How to run a real market economy inside a hard physical limit, and why almost every conventional instinct about how it must work is wrong.
J.W. Sher
June 6, 2026
There is one Earth, and we are not getting another. Whatever we do here we have to be able to keep doing for hundreds of thousands of years, because the alternative to a civilization that can last is a civilization that ends. The same problem shows up in miniature wherever humans live sealed inside a fixed envelope of resources: a nuclear submarine, the International Space Station, a future colony on Mars, a generation ship in deep space. In all of those places running out of air or water or fuel is not a market correction, it is a funeral, and so all of them are run as centrally planned economies in which an administrator decides in advance who consumes what. Earth has simply been large enough, for long enough, that we could pretend it was a different kind of place.
It is not a different kind of place, only a slower one. So the question I have spent years on is the one those sealed environments force but never answer: can you have a real market economy, with entrepreneurs and prices and competition and people getting rich, inside a hard physical limit you are forbidden to exceed? The two familiar answers both fail. Unconstrained capitalism is brilliant at producing cheap fish and perfectly content to produce the last fish, because its prices carry no information about the ocean having a bottom. Central planning respects the limit but cannot process the information of a real economy, and worse, once human welfare stops being the planner’s measure of success, a planner can hit its targets by destroying people as readily as by feeding them.
Free Market Ecology is my answer, and it is the most misunderstood thing I write about. Every reader arrives carrying a set of reflexes: a tax, a permit, a ration, a subsidy, a cap-and-trade scheme, a world government, a degrowth austerity program. At each step the framework gets quietly swapped for the nearest familiar item on that list, every one of which is wrong. The drift is so reliable that the cleanest way to explain the system is to build it one piece at a time and, at each piece, name the conventional reflex and say why it breaks. What follows is the framework from first principles, error by error.
The limit is physical, and it is the one thing the market does not get to vote on
Start with the only number that comes from outside the market. For every resource that can be drawn down faster than it returns, whether that is crude oil, aquifer water, fertile soil, fish stocks, the atmosphere’s capacity to absorb carbon, or ecologically load-bearing land, there is a maximum rate of use that can continue indefinitely without degrading the system that supplies it. That rate is a question for sustainability science, not for politics or willingness to pay, and it sets a hard ceiling on the physical quantity available in each period.
The reflex here is to picture a committee haggling that number up and down according to how badly everyone wants to consume. That is exactly what must not happen, because the entire point is to sever the quantity from demand. The cap is set conservatively and then tuned, and in practice the tuning runs only one way: revising a cap upward when the science turns out to have been too cautious breaks no one’s plans, while revising it downward breaks contracts, so you set it tight and treat the slack as the margin you loosen later. Inexhaustible inputs, such as sunlight and anything recycled out of the old economy, sit outside the cap entirely, which is the system quietly paying you to reuse what already exists.
This is the one genuinely planned element, and it is worth being honest that it is planned. But notice how little it decides. It fixes how much of each thing may be used. It says nothing about who uses it, or for what, or at what price, and everything interesting in an economy lives in those questions, which the cap deliberately leaves alone.
The state sets the limit, but it does not hand out the rights
Here is the first place the framework gets betrayed, including, years ago, by me. The obvious next move, once a central authority has fixed the ceiling, is to let that same authority parcel the quantity out: give each producer an annual allocation, issue each citizen a daily ration, run the whole thing off a central balance sheet. An earlier sketch of this system did exactly that, and it was the conventional reflex wearing the costume of a new idea. A government that allocates the rights is just central planning that has agreed to stop at the quantity. It still decides who gets oil, and it fails for the same informational reasons every command economy fails.
So the rights are not allocated. They are borrowed. A producer who wants to use a slice of the capped resource acquires the right to it on credit, from competing lenders I call Ecological Private Finance, and that right then clears on an open market. The central bank, which is really a federation of them, as later sections will show, mints no favors and picks no winners; it governs only the total, the way a monetary central bank governs a money supply without choosing who receives the loans. Who ends up holding the right to the last marginal barrel is settled by price and credit and the ordinary scramble of a market, not by an office.
If you find yourself describing a bureau that issues permits or rations consumption, you have left the framework and rejoined the planners. The cap is the only thing decided centrally. Allocation is always a market.
The unit is a physical right, not a price, and there is a different one for every kind of harm
This is the principle everything else hangs on, and the one the conventional mind dissolves fastest. The instinct is to hear all of this and conclude that it reduces to a price: put a number on environmental damage, charge it, and let the market sort out the rest. That is a carbon tax, and it is not what this is.
The accounting unit is not money. It is a physical Resource Usage Right, and there is a separate, non-fungible kind for each dimension of ecological cost: one for carbon, another for fresh water, another for a given class of land, another for a fishery. They are non-fungible in three directions at once, and each direction matters. They do not substitute: you cannot buy down the water cost of a product with cheap labor, or a subsidy, or a clever financial structure, because the right is denominated in water and only water settles it. They do not offset across dimensions: a water right cannot pay a carbon debt, because draining an aquifer and warming the air are not two sizes of the same thing, and any single number that lets one cancel the other is asserting a falsehood about the physical world. And they do not discount across time: a dead acre is dead whatever the interest rate, so the liability for long-horizon damage is carried at its full physical weight rather than shrunk to a present value the way money shrinks everything distant to almost nothing.
Money still exists, and it does most of what it does today: it prices labor, skill, ideas, intellectual property, reputation, everything humans value and trade that is not a draw on a capped physical resource. Money can even buy and sell the rights themselves. What it cannot do is the one thing that matters: settle an ecological debt. The obligation to cover the physical resource you actually used is discharged only by surrendering the matching physical right, never by paying cash in its place, because the moment a dollar could pay down a water debt, money would be buying down a resource cost and the substitution would be back. So money may buy you a water right, but only because some holder relinquished it for the money, and the cap fixes how many rights exist at all. The rights enter circulation through two channels, the universal income every citizen draws as a co-owner of the commons and what the government spends, and recirculate as the resource profit a producer earns. From there dollars only move them around; they never manufacture a right, shrink the rights embedded in a product, or stand in for surrendering a real one. So when someone says “a rising oil price pushes everyone toward solar,” they mean something exact: the price of the non-fungible oil right is climbing relative to the separate, non-fungible rights the solar pathway draws on, and producers are swapping one physical right for another. There is no master money price of “the environment.” There is a plural ledger of physically distinct scarcities, each debt settled in its own physical unit, and keeping them distinct is the whole achievement.
Damage is a liability you can only pay off in repair
What about the damage that does get done, the poisoned ground, the tailing pond, the stretch of seabed scraped bare? The familiar answer is the polluter-pays principle: charge the responsible party a fee, ideally a recurring one, and call the books balanced. But a fee paid in money for damage left standing in the world is the single-price error again, dressed up as justice; it lets cash stand in for a repair that never happens.
A liability in this framework exists only where physical damage exists, so where there is no damage there is no liability and nothing owed, and it is discharged only by physically undoing the damage, restoring the degraded land or letting the depleted system recover. You cannot settle it with a check, because the check un-poisons nothing. Nor does the liability sit forever on the producer who caused it as a perpetual fine; it is deposited downstream onto the account of the end beneficiary, the consumer who actually wanted the thing the damage produced, and in practice onto that consumer’s jurisdiction, which is what turns trade policy into the lever that manages it. One instinct from the first version of this idea was right about a single thing: if you take possession of something and throw it away unrecovered, the resource stays on your books. Generalize that and you have the principle: destruction is an outstanding debt against the physical world, payable in one currency only, which is restoration.
The framework is a machine, not a manifesto
It is tempting, and I have done this too, to load the system with values: to declare that nature comes first, that virgin land is sacred, that all human ends are subservient to the planet. That is a moral stance, and people are free to hold it, but it is not part of the machinery, and welding it on as though it were is a category error.
Free Market Ecology is a mechanism: it sorts ecological costs into non-fungible physical units, caps each at a sustainable quantity, and lets credit and markets allocate the rest. It does not dictate which buckets exist, where their boundaries fall, or which of them a society chooses to guard most jealously. Whether a particular forest is treated as untouchable or as ordinary working land is a political and jurisdictional decision made on top of the machine, not a law of the machine. This matters because a mechanism can be adopted by people who disagree profoundly about ends. A deep ecologist and a frontier industrialist can run the very same system and fight their fight inside it, through where each sets caps and draws classes, instead of having to first win a war over first principles. Keep the machine and the morality apart. The machine is the part that is new; the morality is the ordinary business of politics, and the framework is deliberately silent on it.
It runs on greed, and conservation is the profitable move
The deepest misreading is that all of this must hurt, that a system organized around physical limits has to be a program of austerity and sacrifice and being scolded into using less. It is the opposite, and that reversal is the core of the whole design.
Because the quantity is fixed, the only way to produce more value is to produce more value per unit of resource. A producer acquires the rights it needs by borrowing them on credit from competing Ecological Private Finance lenders against posted collateral. An efficient producer’s process requires far fewer actual Resource Usage Rights than a dirty competitor’s — near-zero damage instead of significant damage. When the product is sold, however, it carries an embedded RUR cost set by what buyers will pay in the market — the quantity that reflects the rights a dirtier producer would have to borrow and pass downstream. The efficient producer receives payment in RURs at that full market price but only has to repay EPF the smaller quantity it actually borrowed (plus carrying cost). The difference is the producer’s resource markup: genuine profit, denominated in RURs, earned by creating more value from less of the Earth.
The resource owner, holding a right to something that cannot be manufactured more of, gets rich by conserving it and selling its use dear rather than by dumping it cheap. Efficiency becomes the most profitable position in the market, which means the ordinary engines of capitalism, its competition and ambition and even its greed, are aimed straight at the environmental problem instead of against it.
This is also what kills the Jevons Paradox, the nineteenth-century observation that making a resource more efficient to use tends to make people use more of it, not less. That rebound runs on the quantity being free to expand. Here it cannot expand; the cap holds. So efficiency does not summon extra consumption; it frees the saved resource to satisfy some other want while the total draw on the Earth stays inside the line. Marx asked the right question, who captures the surplus a society produces, and answered it catastrophically. This is a different answer: the surplus goes to whoever creates the most value from the least nature, and that is a contest worth winning.
The citizens own the commons, and that is ownership, not redistribution
There is one more reflex to clear, the one that hears all this and calls it a scheme to take from the rich and hand to the masses. It is nothing of the kind, because there is no one to expropriate. The commons, meaning the atmosphere, the aquifers, the fisheries, and the capped resources every producer must draw on, belongs to the citizens to begin with; it is not seized and redistributed after the fact. Producers still develop it, mark it up, and grow wealthy. What changes is only that the resource they draw on has owners, and those owners are everyone.
This becomes the decisive question as automation advances. For two centuries ordinary people have held a claim on the economy through their labor: they had something to sell. When machines can do the work for less than it costs to keep a human worker fed, that claim evaporates, and a population with nothing to sell is a population with no stake in the economy that has replaced it. That is the precondition for every ugly future, from mass dispossession to the factions warring over who controls the robots.
Free Market Ecology hands that population a different and durable claim: ownership of the physical commons that all production, automated or not, must still buy its way into. A machine-run process owes no wages, so its goods are nearly free in money terms, but it still has to acquire the non-fungible rights to the resources it consumes, and those rights are owned by the citizens. The income every citizen draws is paid in exactly those rights and in nothing else. It is a flow of RURs, not money: the commons paying out each owner’s share of the physical resources the economy has to use. There is no free money in it. Anything that still takes human labor must still be bought with money, and money is still earned by working, so if others have to work, you have to work too.
The one way to avoid working is to want almost nothing: a citizen who lives on a very tight resource budget leaves part of his allocation unspent, and those unused rights can be sold for money to people who want to consume more, so the very frugal can live on the proceeds of the share they decline to use. Even then the money is not free, because it is paid for by giving up the physical consumption the rights represent. What this universal resource income removes is not the need to work but the threat of being cut off from a share of the Earth itself, and that share is grounded not in charity or redistribution but in property, the one kind of standing a robot cannot underbid.
No one is in charge
The last reflex is to assume that running all of this demands a single authority, a global environmental government empowered to set the world’s caps and police them. That would be both impossible and dangerous: impossible because no such authority could ever be agreed to, dangerous because a single point of control over every physical resource on Earth would be an irresistible target for capture.
So there is no global government, and its absence is a feature. The system is a nested federation of jurisdictions, each setting and bearing the consequences of its own caps, the way many central banks coordinate without a world central bank above them. Discipline between jurisdictions that do not trust each other comes not from treaties but from self-interest and from a ledger. Every rule is enforced by the party whose own interest it serves: a jurisdiction that issues rights carelessly is left holding the unsettled liabilities, so it issues carefully; a country sitting on a depleting resource guards its cap the way a cartel guards supply, because the scarcity is its wealth; every citizen is a part-owner of the commons, so untracked extraction is theft from each of them. The provenance of every resource is tracked on a shared blockchain, not because the technology is fashionable but because two rivals who each suspect the other of cheating, over how much oil was really burned or whether it was made with hidden subsidies and coerced labor, can both rely on a ledger that has to close. The chain forces the books to balance between adversaries who agree on nothing else.
What this does not solve
A framework earns more trust from what it concedes than from what it claims, so the open edges belong in the foundational essay, not in a footnote somewhere.
The first is shared physical flows. A river that crosses three jurisdictions, an airshed over a dozen, the carbon sink over all of them: where the physical system itself spans borders, no single owner guards the cap out of self-interest, and the discipline of unilateral penalty rates plus the ledger is at its weakest, because the defector keeps the gain and exports the harm. The federation handles owned, located resources well; the genuinely common pools are the framework’s hardest case, and I do not claim they are solved.
The second is measurement below the wellhead. Extraction is the easy end: barrels, board-feet, and acre-feet are already metered as routine commerce. But the embedded resource content of finished goods has to be carried through supply chains with hundreds of inputs, and some dimensions — nitrogen runoff from a thousand farms, the condition of soil and habitat — have no meter at all. The ledger can force the books to close only where there is an honest number to enter at the start of the chain. The framework’s rollout has to follow the measurable dimensions first, and how far the measurable frontier can be pushed is an engineering question I cannot settle from the armchair.
The third is the falling cap. The tuning rule says set the cap tight and revise upward, because loosening breaks no contracts. But for a depleting stock, or a science that turns out to have been too generous, the physics can force a cap downward, and a downward revision lands on outstanding loans and priced-in expectations. Who eats that loss — borrowers, lenders, the issuing jurisdiction — is a design question the framework constrains but does not fully answer.
What the machine adds up to
Step back and the whole thing is a single device. Physics fixes how much of the Earth may be used. Markets and credit, not officials, decide who uses it and for what. The accounting is kept in plural physical rights that cannot be substituted, offset, or discounted away, so no clever price can launder a real harm. Damage is a debt against the world, payable only in repair and charged to whoever benefited. Conservation is the most profitable move on the board, so greed pushes toward sustainability instead of away from it. The citizens own the commons, which gives them a claim that outlives the usefulness of their labor. And no one is in charge, because the discipline lives in the incentives and the ledger rather than in a ruler.
That device maps, in the trivial case, onto exactly the careful allocation a submarine or a space station already performs by hand. But unlike the submarine it scales, because it does the allocating through markets instead of through an administrator who must somehow know everything. It is the economy you could run on Mars, on a ship in deep space, and on a near-future Earth that has finally noticed it is one of those sealed environments too, only larger and slower.
I called the first version of this an outline, and it leaned on the state to do the work because that was the reflex I had not yet shaken off. The framework’s actual content is everything that reflex gets wrong. Hold onto the corrections above and you have it; reach for the conventional neighbor at any step, whether the tax, the permit, the ration, the world government, or the program of sacrifice, and you have lost it. The detailed mechanics of each piece are what the companion essays are for.