Property rights enable private persons or groups to control resources that might otherwise be controlled politically. That these rights (to use, sell, rent, profit from, and exclude others from) exist and are recognized means that rulers allow persons other than themselves to exercise control over valuables. In the abstract this is a puzzling fact. Why should rulers, with their supposed monopoly of force, leave great treasure in hands other than their own? Yet they do, and, presumably, they have good reason to do so. To identify their reason is to provide a partial explanation, at least, of the origin of property rights.

Traditional justifications of property rights ordinarily include some reference to origins. Unfortunately, many descriptions of origins devised for justificatory purposes are not historically or scientifically convincing and thereby weaken the justifications. To remedy this weakness, we set forth a positive explanation of rulers' motivations to grant property rights and citizens' motivations to petition for them and to respect them. We illustrate our theory with a contemporary example so that it, unlike most other discussions of origins, can be checked against easily available detail.

But first a caveat. Our purpose is not to debate the philosophical justification of rights. We recognize, of course, that despite our self-imposed restrictions, our theory may have implications for these justifications that depend crucially on incomplete descriptions of origins.