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 Decay Curves: Why Your Glory Must Fade
The mathematics of why yesterday’s hero shouldn’t govern tomorrow’s world
The Dictator Problem (And Rome’s Brilliant Solution)
Here’s a fun party fact: the Roman Republic invented a job called “Dictator.” No, seriously. When barbarians were at the gates or Gauls were sacking the city, Romans could appoint one guy with absolute power. Full control of the armies. Authority over every citizen. Life and death in his hands.
The catch? Six months. That’s it. After 180 days, the Dictator had to hand back the keys, go home, and become a regular citizen again. If he didn’t? Well, that’s called “tyranny,” and Romans had strong feelings about tyrants (see: Brutus, knives, etc.).
This wasn’t an accident. The Romans understood something profound: contribution deserves recognition, but permanent power corrupts. Cincinnatus saved Rome, then went back to farming. Twice. That’s the model.
Now here’s the puzzle: how do you build this insight into the architecture of a civilization? How do you ensure that today’s breakthrough scientist doesn’t become tomorrow’s knowledge oligarch? That yesterday’s heroic founder doesn’t calcify into an obstacle for future innovators?
The answer is mathematics. Specifically: decay curves.
Stack Overflow: A Cautionary Tale of Permanent Reputation
Let me tell you about the zombie aristocracy of Stack Overflow.
Stack Overflow—the programmer’s Q&A site—has a reputation system. Answer questions, get upvotes, earn points. Simple enough. But here’s the design flaw: reputation never decays. Once you earn those points, they’re yours forever. Sounds fair, right?
Wrong. Dead wrong.
As of 2024, Stack Overflow has over 29 million registered users. But only about 1,159 people have crossed the 100,000 reputation threshold. The top 0.46% of users hold disproportionate influence over a platform that millions rely on daily.
Worse: many of these high-reputation users effectively retired from active contribution years ago. They answered questions about Java 6 (released 2006) or Oracle 8 (1997), accumulated points, and now sit on permanent thrones while the site struggles with relevance. Questions asked in February 2025 dropped to under 30,000—down 77% since November 2022.
Why? Partly because AI tools like ChatGPT give faster answers without judgment. But also because Stack Overflow became a gerontocracy of reputation. New contributors face a 68% non-participation rate—they don’t even bother engaging. Why compete in a game where the scoreboard was locked before you were born?
This is what happens when influence doesn’t decay. Early contributors accumulate advantages that compound forever. Newcomers can’t catch up, so they leave. The platform stagnates. The experts who remain are experts in yesterday’s technology.
Sound familiar? It should. It’s the same pattern that produces aristocracies, monopolies, and entrenched elites in every human system. The Romans saw it coming 2,000 years ago.
The Three Pathologies of Permanent Power
Without decay, every reputation system develops the same three diseases:
1. Incumbent Lock-In
The early birds don’t just get the worm—they get all the worms, forever. In Stack Overflow, users who joined in 2008-2009 answered simple, foundational questions that now have millions of views. A question like “How do I iterate through an array in JavaScript?” asked in 2009 still generates reputation points in 2025—even though anyone asking that today would be crucified for not Googling first.
The rules changed, but the scoreboard didn’t. Yesterday’s obvious contribution becomes today’s permanent dividend.
2. Relevance Drift
Here’s a brutal truth: knowledge has a half-life.
Scientists who study citation patterns found something fascinating: academic papers decay in relevance at a predictable rate. Across all fields, the “cited half-life”—the time it takes for citation rates to drop by half—averages 6.5 years. Health sciences decay faster (25-36 months) because medicine moves fast. Physics and mathematics decay slower (49-60 months) because fundamental truths persist longer.
But here’s the key insight: even Nobel Prize-winning papers eventually fade. More than 70% of citations are to papers published within the last 10 years. Papers older than 20 years are cited rarely.
A groundbreaking 2010 paper on social media algorithms is nearly worthless for understanding TikTok in 2025. The contribution was real. The expertise was genuine. But relevance decays whether you like it or not.
Any system that ignores this reality becomes a museum—curated by people whose knowledge expired before the current generation was born.
3. Effort Stagnation
When past achievements guarantee future influence, why keep trying?
Wikipedia learned this the hard way. As the site matured, it developed a class of “lone wolf” editors with accumulated influence. These veterans could revert newcomer edits, dominate talk-page debates, and shape content through sheer bureaucratic mass. New editor retention plummeted. Why contribute when some account from 2006 will just undo your work?
The Romans understood: reputation is not contribution. Cincinnatus wasn’t famous because he’d been a hero. He was famous because he kept going back to his farm. The title expired. The service didn’t.
How Impact Decays: The Mathematics
In the Unscarcity framework, Impact—the currency of contribution to humanity’s frontier missions—must decay. Not as punishment, but as acknowledgment that relevance is temporal and contextual.
The decay follows an exponential curve:
Impact(t) = Impact₀ × e^(-λt)
Or, more intuitively:
Impact(t) = Impact₀ × (1/2)^(t/half-life)
The book specifies a 3.41% annual decay rate, which translates to approximately a 20-year half-life. That means:
| Year | Impact Remaining |
|---|---|
| 0 | 100% |
| 10 | ~71% |
| 20 | ~50% |
| 40 | ~25% |
| 60 | ~12.5% |
Why 20 years? It’s a Goldilocks number—long enough to recognize lasting contribution, short enough to prevent dynasties. A scientist who makes a fusion breakthrough at 35 still has meaningful influence at 55, reduced-but-present influence at 75, and graceful acknowledgment by 95.
But—and this is crucial—they don’t control fusion research at 95. New voices get seats at the table. The field evolves. Power transfers to those doing the work now.
The Founder’s Discount: 5% Decay
One exception: Founder Credits earned through the EXIT Protocol decay at 5% annually instead of 3.41%. This is the “soft landing” for 20th-century power holders transitioning to the new system.
Why slower? Because you’re asking billionaires to trade real assets for imaginary points. If those points evaporated too fast, nobody would take the deal. The slower decay gives legacy elites a multi-generational adjustment period—their grandchildren will still feel the benefit—while still ensuring eventual power diffusion.
It’s not fair. It’s strategic. And it’s better than the alternative: civil war between those who have and those who will.
Different Contributions, Different Half-Lives
Not all contributions age the same way. The article that changes medicine probably becomes obsolete faster than the sculpture that moves souls.
Here’s a proposed framework:
| Contribution Type | Half-Life | Rationale |
|---|---|---|
| Crisis Response | 6 months | Heroism in the moment; rapidly obsolete |
| Governance Service | 1-2 years | Should reflect current engagement |
| Technical Infrastructure | 2-3 years | Systems require ongoing maintenance |
| Educational Contribution | 3-5 years | Knowledge evolves; methods improve |
| Community Building | 2-4 years | Relationships require maintenance |
| Scientific Discovery | 5-7 years | Matches academic citation patterns |
| Artistic Creation | 10-15 years | Cultural impact persists longer |
| Foundational Theory | 15-20 years | Like mathematics fundamentals |
These aren’t arbitrary. They’re derived from observable decay patterns in existing systems. Academic citations, Reddit’s content ranking, social capital research—they all point to similar timescales.
The person who coordinated evacuation during a hurricane deserves recognition. But that recognition shouldn’t make them the permanent Secretary of Emergency Management forty years later. Crisis heroism ages out fast.
The person who proved a new theorem in mathematics deserves recognition that persists longer—because the theorem itself persists. Pythagoras is still right.
The Impact Trust: Cheating Death (Sort Of)
“Wait,” you’re asking. “If my Impact decays 3.41% every year, how do I ever save up for something huge? A seat on the Mars expedition? Life-extension treatment? Anything requiring decades of accumulated contribution?”
Good question. The answer is the Impact Trust.
You can “commit” your Impact to a specific, validated life mission. When you do this, your Impact stops decaying—but it also becomes locked. You can’t use it for anything else. It sits in escrow until you reach your goal.
Consider Elara, from Chapter 2:
She’s spent forty years caring for dementia patients—some of society’s most invisible, undervalued work. In the old economy, this made her poor. In the Unscarcity framework, she’s been earning Impact the whole time. Not accumulating wealth—accumulating recognition of genuine contribution.
At 75, Elara applies for life extension. She wants twenty more years to train a new generation of caregivers. The treatment is genuinely scarce; we can’t yet offer it to everyone.
Her locked Impact Trust demonstrates decades of sustained dedication. Her contributions aren’t ancient history—they’re ongoing. The community reviews her application. Because her life has been spent serving others, the system serves her.
The Trust mechanism creates a hybrid: decay as the default, but ongoing commitment maintains influence. You’re not hoarding status; you’re saving for a breakthrough.
The “Refresh” Mechanic: Why Ongoing Relevance Matters
Pure decay has a weakness: it treats all past work identically. But some contributions keep contributing. Einstein’s 1905 papers are still cited. Shakespeare is still performed. The Linux kernel from 1991 still runs the internet.
The solution: Impact Refresh.
Three mechanisms slow decay for work that remains relevant:
-
Citation Refresh: If others build on your work, your Impact decays more slowly. Your 2030 paper on quantum computing is still being cited in 2040? You get credit for ongoing relevance.
-
Maintenance Refresh: Continued engagement in your contribution domain slows decay. The programmer who still patches their open-source library shouldn’t lose Impact as fast as the one who abandoned it.
-
Application Refresh: Real-world implementation of theoretical work renews Impact. Your fusion plasma theory from 2035 got deployed in an actual reactor in 2045? That’s a refresh event.
This creates the right incentives: make contributions that keep mattering, not just contributions that spike once and fade.
Reddit’s Brilliant Mistake: Decay Content, Not Users
Reddit solved half the problem.
The platform’s “Hot” algorithm aggressively decays post visibility. A viral post must keep gaining votes just to maintain ranking:
Hot Score = log₁₀(|upvotes - downvotes|) + (sign × age_in_seconds / 45000)
This creates a 10× decay every 12.5 hours. In 2025, posts that gain 20+ upvotes in the first hour dramatically outperform posts that slowly accumulate 100 upvotes over 24 hours. Time punishes old content regardless of total votes.
Result: constant content turnover. Fresh voices get front-page access. Yesterday’s viral post is today’s forgotten thread.
But Reddit made a critical error: user karma doesn’t decay at all.
A user who farmed karma in 2015 still has it in 2025. They can influence moderation, access exclusive features, and—since Reddit’s 2024 IPO—even convert karma into stock purchase opportunities. Users with 25,000-200,000 karma were invited to buy shares before the public.
Reddit understood that content should decay. They failed to understand that influence should too.
Gaming the Decay: Attack Vectors and Defenses
Any system gets gamed. Decay introduces new attack surfaces:
Attack 1: Sybil Swarms
Create multiple identities, earn Impact across many accounts, aggregate influence.
Defense: Proof-of-Personhood ties accounts to verified individuals. Social graph analysis detects fake-account clusters. Meaningful contributions require time investment, making mass farming expensive.
Attack 2: Timing Games
Stockpile contributions, dump them before major decisions, maximize influence at critical moments.
Defense: Rolling windows. Influence calculations use 30-90 day averages, not point-in-time snapshots. You can’t game timing if the system averages timing out.
Attack 3: Fake Refresh
Generate fake “citations” to slow decay on existing Impact.
Defense: Refresh events must come from independent accounts with no prior connection. Quality thresholds filter low-value citations. Diminishing returns—each refresh helps less than the last.
Attack 4: Low-Quality Maintenance
Pad contributions with garbage work to maintain “active” status.
Defense: Peer review gates new Impact issuance. Diversity Guard validation requires multiple independent perspectives. Low-quality work decays faster.
The Meta-Defense: Transparency
All Impact calculations, decay rates, and gaming detection should be publicly auditable. Bad actors can’t game a system they don’t understand—but neither can good actors trust such a system.
This is Axiom II: Truth Must Be Seen. The ledger is public. The algorithms are published. Community detection of novel attacks becomes possible. Independent verification enables trust.
Why This Matters: The Alexander Problem
Let me tell you about Alexander the Great’s empire.
Alexander conquered everything from Greece to India. When he died at 32, his generals asked: “Who inherits?”
His answer, allegedly: “The strongest.”
Result? Four decades of war as his generals carved up the empire. Millions died. Civilizations collapsed. All because Alexander’s power didn’t have an expiration date—it just… transferred.
Now imagine the opposite: Alexander’s conquests, by design, faded. Not the infrastructure he built—that persists. Not the trade routes he opened—those continue. But his authority over those systems decayed. His generals would have had to earn their own legitimacy, not inherit his.
This is the promise of designed impermanence. Impact decay isn’t about devaluing contribution—it’s about preventing contribution from calcifying into control.
The scientist who discovered penicillin deserves recognition. But she shouldn’t govern antibiotic policy eighty years later based solely on that discovery. Medicine moved on. New minds must lead.
The founder who built the world’s best logistics network deserves acknowledgment. But his grandchildren shouldn’t automatically control global shipping. They weren’t there. They didn’t build it. And the network itself has changed.
The Decay Curve as Constitutional Amendment
Here’s the philosophical move: make decay constitutional.
In the Unscarcity framework, Axiom IV: Power Must Decay isn’t optional. It’s not a policy preference. It’s architectural. Built into the mathematics of the system itself.
This is how you prevent the Star Wars trajectory—where abundance technology gets captured by a permanent elite who use it to enforce artificial scarcity forever. By encoding decay into the foundation, you make permanent oligarchy structurally impossible.
Not because permanent oligarchs are bad people (some are, some aren’t). But because permanent oligarchy is bad design. Systems without turnover become brittle. Knowledge without refresh becomes dogma. Power without expiration becomes tyranny.
The Romans knew this. They limited dictators to six months.
The Incas knew this. They used cacao beans—a currency that literally rotted—to prevent wealth hoarding.
We know this. We just forgot.
Impact decay curves are the modern implementation of an ancient truth: the future deserves fresh voices at the table.
Conclusion: Designed for Tomorrow
Impact decay isn’t punishment for past contributors. It’s acknowledgment that:
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Contributions matter, but current contributions matter more. The person solving today’s problem should have more influence than the person who solved yesterday’s.
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Different contributions warrant different decay rates. Crisis response ages out faster than foundational mathematics. Both are valuable; neither is eternal.
-
Ongoing engagement should slow, but not stop, decay. The Trust mechanism and Refresh rules reward sustained relevance, not one-time heroics.
-
The system must resist gaming while remaining transparent. All calculations public. All attacks detectable. Trust through visibility.
The goal is a civilization where yesterday’s heroes are honored—but tomorrow’s heroes aren’t blocked from emerging. Where contribution is recognized—but recognition doesn’t become dominion. Where the game keeps mattering—because the scoreboard keeps resetting.
Cincinnatus saved Rome, then went back to his farm. Twice.
That’s the model. The decay curve is the implementation.
Power must fade. Not because it never mattered—but because what matters now is what’s happening next.
Further Reading
- Impact — The full system design for contribution recognition
- EXIT Protocol — How legacy elites transition into the new system
- Guiding Axioms — The constitutional framework including Axiom IV
- Diversity Guard — How diverse validators prevent gaming
Sources
- Stack Overflow Statistics 2025
- Stack Overflow December 2024 Stats (GitHub Analysis)
- 2025 Stack Overflow Developer Survey
- Reddit Karma in 2025: How It Works
- Reddit Algorithm Mechanics
- Reddit Karma Business Integration 2024-2025
- Academic Citation Half-Life Research
- Bourdieu, P. (1986). “The Forms of Capital”
- Coleman, J.S. (1988). “Social Capital in the Creation of Human Capital”
- Parolo, P.D.B., et al. (2015). “Attention decay in science.” Journal of Informetrics
