Note: This is a research note supplementing the book Unscarcity, now available for purchase. These notes expand on concepts from the main text. Start here or get the book.

Impact vs Soulbound Tokens: A Technical Comparison

Why the book stopped saying “Impact is not crypto” and started owning the lineage

The Reasonable Confusion

If you read the Impact chapter carefully, you noticed something. Impact has a public ledger. Impact uses zero-knowledge proofs to verify contributions without exposing private data. Impact is recorded across millions of computers so no single party can tamper with the record. Impact is non-transferable and bound to a specific person.

If you have spent any time in the crypto literature, you read those four properties and said the obvious thing: that is a soulbound token. The book’s earlier line, “Impact is not crypto,” read as defensive. The architecture is, in fact, in the same family as some crypto architectures. Saying it is not crypto while describing crypto-shaped properties is the kind of move a reader stops trusting after the second time.

The honest answer is that Impact is in the soulbound-token lineage at the protocol layer, and is the economic opposite of every cryptocurrency you have heard of. Both can be true at the same time. This article shows where the lineage stops and where the divergence starts.

The Lineage: Buterin, Weyl, Ohlhaver, 2022

The closest formal cousin to Impact in the academic literature is a 2022 paper by Vitalik Buterin (the co-founder of Ethereum), Glen Weyl (the Radical Markets economist), and Puja Ohlhaver, titled Decentralized Society: Finding Web3’s Soul. The paper proposes what they call soulbound tokens (SBTs): tokens that are issued to a wallet (a “Soul”) and cannot be transferred out of it.

The motivation in the paper is the same motivation Impact starts from. Cryptocurrency, as it actually exists, optimizes for transferability and liquidity. Everything is a market with a price, and everything can be sold to the highest bidder. That economic shape produces speculation, wash trading, and the rapid concentration of wealth in whoever bought in earliest. It does not produce a usable substrate for reputation, credentialing, governance, or any of the things that distinguish a society from a casino.

The SBT proposal asks: what if you kept the cryptographic plumbing but built a token that cannot be sold? What you get, Buterin and his coauthors argue, is something closer to a reputation or credentialing system, a network of social commitments, than a financial instrument.

Impact takes that proposal seriously and pushes it further.

The Structural Comparison

Read the table from left to right and you can see two transitions. The first transition, from Bitcoin/Ethereum to SBTs, removes the speculative market and the financial-instrument framing. The second transition, from SBTs to Impact, removes everything else that lets accumulated influence become permanent.

What Crypto Gets Right (and Impact Borrows)

Three crypto contributions are load-bearing for Impact, and Impact would not work without them.

Tamper-evident public ledgers. The Bitcoin whitepaper’s central insight, that you can build a record everyone can read and no one can secretly alter, is the single most important infrastructural invention of the last twenty years for any system that needs trust without a trusted institution. Impact runs on a ledger of this kind. Every recognized contribution is appended; nothing is ever quietly deleted. A future government cannot scrub the record of a dissident’s contributions, because the record is replicated across enough independent operators that the discrepancy would surface on the next sync.

Zero-knowledge proofs. ZK-proofs, deployed in production by Zcash and increasingly by Ethereum’s privacy roll-ups, let a system verify “this person earned 500 Impact for eldercare, validated by four diverse councils” without exposing “this person spent every Tuesday afternoon from 2026 to 2031 with Mr. Rodriguez at 123 Maple Street, who has Lewy body dementia.” The accounting is public. The lived life is not. That separation is not a nice-to-have for a reputation system; it is the difference between a credentialing infrastructure and a surveillance regime.

Byzantine fault tolerance. The consensus literature that came out of cryptocurrency research, particularly the work on BFT validator sets, gave us protocols that keep working when up to a third of participants are actively malicious. Impact’s MOSAIC validator network borrows directly from this lineage. A captured council, a corrupted node, a coordinated attack on a fraction of the validators: the protocol tolerates them and surfaces the attempt in the audit trail.

If those three contributions had not existed, Impact would be a Soviet merit badge. They exist, so it is not.

What Crypto Gets Wrong (and Impact Inverts)

Four crypto design choices Impact rejects, each on purpose.

Transferability. Every major cryptocurrency is built around the assumption that a token must be sellable. The moment you allow that, you create a market price, and the moment you have a market price, the token becomes a financial instrument that whoever bought in earliest will own most of. The Pareto distribution of Bitcoin holdings, where roughly 2% of addresses hold 95% of supply, is not a bug in execution; it is the inevitable consequence of designing for liquidity. Impact is non-transferable not as a technical accident but as an economic axiom. There is no exchange where you can sell your eldercare credit to a yacht buyer in Monaco. There is no exit liquidity, ever.

Permanence. Bitcoin’s hardest design choice is its fixed supply. Ethereum’s supply changes only at the protocol layer, never at the holder layer. In both cases, what you accumulated in 2010 is still yours in 2030, regardless of whether you have contributed anything since. That permanence is good for a store of value and catastrophic for a measure of contribution. Impact decays at roughly 3.4% per year, halving every twenty years, because yesterday’s hero should not govern tomorrow’s world. The decay curve is the difference between karma and capital.

Economic-incentive consensus. Proof-of-work and proof-of-stake both work by paying validators to be honest. Mine a block, get coins. Stake your coins, earn yield. The economic logic is elegant and the energy footprint is, in the case of PoW, ruinous. Impact uses neither. Validators are MOSAIC councils selected for diversity and rotated on a schedule; the mandate is civic, not economic; the audit is public. Nobody earns Impact by validating Impact. That separation is what stops Impact from collapsing back into the rich-get-richer attractor that every economic-incentive consensus eventually finds.

Speculation as a first-class function. In the crypto economy, speculation is not a side effect; it is half the user base and most of the volume. Half the value of Ethereum is “people betting that other people will want Ethereum.” Impact has no analogue. There is nothing to bet on, nothing to short, nothing to leverage, nothing to wash-trade. A token whose only function is to record what you contributed cannot be traded against itself, because there is no second party to take the other side.

The Three Departures, Stated Plainly

If you want the soulbound-token comparison in three sentences:

1. Non-transferable by design, and the design is enforced at the protocol layer, not at the social layer. SBTs are non-transferable by convention, with proposals to allow “community recovery” of a Soul’s tokens. Impact is non-transferable as a hard rule, with no recovery and no exception. If your wallet is lost, your Impact decays normally and a new wallet starts at zero. The system is unforgiving on purpose.

2. Decaying over time, so accumulated influence cannot become permanent. This is the single largest departure from both crypto and SBTs. Almost all crypto tokens, and most SBT proposals, treat accumulation as monotonic; once you have it, you have it. Impact treats accumulation as a flow, not a stock. You must keep contributing or your influence quietly fades. The curve is calibrated so that twenty years of inactivity halves your standing; sixty years reduces it to one eighth. Decay is not meant as punishment. It exists to make the rules of attention match the rules of relevance.

3. Federated consensus across rotating MOSAIC validator councils, rather than economic incentives. Crypto pays its validators. Impact selects its validators by diversity, rotates them on a schedule, and pays them nothing. The mandate is civic. The audit is public. Capture is structurally harder because no validator stays on a council long enough to build the relationships that capture requires. The Diversity Guard is the safeguard against the failure mode the SBT paper specifically worries about: a small clique of Souls coordinating to issue and verify each other’s tokens until the credential is meaningless.

Stack those three on top of the soulbound-token starting point and you get Impact.

Why the Distinction Matters

The skeptical reader, fairly, asks: who cares about the taxonomy? If it looks like crypto and ledgers like crypto, the public will treat it like crypto, with all the attendant disgust and burnout. There are two answers to that.

First, the public’s disgust with crypto is overwhelmingly about its economic shape, not its cryptographic shape. People are angry about rug pulls, FTX, NFT bubbles, Tether’s audits, and the energy footprint of proof-of-work. They are not angry about Merkle trees. Impact removes the parts that are objectionable and keeps the parts that are useful. The right framing is not “Impact is crypto” or “Impact is not crypto” but “Impact is what you get when you take crypto’s cryptographic infrastructure and refuse its economic premises.”

Second, the distinction matters for what the system can become. A reputation infrastructure that inherits transferability inherits speculation, and a reputation infrastructure that allows speculation will eventually become a financial instrument and stop being a reputation infrastructure. The economic axioms determine what the system grows into ten years out. Non-transferability, decay, and civic consensus are the three load-bearing axioms. Drop any one of them and Impact converges, slowly, to something that looks like a securitized credit score traded by hedge funds. Hold all three and it stays what it was designed to be: a public record of recognized contribution, anchored in math, owned by no one, traded by no one, fading by design.

A Final Note on Honesty

The book’s earlier line, “Impact is not crypto,” was meant to head off the speculative-scam association the public has with the word. It read, fairly, as defensive. The architecture is in the soulbound-token family. Owning that lineage is more credible than disavowing it, and it lets the reader see exactly which design choices Impact inherits and which it inverts.

Impact uses the math that came out of cryptocurrency research but inverts every economic assumption. That is a longer sentence than “Impact is not crypto” and it has the advantage of being true.

Further Reading

• Impact: The Currency That Must Die - The main Impact article
• Impact Decay Curves - The mathematics of fade-by-design
• Diversity Guard - How rotating councils replace economic consensus
• Chapter 2: The Frontier - The full vision of the meaning economy
• Chapter 3: The MOSAIC of Commons - Where the federated consensus mechanism is built

References

• Buterin, V., Weyl, E. G., Ohlhaver, P. (2022). Decentralized Society: Finding Web3’s Soul. SSRN 4105763.
• Nakamoto, S. (2008). Bitcoin: A Peer-to-Peer Electronic Cash System.
• Ben-Sasson, E., et al. (2014). Zerocash: Decentralized Anonymous Payments from Bitcoin. (foundational Zcash paper)
• Castro, M., Liskov, B. (1999). Practical Byzantine Fault Tolerance. OSDI ‘99.
• Parolo, P. D. B., et al. (2015). Attention decay in science. Journal of Informetrics.