EIP-1559
EIP-1559 was the Ethereum Improvement Proposal implemented in the London hard fork (August 2021) that reformed Ethereum's transaction fee mechanism. It replaced the first-price auction model with a hybrid base-fee-plus-tip system: each block has a protocol-determined base fee that adjusts up or down based on whether the previous block was above or below the 50% capacity target, and this base fee is burned (removed from ETH supply) rather than paid to the validator. Users additionally specify a priority fee (tip) paid to the proposer for inclusion. EIP-1559 made fees more predictable (the base fee is known in advance, unlike the blind first-price auction) and introduced a structural ETH burn mechanism that partially offsets new issuance. The MEV impact: the base fee burn reduces the value available for PGA-style gas bidding, but the priority fee still creates an inclusion market. EIP-1559 does not directly address MEV — PBS and proposer commitments were pursued as separate tracks.