romote competi- tion in so-called "enhanced" telecommunications services (i.e., services that went beyond mere voice communication) by requiring that they be provided on a ver- tically disintegrated basis. As noted in Chapter 5, the digitization of telephone switches means that certain enhanced services, such as caller ID, call forwarding, and call waiting, are most efficiently provided through the data processing capac- ity already built into the switch itself. Forcing these services to be provided on a vertically disintegrated basis delayed introduction of these services by several years. Other efficiencies are more price-theoretic, such as the elimination of double marginalization or the rationalization of input substitution discussed in Chapter 4. To the extent that concerns about vertical exclusion are justified, this makes it quite likely that allowing some degree of vertical coordination will yield welfare benefits. Still other efficiencies relate to transaction costs, particularly in protecting against opportunistic behavior. The Supreme Court eventually embraced this emerging vision in its landmark decision in Continental T.V., Inc. V. GTE Sylvania, in which it accepted the reduction of the transaction costs needed to guard against opportunism as a pro-competitive business justification sufficient to support holding exclusivity agreements. In the 39 FCC (2005c); Woroch (2002a). 40 Ayres (1988); Salinger (1988); Hart and Tirole (1990); Klass and Salinger (1995); Riordan and Salop (1995); see also Krattenmaker and Salop (1986), conducting a similar analysis with respect to vertical restraints. For discussions of the potential efficiencies associated with vertical exclusion in the context of the essential facilities doctrine, see Werden (1987); Gerber (1988); Areeda and Hovenkamp (2008c). Antitrust as Applied to Network Industries process, the Court rejected buyer and trader freedom as independent values that justify regulatory intervention even in the absence of any showing of harm to competition (433 U.S.