 Plainly private property and collective control are not all-or-nothing alternatives. In every modern society, some resources are governed by common property rules (e.g., streets and parks), some are governed by collective property rules (e.g., military bases and artillery pieces), and some are governed by private property rules (toothbrushes and bicycles). Also, there are variations in the degree of freedom that a private owner has over the resources assigned to him. Obviously, an owner’s freedom is limited by background rules of conduct: I may not use my gun to kill another person. These are not strictly property rules. More to the point are things like zoning restrictions, which amount in effect to the imposition of a collective decision about certain aspects of the use of a given resource. The owner of a building in an historic district may be told, for example, that she can use it as a shop, a home, or a hotel but she may not knock it down and replace it with a skyscraper. In this case, we may still say that the historic building counts as private property; but if too many other areas of decision about its use were also controlled by public agencies, we would be more inclined to say that it was really subject to a collective property rule (with the ‘owner’ functioning as steward of society’s decisions).