刻（例如FTX崩盘、USDC稳定币脱钩）与基线水平相比，MEV支付显著飙升。尽管PBS架构旨在通过分离参与者角色来增强去中心化，但其设计是否最优仍不明朗。隐式的信任假设和利益冲突可能使特定方受益，并催生垂直整合的需求。MEV-Boost虽明确旨在促进去中心化，但副作用是使无防备用户遭受无风险的三明治提取，这可能会引发监管机构的担忧。