e service provided to existing customers and for provisioning service to new cus- tomers. As Justice Breyer noted in Iowa Utilities Board, such an interface is likely to be particularly hard to police when the interface is complex and embedded in the middle of the network and the information requirements needed to regulate the interface are high (525 U.S. at 428-29). The breakup of AT&T provides a useful example. Implementing the divestiture decree's equal access mandate required the local telephone companies to redesign their switches SO that they could accommo- date multiple long distance providers, a process that entailed considerable cost and delay, as well as close regulation of both the price and nonprice terms and condi- tions of interconnection. Such oversight is particularly onerous when the interface and the information needed to implement it are complex (Faulhaber 2003). Furthermore, like any form of access, platform access requires direct regulation of prices in order to be effective, both in terms of nondiscrimination and in terms of price levels. For the reasons discussed in Chapter 4 and with respect to retail access, there is little reason to be optimistic that such regulation will prove beneficial. Most problematic is platform access's long-run impact on dynamic efficiency. As noted earlier, the primary policy goal should be to promote entry in those segments of the industry that are the least competitive. Only if competition in a particular segment proves unsustainable should policymakers pursue the second- best policy goal of promoting competition in complementary services. Once local telephone competition became possible, platform access became counterproduc- tive. Providers of complementary services were the natural strategic partners for new entrants in local telephone service. Platform access short-circuited this natural alliance by obviating the need for any complementary service providers to enter into such partnerships. At the time when most of the platform access mandates discussed abov