A Purely Posted-Price Transaction Fee Mechanism for Leaderless Blockchains

Most leading blockchains currently rely on users bidding for block space through first-price auctions, resulting in volatile and unpredictable transaction fees. As stability and predictability of transaction fees are fundamental to improve user experience, various projects have integrated posted-price components to their fee structure. In this work, we propose a purely posted-price mechanism, without an auction component, designed for implementation in leaderless blockchains, especially suited for protocols that use committees in the process of block issuance.In committees or other leaderless models, validators may not have dictatorial control over block content, contrary to the leader-based approach adopted in most popular blockchains. Our work provides a model for leaderless blockchains and proposes an auction-free mechanism for setting transaction fees. We then analyse its properties following an established framework for evaluation of transaction fee mechanisms. Additionally, we compare our proposal with Ethereum’s EIP-1559 through simulations, revealing that, despite a marginal increase in transaction processing time, the results showcase a substantial decrease in costs and improvements in the stability and predictability of transaction fees.