 Another, related aspect is that the cost of enforcing property rights differs between cases, partly for technological, partly for legal and political reasons. That automobiles are private goods depends on the relatively cheap availability of suitable locks and also on the fact that the government enforces property rights in automobiles. If the price of locks were higher, or the government made it illegal to secure one’s car using a lock, or the government stopped prosecuting theft, automobiles would be “non-excludable” (Demsetz 1964).