Pricing Transmission Constraints
Your editorial in the June 1, 1997 issue ("PJM's Brave New World," p. 4) provided a perceptive analysis of the Pennsylvania transmission pricing debate. As you point out, standard economics defines the value of a transmission constraint as the difference between the price of electricity on one side of the constraint and price on the other side. There can be no dispute over this statement; however, this straightforward theory is not always correctly applied.
In the case of electricity, the marginal running cost (or energy price) cannot be used to determine the value of a constraint.