CryptoSlate
Aug. 26 Blockchain.com data showed Bitcoin block 964,120 paying miners 0.0077 BTC in fees while block 964,121 paid 0.0536 BTC, a nearly seven-fold swing in adjacent blocks. A July 2026 NBER working paper argues that kind of fee gap is where the security-budget risk lives, not aggregate fee revenue. Authors Fabian Schär, Dario Thürkauf, and David Yermack used 2017-2025 data and report that larger fee differences between neighboring blocks correlate with more competing blocks at the same height and longer waits for the next. The result is observational, not causal: it describes a network-level relationship while leaving individual miner motives unresolved.
Why it matters
Bitcoin currently pays miners a fixed 3.125 BTC subsidy per block plus whatever fees the block includes. Each subsidy cut shifts more weight onto fees, but the new NBER analysis reframes the security question around distribution rather than totals. A miner rebuilding an earlier height to capture its fees has more reason to do so when the prior block's prize greatly exceeds the expected reward for extending the current tip. The attempt starts behind the accepted tip, so the odds depend on hash-rate share, propagation, and how other miners react.
Market impact
The paper gives wallets, miners, and protocol developers a measurable signal, but the structural defenses remain partly incomplete. Bitcoin Optech notes that BIP 326, an anti-fee-sniping draft using nLockTime or nSequence, depends on consistent wallet adoption to shrink the available prize. An open April 2026 Bitcoin Core issue documents uneven application: the send RPC and GUI wallet set nLockTime near the current block height, while createrawtransaction and walletcreatefundedpsbt default to zero. Four signals to watch before the next subsidy cut are adjacent-block fee gaps, competing-block frequency, immediate next-block timing after a high-fee block, and lock-field coverage across transaction-creation paths.
Frequently asked questions
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What did the NBER working paper find about Bitcoin block fees?
The paper, by Fabian Schär, Dario Thürkauf, and David Yermack, found that larger fee gaps between adjacent Bitcoin blocks correlate with more competing blocks at the same height and longer waits for the next block. The result is observational, not causal.
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What is fee-sniping in Bitcoin mining?
Fee-sniping is when a miner attempts to recreate a valuable prior block to claim its fees and extend an alternative chain. The option becomes more profitable when the prior block's fees greatly exceed the expected reward for extending the current tip.
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How much do fees currently contribute to Bitcoin miner revenue?
A Glassnode measure put fees at about 0.70% of miner revenue on Aug. 26, 2026, while a BTC.network weekly reading for Aug. 14-21 calculated a 0.67% share. Both snapshots place fees below 1% of miner revenue.
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What is BIP 326 and does it solve fee-sniping?
BIP 326 is a draft informational proposal describing anti-fee-sniping behavior for Taproot transactions using nLockTime or nSequence. Its effectiveness depends on consistent wallet adoption, and an open April 2026 Bitcoin Core issue documents uneven application across transaction-creation paths.
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What signals should users watch for fee-sniping risk?
Four signals identified by the paper: adjacent-block fee gaps, competing-block frequency at the same height, immediate next-block timing after a high-fee block, and lock-field coverage across transaction-creation paths.
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