30 the oxford introductions to u.s. law: property
• Accession
The acquisition principles we’ve seen thus far all involve someone performing some action, whether taking possession of something previously unowned, discovering it, or creating it. With the principle of accession, the emphasis is on status rather than action. Accession assigns unowned or contested objects to the owner of property that has the most prominent connection to the contested object. In other words, accession uses ownership of one thing to establish ownership over yet another thing.
A number of legal doctrines incorporate the principle of accession. One folksy example is the rule of increase. Baby animals are owned by the owners of the baby’s mother. A number of factors support this rule: the mother-offspring bond, the need for care of young animals by their mothers, and the ease of identifying the mother. The rule is recognized in all legal systems we know of, and admits of few exceptions. Even if the father is a prize-winning bull, absent a contract, the owner of the mother nevertheless gets the calf.
Another example of the principle of accession is a doctrine that is called, somewhat confusingly in American law, “accession.” (The Romans called this the doctrine of specificatio, and it might be advisable to revive this term in the interest of reducing confusion.) Under this doctrine, if one mixes one’s labor with some thing owned by someone else, one gets to keep the improved thing—not always, as this would be the worst sort of invitation to thieves and intermeddlers. For this doctrine of accession to apply, several tests or factors come into play. The degree of transformation of the object is important. The more difficult it is to identify the original object in the final product, the more likely it is that courts will award the final product to the laborer. The classic example is pressing grapes into wine. The comparison of relative values also matters. The more value added by the labor, the greater the chances the laborer will be given the final product. Thus, if one makes barrel hoops from trees one does not own, and the value of the hoops is 28 times the value of the standing trees when they were cut down, the improver can
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keep the hoops.17 Finally, to reflect the worry about destabilizing the system of ownership, only those who in good faith mistakenly mix their labor with an owned thing can invoke the doctrine of accession. Courts take a dim view of bad faith improvers, generally making bad faith a flat bar to accession. If under these tests the improver wins, the improver must compensate the owner of the original object in the amount of the value of unimproved thing or furnish the equivalent in kind. If the owner of the original object wins, however, the laborer can at most hope to make a (difficult) claim for restitution for the value of the labor.
Wild animal cases also feature a version of the principle of accession, which is variously called the doctrine of ratione loci (by reason of place) or ratione soli (by reason of the ground). When this doctrine applies, wild animals that are captured are awarded to the owner of the land on which the capture occurs, not the first possessor. Ownership of one thing, the land, gives ownership of another thing, the animal—another example of the broader principle of accession. The court in Pierson v. Post neatly dodged this doctrine by assuming that the place where the fox was captured was a wild and unpossessed beach.
There is an even more sweeping version of this instance of the principle of accession: the ad coelum doctrine. Under the ad coelum doctrine, ownership of the surface brings along with it ownership of the air space and the subsurface in a column or carrot of space running upward and downward from the surface boundaries. “Ad coelum” is short for “Cujus est solum, ejus est ad coelum et ad inferos,” which means “one who owns the soil owns also to the sky and to the depths.” The law of trespass crucially relies on the bright line furnished by the ad coelum doctrine in order to define an invasion. This doctrine allows buildings to include both foundations and basements and to rise to more than minimal height. Absent special agreements, the ad coelum doctrine also determines the ownership
17. Wetherbee v. Green, 22 Mich. 311 (1871).
32the oxford introductions to u.s. law: property
of minerals (even of caves), and at one time landowners argued that it potentially applied to airplane overflights.
A moment’s thought reveals the pointless chaos that would ensue from allowing land owners to block all airplane (not to mention spaceship) flights in the column of space defined by a literal application of the ad coelum rule. Instead, the law makes an exception to the ad coelum rule for airplane overflights where the owner is not actually using the space through which the airplane flies. This exception to the ad coelum doctrine can be rationalized in a variety of ways, most usually by recognizing public rights in a navigation (or in this case “avigation”) servitude.18 We return to public rights in the next chapter. Low-flying airplanes might be nuisances, but as we will see, nuisance—unlike the simple ad coelum-based law of trespass—requires proof of injury and is not nearly as strict.
Other examples of the principle of accession include accretion (under which land is augmented by alluvial deposits left by the ocean or a river), the principle that interest earned on a fund of money belongs to the owner of the principal, and the law of fixtures. Fixtures arise in a wide variety of situations. When A sells premises to B, or C leases from D, or E mortgages land when borrowing from F, there is a question as to whether certain items, such as appliances, mirrors, drapes, and so forth, go with the premises or are personal property that the seller, lessee, or mortgagor can take away. Absent a special agreement, the law of fixtures determines whether the item should stay or go. Intent matters, but not a hidden subjective intent. Custom can be a guide: Is this item something people expect to take with them or not? This can change: Bathtubs at various times have been considered separate or built in. Being physically attached (“bolted”) makes something more likely to be a fixture. If a mirror is affixed to a wall, especially if damage would be caused by its removal, it is a fixture. Likewise, if something is specially suited or custom-built to the premises, it is likely to stay.
18. See United States v. Causby, 328 U.S. 256 (1946).
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Courts also look to the identity of the party who provided the improvement for the improver’s likely intentions as manifested by objective acts. Thus, owners are more likely to be presumed to wish to “enrich the freehold,” as they say, than are tenants. So, if an owner builds custom book shelves that are not bolted but fit into a special niche, the owner might be considered to have made a fixture; but if a tenant built the shelves the tenant might be allowed to remove them at the end of the lease.
Accession, then, is a very general part of the law. Based on considerations of salience (e.g., smaller and less valuable goes with bigger and more valuable), accession allows the rich to get richer as it were. In this sense accession, like first possession, creation, and discovery, is a principle of acquisition.19 But by solving the question of what-goes-with-what, accession can also be regarded as a principle of asset definition. If property is a right to a thing, then the principle of accession goes a long way toward telling us what a thing is. Even with other principles of acquisition, like first possession, when someone acquires a thing we need to know what it is. Why can’t I acquire rights to the ocean by pouring a can of tomato juice in it (as Robert Nozick famously asked)?20 Because tomato juice neither forms the majority of the value of the ocean-tomato juice mixture nor transforms the ocean. Accession does not apply. So even when one acquires an unowned thing by a Lockean process of mixing labor, we need something like accession to tell us what (and how much) one has thereby acquired. Much of the time we can implicitly identify a thing, but in cases of doubt the principle of accession—often through one of the specific doctrines such as increase, and so forth—is there to help us decide what is the “thing.”
19.Thomas W. Merrill, Accession and Original Ownership, 1 J. Legal Analysis 459 (2009).
20.Robert Nozick, Anarchy, State and Utopia 175 (1974).