Briefing
The foundational challenge in blockchain economics is designing a Transaction Fee Mechanism (TFM) that remains Incentive-Compatible (IC) when block producers are active, privately valuing Maximal Extractable Value (MEV). This research proves that a fully welfare-maximizing TFM is impossible under these conditions. The breakthrough is the SAKA mechanism , a deterministic, auction-based TFM that formally incorporates the searcher role as an “MEV oracle.” SAKA achieves Dominant-Strategy Incentive-Compatibility (DSIC) for users and searchers, alongside Block Producer Incentive-Compatibility (BPIC). The single most important implication is that protocol-native, game-theoretic mechanisms can fundamentally restructure the block production market to ensure economic fairness and predictability, even in the presence of MEV.
Context
Prior Transaction Fee Mechanism (TFM) design theory, including foundational work on EIP-1559, modeled block producers as passive agents motivated solely by net transaction fees. This established framework failed to account for the reality of MEV, which is the block producer’s private, application-layer value. The resulting theoretical limitation was a proven impossibility ∞ no non-trivial TFM could be simultaneously welfare-maximizing and incentive-compatible for both users and active block producers. This impossibility is a mathematical justification for augmenting TFMs with additional components to manage MEV.
Analysis
The SAKA mechanism resolves the impossibility by formalizing the MEV supply chain into the TFM itself. The model introduces a multi-agent auction distinguishing between users, searchers, and the proposer (block producer). Users submit bids for transaction inclusion, and searchers submit bids for the right to execute MEV-generating transaction bundles. The key innovation is that the searcher’s winning bid effectively acts as an “MEV oracle,” revealing the transaction’s true economic value to the protocol.
The mechanism then uses this revealed value to calculate the final transaction fee, ensuring that all participants ∞ users, searchers, and the block producer ∞ are incentivized to bid truthfully. This strategy-proof design restores the critical property of incentive-compatibility across the entire block construction ecosystem.
Parameters
- Welfare Guarantee ∞ Roughly 50% of the maximum-possible social welfare. The mechanism is proven to guarantee this level of efficiency when transaction sizes are small relative to block capacity.
- Impossibility Bound ∞ No deterministic, IC, sybil-proof TFM can guarantee more than 50% of the maximum-possible welfare, demonstrating the optimality of SAKA’s approximation.
- Key Properties ∞ The mechanism is Dominant-Strategy Incentive-Compatible (DSIC) for both users and searchers, and Block Producer Incentive-Compatible (BPIC).
Outlook
This research shifts the focus from purely mitigating MEV to formally integrating it into the core protocol design through mechanism engineering. Future work will involve extending SAKA to handle more complex scenarios, such as collusion between users and searchers, and exploring its implementation in shared sequencer environments. The theory unlocks a pathway for future blockchain architectures to achieve predictable transaction costs and equitable value distribution by designing the MEV market into the consensus layer, thereby enhancing the overall stability and fairness of decentralized systems in the next three to five years.
Verdict
The SAKA mechanism provides the foundational game-theoretic blueprint for designing economically robust, incentive-compatible transaction ordering protocols in a world dominated by Maximal Extractable Value.
