The argument of the volume
To see why the commons defeats the price, one must see what the price requires to work. A price is a toll at a gate: to charge it, one must be able to bar those who do not pay, so the good must be excludable. And a price rations a scarce thing among rival claimants, each of whose use denies the thing to another. Ordinary private goods have both properties: the apple I buy is mine, you are excluded, and my eating it leaves none for you. But the world holds goods that lack one property or the other. The fish in the open sea are rival — each netted fish is one fewer for the next boat — yet non-excludable, for no one can fence the ocean; this is the common-pool resource, the commons proper. The light of the lighthouse is non-rival — one ship's use of it dims it for no other — yet also non-excludable, for it shines on every passing hull; this is the public good. A fourth case completes the square: a good non-rival like the lighthouse, shared without using up, yet excludable like the apple — the swimming pool, the toll bridge, the members' library, which many may enjoy together but from which any may be barred. This is the club good, and of all the shared things it is the one where a gate can still be built and a price still charged; the volume takes it up early, as the boundary of the failure. But in the common-pool and the public alike, non-excludability defeats the toll: there is no gate at which to charge, and so the price, the market's whole engine, cannot turn.
From the failure of the gate flow the two great pathologies, which are one pathology in mirror. Where the shared thing is rival and unowned — the commons — it is overused, ruined by a stampede of takers: each herdsman who adds a beast to the common pasture gains the whole of that beast and bears only his share of the resulting overgrazing, so each adds, and the pasture is grazed to death, though all would be better had all restrained. Where the shared thing is a benefit none can be charged for — the public good — it is underprovided, starved by a strike of shirkers: each citizen who might fund the lighthouse benefits whether he pays or not, so each waits for another, and the light is never built, though all would gain were it. Overuse of the common cost, underprovision of the common benefit: the tragedy of the commons and the free-rider problem are the same divergence — between what serves the one and what serves the group — seen from its two sides. And beneath both lies a structure the theory of games would name: a trap in which each, reasoning soundly, chooses the course that ruins all.
That the price cannot govern the commons has long seemed to leave only two who can. The first is the state — the Leviathan that, standing above the users, commands what they may take and provides what they will not, by quota and by tax and by public works. The second is property — the fence that carves the commons into private parcels, so that each owner, now bearing the whole cost of his own overuse, restrains himself as the herdsman would not. Regulate or privatize; the state or the market; coercion from above or enclosure from within — between these two the argument over the commons ran for a century, and both, note, concede the central point of this family: that the price, left alone, fails, and must be either replaced by command or rebuilt by the manufacture of property. But there is a third possibility, which the quarrel of state and market obscured, and which the volume builds toward: that the users themselves, neither commanded nor divided, might govern what they share — and that the tragedy thought to make this impossible was an artifact of the very assumptions that declared it inevitable.
The argument remains open. What follows is an attempt to fix its exact edges.
The twelve plates of this volume
- i The Pasturein print Hardin's tragedy: how a pasture open to all is grazed to ruin, each herdsman gaining the whole of his beast and bearing only a sliver of the cost, till the field that feeds all feeds none. Read the plate →
- ii The Clubin print Buchanan's club goods, the fourth kind: the swimming pool, the toll road, the members' library — excludable yet shared, and the right size for a thing whose crowding all its holders feel. Read the plate →
- iii The Lighthousein print the public good and its free rider: how a light that shines for every ship, and can be withheld from none, is one the market will not build — the mirror of the commons, a shared benefit too little supplied. Read the plate →
- iv The Free Riderin print Olson and the logic of collective action: why the larger the group that shares a goal, the less any member will lift to reach it, and why the common interest so often goes undefended. Read the plate →
- v The Fisheryin print Gordon's model and the cure: how open water dissipates the wealth of the sea, and how the two orthodox remedies — the state's quota and the private quota-holder — each try, by command or by ownership, to undo it. Read the plate →
- vi The Enclosurein print the privatizing cure and its violence: how the fencing of the common field can end the tragedy and end a way of life at once, the right to the land bought at the price of the right to its use. Read the plate →
- vii The Leviathanin print the state as keeper of the commons: regulation, the public trust, and the provision of what markets will not — and the distant guardian's twin failings, ignorance of the local and capture by the strong. Read the plate →
- viii The Covenantin print the third way: Ostrom's discovery that communities can govern a commons themselves, by rules of their own making — neither the state nor the fence, but the binding faith of those who share it. Read the plate →
- ix The Knowledgein print the purest public good: an idea that all may hold at once and none use up, the science and the song and the open code — and the puzzle of paying to make what costs nothing to share. Read the plate →
- x The Trustin print the social capital beneath the rules: the reciprocity, reputation, and trust that let neighbors keep faith where no contract binds, and the slow making and quick breaking of it. Read the plate →
- xi The Sanctionin print how a self-ruled commons enforces itself: the watchful neighbor, the graduated penalty, the punisher who pays to punish — and the repeated game in which cooperation can, at last, be made to hold. Read the plate →
- xii The Planetin print the commons with no sovereign: the climate, the oceans, the web of life, shared by every nation and ruled by none, and the question whether a globe can be governed as a village is. Read the plate →
In closing
This volume closed the third family by taking up the price's last and deepest failure. The asymmetry showed the price unable to convey what one side hides; the externality, unable to count what no one owns; the commons shows it unable even to engage a whole class of goods — the shared and the collective, rival but unownable, or beneficial but unchargeable — for the price is a toll, and where no gate can be built, no toll can be charged.
The failure, the volume showed, has two faces. The common pasture, rival and unowned, is overgrazed, each herdsman taking the whole of his beast and bearing but a sliver of the ruin, until the field that fed all feeds none; the public lighthouse, beneficial and unchargeable, goes unbuilt, each who might fund it waiting for another, until the common interest, which all share, none defends. Overuse and underprovision, the tragedy and the free rider, are one divergence in mirror — and beneath them, the logic of collective action: that the larger the group that shares a good, the weaker each member's hand in securing it. Against this the age set two cures, and only two. The state might command the commons from above, by quota and public works; or property might carve it from within, the fence giving each user the whole cost of his own excess to bear. Regulate or privatize: between the Leviathan and the enclosure the argument ran, and both conceded that the users, left to themselves, were helpless.
And then the volume turned on the parable itself, and found the helplessness to be the parable's assumption rather than the commons' fate. Elinor Ostrom went and looked, at pastures and forests and fisheries and irrigation works governed in common for centuries, and found the tragedy averted not by the state and not by the fence but by the users themselves — bound by rules of their own making, watched by their own monitoring, held by their own graduated sanctions and their own slow-built trust. The tragedy, she showed, was the property of a particular helplessness — of users imagined as mute, anonymous, and unable to bind themselves — and where that helplessness is overcome, where the users can speak and watch and promise and punish, the meadow need not be overgrazed at all. So the shared meadow is overgrazed when those who share it cannot govern themselves, and not otherwise; and the question whether it must be is answered, against the parable, with a qualified and hard-won no. With this the failures stand complete: the price cannot convey what is hidden, cannot count what is unowned, and cannot defend what is shared — three limits of the great coordinator, three regions of economic life where the price must be conveyed, corrected, or governed by something other than itself. And that something — the signal devised, the right assigned, the covenant kept — is the subject of all the table has yet to treat: the institutions that scaffold the market, and the behaviors that underlie the covenant. The price was never the whole of economic life. The failures are the family that marks its edges; what lies beyond them is the rest of the science.
If the meadow is overgrazed only when those who share it cannot govern themselves, then the tragedy of the commons is not a fact of scarcity but a failure of community — and the question is no longer how to price the meadow, nor who shall command it, but whether those who share it can yet learn to keep faith. Can they?