res. The FCC was concerned that as long as the incumbent remained dominant, it continued to possess sufficient market power to charge supracompet- itive prices. The FCC was also concerned that dominant carriers might engage in predatory pricing. Regulators were thus simultaneously concerned that dominant firms might charge prices that were either too high or too low (FCC 1980d). The most prominent example of asymmetric rate regulation was with respect to long distance during the 1980s, during which time competition was just beginning become established. For example, until 1987, the FCC required AT&T to pay access charges to local telephone companies that were 55 percent higher than those paid by other long-distance carriers (FCC 1983c). 26 In addition, the FCC exempted new long distance companies, such as MCI and Sprint, from most tariffing require- ments, while continuing to subject AT&T to rate regulation until its dominance over the long distance market dissipated in 1995 (FCC 1995e). As noted in Chapter 4, the courts invalidated the FCC's detariffing decisions, ruling that the agency lacked the power to exempt any long-distance carriers from rate regulation. The 1996 Act gave the FCC the discretion to forbear from enforcing regulations it found to be unnecessary to protect consumers or to promote the public interest (47 U.S.C. $ 160). The FCC exercised this new authority to forbear from enforcing the tariffing requirements against long-distance carriers (FCC 1996d). This time, the decision was upheld by the courts (MCI WorldCom, Inc. V. FCC, 209 F.3d 760 (D.C. Cir. 2000)). In addition, the FCC also attempted to facilitate entry by new long distance companies by requiring AT&T to lease portions of its long-distance network to its competitors. Although the FCC initially invoked a number of different rationales, 24 See, e.g., Bonbright (1961); Temin (1987). 25 Indeed, some commentators have suggested that the FCC's regulatory efforts did more to promote long distance competition than did technological change. Th