Property Rights and Externalities

Apples on a tree in a public park get picked before they ripen. Public beaches end up littered. Garbage gets dumped in rivers, and the air over a big city fills with smog. People reach for an easy label when they see these things: the market has failed, commerce fouls the commons, and the government must step in.

I want to convince you the label points at the wrong culprit. None of those problems is a place where buying and selling broke down. They are places where it never got started, because nobody owns the thing being spoiled, so nobody can sell it, defend it, or charge for ruining it. The unripe apples, the trashed beach, the polluted river: each is a property-rights problem wearing a market-failure costume. Once you see it that way, a long list of controversies, from pollution to overfishing to the supposed squalor of public services, turns out to run on one engine. By the end of this post you should be able to define an externality, diagnose an alleged market failure as a missing property right, and compare bargaining, taxes, and tradable permits as remedies. This is also where a thread from the opening topic pays off: owning something means holding several powers at once, and now we build that idea out.

A Property Right Rests on Control and Specification, and Those Make It Salable

Start with what a private property right actually is, since everything else hangs on it. To own a resource is to hold an enforceable claim to control it, to enjoy what it yields, and to transfer it to someone else. That last power has a legal name: alienability, the lawyer’s word for salable. A right you cannot sell is a stunted thing, and alienability does not come for free. It rests on two pillars.

The first is control. A property right is only as real as your ability to govern the resource and the services it provides. Ask what it would mean to own the North Star, or a particular whale last seen somewhere in the North Pacific. You could hold a deed, but you could not govern the thing, so the “right” would be empty. Control is also why a concert pianist cannot simply own the music she makes. The moment she plays, the sound spills out to everyone in the room. What she can control is the room, so she rents seats and ties the music to the ticket: pay to be in the hall, and the playing comes “free.” People invest in control, with locks, fences, and title companies, when the resource is worth the bother, and the higher its value, the more it is worth spending to control it.

The second pillar is specification. Even a well-guarded resource cannot trade smoothly unless the rights to it are clearly defined and verifiable. A buyer needs to know exactly what is being sold, that the seller really holds it, and that no hidden claim by a creditor or co-owner will surface later. The clearer that specification, the more cheaply the right changes hands. Much of what we call the cost of a transaction is the work of pinning down who owns what, which is why deeds to land and titles to cars sit in public registries backed by title insurance.

Put the two together and you get an alienable right, and alienability lets a resource move toward whoever values it most. One caution belongs here. Owning a thing does not mean no one can affect it. Others affect the value of what you own all the time, simply by changing their minds about what they will pay, and you are not entitled to make them keep paying. Ownership is a bundle of enforceable powers over a thing, not a guarantee about its price.

Suppressing a Property Right Does Not Erase Its Value, It Changes the Rationing

Here is a question worth sitting with. If alienable rights push resources to their best use, why would anyone deliberately build an institution that throws those rights away? Your own college is a good case. You belong to the student body, but you cannot sell that membership when you graduate, the way an owner of Apple or Ford can sell a share. Most of the college’s resources are held in a way that strips out the powers of private property: an administrator controls them and may buy supplies and labor, but the law forbids letting anyone use those resources as salable, ownable things. Why give up so much? Partly the government rewards it with tax exemptions, but the deeper reason is that doing so deliberately points the people in charge away from chasing profit. Whether that is good is a separate question; the point for us is mechanical. When you forbid an authority from pocketing a price, you do not abolish the value of the scarce thing it controls. You force that value to be collected in some other coin.

You see the same thing when a college blocks two students from swapping a parking permit for a library desk. The administrators cannot sell the spots, since the spots are not theirs to sell, yet the power to decide who gets a scarce space is valuable all the same, and the college is giving away something of value it could have charged for. That value gets captured in favors, goodwill, and the discretion to reward whoever the administration prefers. Suppress the money price, and competition for the scarce thing moves into nonmonetary channels, where someone still collects the value.

Campsites in state and national parks are priced so low that, at busy times, far more people want space than the parks can hold. Why does the fee sit below the level that would match the crowd to the campsites? The sites are not privately owned, so no one can pocket a market-clearing price, the price stays low, and the gap shows up as a line of cars at dawn. Two golf courses sit side by side, one private and one public, both open to all. The private course charges more and needs less reservation, since its owner keeps the proceeds and prices to clear; he also watches land values, and when the land is worth more as houses than fairways, he is the one who can cash out, so the private course converts first. The public course, run by officials who cannot personally pocket the gain, lags on both counts. The same logic explains why a beachfront state campground has cars queued for hours each morning while the luxurious motel next door rarely fills its rooms. That is not Californians revealing a love of dusty tents over pools and room service. It is a public facility priced below clearing beside a private one that uses the law of demand to match its guests to its rooms.

Churches, being nonprofit, often hand out their best seats first-come-first-served rather than selling them, though a large donor is sometimes granted a favored pew. Your not-for-profit college almost certainly rations its library, athletic facilities, course seats, and admissions below what they would fetch, and the power to choose who gets in is itself a prize: administrators cannot bank a profit, but they can bank prestige, donations, and the goodwill of the right families. Athletic conferences and the Masters chronically have far more ticket-seekers than tickets, since the people running them gain community stature, not bigger paychecks, by pricing below clearing. Immigration quotas go out at a price of zero rather than sold to the highest acceptable bidder, because the salaried officials who allocate them collect no money from the sale and so pursue other goals. In every case the same thing holds: a valuable right priced below clearing produces chronic excess demand, and the value nobody may charge for gets paid out in queues, favors, and discretion.

This also dissolves a famous complaint. A well-known book once argued that we live amid private abundance and public squalor: shiny private cars rolling over shabby public streets, a “shortage” of public services proving we provide too few of them. Look at the hint buried in the word shortage. Government services are handed out at prices far below clearing, often free, so of course demand outruns supply and the parks feel starved. That appearance of shortage is what underpricing always produces. It is not evidence that too little is provided, any more than a dawn line of campers proves we need more campgrounds. It proves the price is set too low, exactly as in the commons.

It is worth pausing to see how far this engine reaches, because people sometimes assume economic reasoning is a feature of capitalism, a thing that only describes a society organized around private property and market prices. That is backwards. Economics is the study of how any society resolves the conflicts that scarcity forces, whatever its institutions, and the analysis we just ran is the proof. Setting a price below the clearing level and watching the scarce thing get rationed by queues, favors, and official discretion is precisely what happens under socialism, where free-market prices are suppressed on purpose. The Soviet system still used money and let households choose among consumer goods, but it fixed many prices below clearing, and the predictable result was lines and nonmonetary rationing of the same kind we have been tracing. The laws of demand and of scarcity do not switch off when the legal system changes. They hold in every society we know of; only the institutions through which they operate differ.

An Externality Is an Effect on Others for Which No Agreeable Compensation Is Made

We are allowed to act in ways that spill over onto other people, and economists call those spillovers externalities: effects on others for whom no mutually agreeable compensation is made. The compensation clause is the whole definition. If you pay the other person and she agrees, the effect is a purchase, not an externality, which is why theft has an external effect but buying the same item does not.

Externalities come in two flavors. A positive externality benefits others who never paid you for it: a pretty garden the neighbors enjoy, or living among people who can all read and write the same language. That last benefit is so valuable to everyone that we make school attendance compulsory and subsidize vaccination, precisely to call forth more of it. A negative externality harms others without compensating them: blasting your stereo at the neighbors, tossing litter on their land, or eating a raw-onion sandwich in close conversation. Many small negative effects we tolerate, since stamping them out by law would cost more than they are worth, which is why a neighbor’s leaf smoke and ordinary traffic noise stay legal. Custom, etiquette, and the fear of being snubbed do a great deal of policing that no statute could afford.

The deep point is where these spillovers come from. You do not bear all the costs of an action when the thing you damage is not clearly owned by anyone. A steel mill that fouls a river or a refinery that degrades the air is using a resource nobody holds an enforceable, transferable right to. So we can be precise about what pollution really is: using a resource nobody owns and paying nothing for it. That diagnosis is the engine of the whole topic. If the air over your land were yours to defend, a neighbor who wanted to dump smoke on it would have to pay you, and that payment would force him to weigh the cost first. The cost would be internalized, borne by the actor who created it. Externalities are not a mysterious flaw in markets; they are the predictable result of resources no one owns, and the cure is to supply the missing ownership or a price that stands in for it.

That lets us be sharp about the difference between private cost and social cost. Every cost is ultimately borne by some person, so the social cost of an action is the sum of all the private costs it imposes, on whoever bears them. When the actor bears all of those costs himself, his private cost already equals the social cost, and his decision takes everything into account. An externality is the case where he does not: he escapes some of the cost, so social cost exceeds the private cost he feels, and he does too much of the activity. A working remedy, whether an assigned right, a charge, or a permit, loads the missing cost back onto him until his private cost equals the social cost again. That is all “internalizing” means.

One more distinction keeps you out of a common trap. The harms above are physical externalities, real damage to resources someone owns, and serious ones may be made illegal. But a second kind looks similar and is no wrong at all. A pecuniary externality is a hit to someone’s market value with no physical damage behind it. When a better textbook is published, it drains sales from the worse ones, yet their publishers are not entitled to compensation. No one owns a particular market value; values are nothing more than what others will offer, and you have no right to make them keep buying at yesterday’s price. A better product that ruins a rival is not an externality to correct. It is competition doing its job, letting preferred goods displace less-preferred ones. Treating ordinary competitive losses as if they were pollution is a common error in policy debate.

Economics Versus the Environment Is a False Issue

People talk as if there were a war between the economy and the environment, with one side bound to win and the other to lose. There is no such war. Everyone would like cleaner air and safer surroundings, and everyone would also like more income and the goods it buys. The honest question is never which side should triumph. It is the trade-off: more of one means less of the other, and we have to choose where to stand.

Consider the activist who fumed that a man fined for relieving himself in a river is punished while the factory polluting the same river is not, that we jail muggers but let “smoggers” walk free. The complaint has a moral ring, but it overlooks something basic. The factory’s pollution is the unwanted byproduct of producing things people value; the mugger produces nothing for anyone. Cars and planes carry exhaust, steelmaking gives up quiet and rest, oil wells smell, and all of it is part of the cost of a life that is more than Spartan. To condemn the activities with the largest costs is to forget they may also yield the largest benefits. The smogger, unlike the mugger, hands society real output along with the smoke.

So what should the activist have demanded? Not prohibition, and not the silence of the status quo, but a price. The constructive complaint is that we have not made polluters pay for the right to pollute and so bear the full cost of what they do. Put a price on polluting and people pollute less wherever the gain from the activity is worth less than the harm. Notice the two failure modes this avoids. A price of zero, the rule we mostly live under, lets people pollute as if the air were free, because for them it is. A price of infinity, an outright ban, pretends the activity has no value worth keeping. Both are almost always wrong. The useful path runs between them, exposing the trade-off and pricing it, and economics takes no side on how clean we should ultimately want the world; it only insists the choice is real and must be made.

Coase: With Clear, Salable Rights, the Efficient Use Does Not Depend on Who Holds the Right

Suppose you want to put up a building that will block the view from my apartments next door. We could fight it out in court, or settle it ourselves with a trade, but only once we know who holds the right to the view. Say the law gives the view to me. If your profit from building exceeds the view’s worth to me, you buy the right from me, and the building goes up. Now say the law gives the right to build to you. If the view is worth more to me than your profit, I pay you to refrain, and the view stays. In whichever world the right starts, the building goes up when, and only when, it is worth more than the view. Which use of the land wins is the same either way; the initial assignment changes only who ends up richer, not what happens to the resource.

That is the Coasean result, named for the economist Ronald Coase: when rights are clearly assigned and freely salable, the parties bargain their way to the value-maximizing use, and the use that results does not depend on who was handed the right first. The right flows to whoever values it most, the way any good does in a trade. Two cautions keep this from being a fairy tale. First, the initial assignment still matters enormously to people, since it decides who is made richer. Second, bargaining only works when the parties are few and the rights are clear. When a refinery’s odor would settle over thousands of scattered households, striking a separate deal with each is hopelessly expensive and private bargaining stalls. That is the kind of situation that gets handed to a government agency instead, where we turn next.

Tradable Pollution Rights Apply the Gains From Exchange to the Right to Emit

When bargaining one-on-one is too costly, a market can still be built deliberately, by creating rights to pollute and letting firms trade them. Years ago Los Angeles capped the total pollutants its firms could emit and scheduled the cap downward over a decade. Each firm got an allowance, usually based on what it had been emitting, and, crucially, could sell that allowance to another firm. A market in pollution rights sprang up at once.

Watch what that market does, since you have seen it before. Picture two firms, a paint maker and a refiner, each starting with the same allowance, say twenty units of pollution apiece. The paint maker can earn enough from expanding output that producing more is worth more to him than the price of the rights he would need. The refiner sits in the opposite position: the rights are worth more to him sold than the extra output he would give up to keep them. So the paint maker buys, the refiner sells, and each keeps trading until the value of one more unit of output just matches the common price of a pollution right. Both come out ahead, and the fixed total of pollution now produces the largest possible value of goods, since the rights have flowed to where they are worth most.

It is the gains-from-exchange logic from earlier in the course, where two people each end up better off by swapping until their valuations meet, with one change of label: there it was personal worths of a good, here the marginal market values of output. Trading rights to pollute is exchange applied to the right to emit. And the Coasean punchline holds here too: as long as the rights are salable, the final allocation comes out the same no matter which firm got the allowances at the start. A frequent objection is that richer firms will simply buy up the rights, which is unfair. But wealth has nothing to do with how much a pollution right is worth to a firm at the margin; a deep pocket does not make a foolish purchase wise, and both the buyer and the seller of a right come out ahead, or they would not trade.

A tax can do related work. A levy on gasoline makes drivers bear part of the pollution their driving creates, nudging consumption down toward the point where the worth of the last gallon burned matches its full cost, cleaner air included. The honest difficulty is that no one knows the right level for such a tax: nobody can say whether the next reduction in pollution is worth what it would cost in pricier travel, so we cannot be sure any particular tax is too high or too low. Keep in view what even an imperfect tax is doing: putting a price on the use of a resource, the air, that would otherwise be used as if it were free. That is the same move as the permit market, reached by a blunter instrument.

We are reasoning verbally here, the way we have all term, not drawing supply-and-demand machinery for the tax or measuring its welfare loss as a shaded triangle. The intuition is what you owe: a price on an external harm, permit or tax, makes the actor bear the cost he was escaping and lets the right end up where it is worth most.

This first half has stayed with harms and benefits that can be tied to identifiable users. Part B asks what changes when use is shared, exclusion is difficult, or the resource is open to everyone.