This paper examines the economic consequences of allocating common costs by (1) gross revenues, (2) directly attributable costs, and (3) relative output levels (such as ton-miles) to determine fully distributed cost prices for regulated firms. The analysis characterizes FDC tariffs, examining the nature of the economic inefficiency associated with the rules, and explains how opportunities for entry by unregulated firms might change if Ramsey optimal pricing were used instead of FDC pricing
