Encroachment, Adverse Possession, and Labor Theory


John Locke's theory of property is assumed to refer to one of two alternatives — a labor-desert theory and a libertarian alternative. Locke's theory of property is also assumed to be rigid and extreme because it requires that property rights be protected no matter what the social consequences. Virtually all property scholars disregard a far suppler and more practical understanding of Lockean labor theory, consistent with medieval and early Enlightenment natural law reasoning, called here "productive labor theory." This Article restates the case for productive labor theory, distinguishes it from its libertarian and labor-desert alternatives, and shows how it integrates consequentialist practical reasoning into the effort to secure natural property rights. The Article illustrates using the prima facie case for trespass to land, the defense for adverse possession, and the principles that specify whether continuing encroachments are rectified by permanent damages or injunctive relief.