Property: A Bundle of Sticks or a Tree?
di Robilant, Anna, Vanderbilt Law Review
In 1973 John Henry Merryman noted that property law is a largely unexplored field of comparative study.1 According to Merryman, common lawyers and civilians have long viewed their respective property systems as radically different and hardly comparable. In Merryman's words, the civil law is a law of "ownership," while the common law is a law of "estate."2 Civil law systems conceive of property as ownership, as holistic dominion: exclusive, single, indivisible, and different in nature from lesser property interests.3 By contrast, property in the common law is pluralistic and fragmented, having at its core the estates system and the many ways of carving up lesser property interests, from life estates to defeasible fees and future interests.4
Forty years have passed since Merryman's observations. Comparative property law is still a largely unexplored field, and civil law property and common law property are still perceived as fundamentally different. In the United States, every first-year law student learns that property is a "bundle of sticks." Introduced by Hohfeld, and further developed by the realists, the bundle of sticks concept characterizes property as a bundle of entitlements regulating relations among persons concerning a valued resource.5 The metaphor suggests that the bundle is malleable (i.e., that private actors, courts, and lawmakers may add or remove sticks, and that the bundle structures relations among persons, only secondarily and incidentally involving a thing). By contrast, in civil law countries, a law student may easily graduate without having ever heard that property is a bundle of rights. By and large, civil lawyers still view property as ownership.6 For civil law jurists, property is still a coherent and monolithic aggregate of entitlements over a thing, giving the owner an ample sphere of negative freedom (i.e., ample power to use the thing free from interference by nonowners or by the state).7
This conventional picture of comparative property raises a number of questions. Are Europeans actually unsophisticated old-style conceptualists who simply missed the realist revolution in property law? Furthermore, are the bundle of sticks concept and the ownership concept the only models to have been developed in the history of Western property law?
This Article provides a new answer to both questions. It argues that Europeans had their own realist revolution in property law. Further, it argues that the concept of property this realism ushered in, which I call the "tree" concept of property, provides a better way of understanding property than either the bundle of sticks model or the ownership model.8
The tree concept of property was developed by French and Italian jurists at approximately the same time Hohfeld and the realists invented and popularized the bundle of sticks concept. It rests on similar intuitions but still differs significantly. The tree concept views property as a tree with a trunk-representing the core entitlement that distinguishes property from other rights-and many branches-representing many resource-specific bundles of entitlements. The trunk of the tree is the owner's entitlement to control the use of a resource, mindful of property's "social function." For the theorists of the tree model, the social function of property evokes a plurality of values: equitable distribution of resources, participatory management of resources, and productive efficiency. The branches of the property tree are the multiple resource-specific property regimes present in modern legal systems: family property, agricultural property, affordable-housing property, industrial property, etc. Each of these branches requires a different balance of the plural values evoked by the social function of property, which is often translated as the many resource-specific bundles of entitlements.
The tree model of property has received virtually no attention by historians and comparativists. …