Proposer Dilemma

Definition ∞ The Proposer Dilemma describes a conflict of interest faced by a blockchain block proposer, typically a miner or validator, when deciding which transactions to include and in what order. This dilemma arises because the proposer can prioritize transactions that yield higher fees or allow for profitable arbitrage opportunities. Such decisions can impact transaction fairness and network efficiency. It presents a challenge to the ideal of neutral block production.
Context ∞ News and academic discussions frequently address the Proposer Dilemma in the context of miner extractable value (MEV) and its implications for blockchain security. The pursuit of maximum profit by proposers can lead to practices like front-running or transaction reordering. Solutions to mitigate this dilemma are actively researched and developed by protocol designers. Its presence highlights economic incentives within decentralized systems.