Various proposals to restructure electric power transmission systems for an open and competitive market rely on concepts such as nodal prices, congestion revenues, transmission rights, etc. Implicit assertions are made concerning the regulation of transmission access, properties of economic dispatch, and the operation of competitive power markets. In PWP-023, Wu, Varaiya, Oren, and Spiller formulate these "folk theorems" as explicit mathematical assertions, prove the ones that are true and present counterexamples to those that are not. The concept of contract network is a centerpiece in Professor William Hogan's recent proposal for establishing a Poolco in the operation of a restructured electric utility. The contract network is based on nodal pricing and transmssion capacity rights. In PWP-023, the authors provide a detailed analysis of these concepts and show that the use of nodal pricing for transmission systems and the assignment of transmission capacity rights are not compatible to the promotion of economic efficiency.