icing, con- verging telecommunications technology is vitiating the justification for setting rates according to cost-based methodologies. Once competition leads to market bench- marks, continued reliance on cost-based methodologies will be improper, under precedent. 3. Partial Takings of Utility Property The Supreme Court's takings jurisprudence recognizes that government compen- sation should generally reflect the earning potential of the property taken. The government need not compensate for a property's going concern value when it takes the entire fee and divests the current owner of title. As the Court explained in Kimball Laundry, "the denial of compensation in such circumstances rests on a very concrete justification: the going-concern value has not been taken." In such circumstances, "only the physical property has been condemned, leaving the owner free to move his business to a new location." The Court further reasoned that "there is no more reason for a taker to pay for the business' going-concern value than there would be for a purchaser to pay for it who had not secured from his vendor a covenant to refrain from entering into competition with him" (338 U.S. at 11; see also Gen. Motors, 323 U.S. at 379). Nonetheless, the Court identified two circumstances in which compensation for the going-concern value is appropriate. The first occurs when the government takes a public utility that possesses natural monopoly characteristics. "Since a utility cannot ordinarily be operated profitably except as a monopoly, investment by the former owner of the utility in duplicating the condemned faculties could have no prospect of a profitable return." In such cases, "[t]he owner retains nothing of the going-concern value that it formerly possessed." Therefore, because taking over a Networks in Telecommunications public utility "has the inevitable effect of depriving the owner of the going-concern value of his business," it is properly regarded as a taking for which compensation must be paid (338 U.S. at 12-13). The sec