Bitcoin’s block subsidy drops to 3.125 BTC today. In 2140, it hits zero. Transaction fees on the base layer currently average 0.0001 BTC per block. Simple math: 0.0001 * 144 blocks per day equals 0.0144 BTC daily. That’s roughly $400 at current prices—against a network securing over $1 trillion in value. Math doesn’t lie. The numbers expose a structural gap that no amount of narrative engineering can patch.
Peter Todd sees this gap and proposes a permanent block reward—a small, never-ending issuance to keep miners paid once the last new Bitcoin arrives. Adam Back reads the argument as a trap dressed up as engineering. He points to BIP-110, the failed 2026 soft fork that tried to filter non-payment data out of blocks, as the model for how these campaigns get sold. Back warned that trick is finding ways to trigger and rally people to a dangerously inadvisable cause with simple though false narratives. The pattern is clear: frame a real technical problem, then offer a solution that changes the consensus rules for a specific interest group.
Context
Bitcoin pays miners in two ways. Block subsidies mint new coins, and transaction fees ride along with each block. The subsidy is halved roughly every four years. After 2140, fees alone must carry security. Todd argues fee revenue swings too wildly to hold the chain together. Miners would be incentivized to reorganize the chain and re-mine fat-fee blocks rather than build forward. A fixed reward, he says, kills that pull.
His case leans on lost coins. Todd models supply against a loss rate and finds it settles at a ceiling, because coins vanish as fast as fresh ones appear. Therefore, he frames tail emission as a stabilizer, not inflation. He has pointed to Monero, which already runs a small permanent reward. Its apparent inflation rate keeps sliding toward zero. The Bitcoin++ conference account resurfaced his talk on the topic this week, reopening the argument.
Back rejects the framing outright. He points to BIP-110, the contentious 2026 soft fork that tried to filter non-payment data out of blocks. That fork died after two blocks with miner support near 2.53% against a 55% bar. Back had predicted the stall weeks earlier. Bitcoin commentator Trey Sellers made the parallel explicit, writing that a supply-schedule fork would fail as hard as BIP-110, if not harder. Michael Saylor raised a related worry, warning about protocol neutrality whenever consensus rules bend to one camp.
One difference cuts against Todd. BIP-110 asked for a soft fork, which needs only miner cooperation. Raising the cap demands a hard fork. Every holder would have to accept it. That’s a political wall that has never been scaled.
Core: The Structural Security Gap
Let’s go deeper than the narratives. The security question is real. I’ve spent the last four years auditing zero-knowledge proof systems and incentive designs for layer-2 protocols. In my work on recursive proof aggregation for a ZK-rollup, I saw how a fixed reward structure for validators prevented reorg attacks. When validators are paid per state transition regardless of fee volume, the incentive to reorg for a high-fee batch disappears. The same principle applies to Bitcoin’s base layer.
Currently, miner revenue from fees is negligible. During the 2021 bull run, fees peaked at around 30% of total miner revenue for a few days. But in the current bear market, fees contribute less than 2% on most days. The rest comes from the subsidy. After 2140, that subsidy disappears. If fee revenue remains low, the network’s hash rate will drop as miners exit. A lower hash rate makes the chain cheaper to attack. The cost to reorg the last 100 blocks drops from billions to millions.
Todd’s model is mathematically sound. If coins are lost at a rate of 1-2% per year (conservative estimates based on lost keys, forgotten wallets, and burned coins), and tail emission is set at 0.5% of current supply, the net supply actually decreases over time. The inflation rate is negative. The term “permanent inflation” is a misnomer. Smart contracts execute. They don’t negotiate. The code doesn’t care about marketing.
But the real issue is not the math—it’s the mechanism for changing the consensus rules. A hard fork to introduce tail emission requires every node, every exchange, every holder to upgrade. The 2017 SegWit2x debacle showed that even a planned hard fork with broad support can fail. The 2026 BIP-110 failure showed that soft forks with low miner support are dead on arrival. The community governance of Bitcoin has proven itself capable of resisting changes that lack supermajority consensus.
Critics argue that fees will grow as adoption increases. Lightning Network and other layer-2 solutions can scale transaction volume, but they also compress fee demand on the base layer. If most transactions settle off-chain, the base layer sees only channel open and close transactions. Those are few and low-value. In a world with millions of Lightning channels, the daily fee revenue on layer 1 might be a few hundred dollars. That’s not enough to pay for security.
Some propose increasing block size to accommodate more fee-paying transactions. But that opens a different can of worms: larger blocks increase centralization pressure on miners and node operators. The Bitcoin Core developers have consistently rejected this path.
Another angle: proof-of-work itself might be replaced by proof-of-stake. But that’s a different debate, and one that Bitcoin’s culture has historically rejected. The goal is to stay as close to the original design as possible.
Contrarian: The Trap Is Real—But So Is the Problem
Adam Back is right to be suspicious of narrative-driven hard forks. The BIP-110 episode was a textbook case of a small group trying to use a real problem (spam data in blocks) to push a solution that also served their interests. The tail emission proposal could be the same. If a small group of miners or developers wants to extract more value from the protocol, they could frame it as a security fix.
But the contrarian position is that dismissing the problem as a trap doesn’t solve it. The security gap is real. It will become more acute with each halving. Ignoring it doesn’t make it go away. The Bitcoin community has a tendency to kick the can down the road. “Fees will grow” is a leap of faith, not a technical guarantee. Liquidity is an illusion until it’s tested. Fee revenue is the same.
There is a middle ground. Instead of a hard fork that changes the 21 million cap, Bitcoin could implement a tail emission via a soft fork if the new issuance is hidden inside a commitment scheme. That’s technically possible but politically toxic. It would be seen as a stealth inflation. The community would reject it.
Another option: let the chain die. If fees are insufficient, the hash rate drops, and Bitcoin becomes a settlement layer only for large transactions. Small transactions move to sidechains. That’s a natural outcome of the current design. The question is whether the community is willing to accept that future.
Takeaway
The 21 million cap will not be broken in our lifetimes. The political cost is too high, and the community governance has proven resilient. But the debate will resurface with each halving, because the structural problem doesn’t go away. The question isn’t whether tail emission is technically sound—it’s whether the cost of losing immutability is worth the security gain. Smart contracts execute. They don’t negotiate. Bitcoin’s code is law. Changing it requires consensus that doesn’t exist. The security gap will remain, a ticking clock buried in the protocol. The market will price it in eventually.