ers will equal or exceed the costs to suppliers. The market price equals the marginal benefit of the good and thus indicates its economic value. Markets are the best mechanism for allocating network services, SO that from the point of view of efficiency, access transactions are preferable to mandatory access. It bears emphasis that markets are effective mechanisms for pricing not only physical products such as automobiles and food, but also services such as trans- portation or restaurant services. Many types of services are routinely purchased and sold. For example, video rental stores supply their customers with entertainment services corresponding to viewing a movie at home. Movie theaters provide similar entertainment services that require viewing the movie at the theater. Automo- bile renting and leasing companies supply customers with transportation services. Economic theory does not distinguish between the market allocation of physical products and the market allocation of services. Accordingly, markets can allocate network-generated services just as they do any other type of physical products or services. The theory of networks is highly useful for modeling network architecture and the boundaries of networks. The theory of networks also is useful for examining the various types of network services and the various types of access transactions. The structure of networks and their associated costs affect the costs of providing different types of network services. Network theory is useful for determining the costs of network facilities as well as the opportunity costs of providing different types of network services. Network theory is an analytical tool and as such it is neutral in terms of its implications for what type of pricing methodology should be used by regulators. Network theory can be applied to study total element long run incremental costs (TELRIC), the efficient component pricing rule (ECPR), or other pricing methodologies. Network theory does shed light on these methodologies, however. The struct