nopoly price. While such access would be beneficial to the monopolist's competitors, simply requiring that the monopoly be shared would provide no benefits to consumers, because the monopoly would be left intact without any improvements in price or output. Setting prices is not a function to which antitrust courts are institutionally well suited. If courts were to adopt a role in setting prices, they would be forced to address the problems of valuing assets, distinguishing between prudent and impru- dent investments, separating capital from operating expenses, allocating shared costs across multiple products, and determining the appropriate rate of return that have long plagued the administrative ratemaking process. This difficulty explains why the Supreme Court noted in United States V. Trenton Potteries Co. that '[t]he rea- sonable price fixed today may through economic and business changes become the unreasonable price of tomorrow" and warned against "placing on the government United States Nav. Co. V. Cunard S.S. Co., 284 U.S. 474 (1932); Far E. Conference V. United States, 342 U.S. 570 (1952); Fed. Mar. Bd. V. Isbrandsten Co., 356 U.S. 481, 497-99 (1958). 78 Posner (1976); Areeda and Hovenkamp (2008c); Hovenkamp (2005); Sullivan and Grimes (2006). Networks in Telecommunications in enforcing the Sherman Law the burden of ascertaining from day to day whether it has become unreasonable through the mere variation of economic conditions." The Court continued: [I]n the absence of express legislation requiring it, we should hesitate to adopt a construction making the difference between legal and illegal conduct in the field of business relations depend upon SO uncertain a test as whether prices are reasonable - a determination which can be satisfactorily made only after a complete survey of our economic organization and a choice between rival philosophies. (273 U.S. 392, 397-98 (1927)) Subsequent decisions by both the Supreme Court and lower courts have reiterated the difficulties that antitrust courts face in dete