ny facilities of its own had two choices. The most straightforward way was to invoke the resale provisions of the 1996 Act and purchase wholesale access to the entire network at wholesale prices. Regulators set wholesale access rates at 15-25 percent below full retail (Hazlett 2006). At the same time, resale access could be duplicated simply by using unbundled access to purchase all of the elements necessary to provide local service. In contrast to the top-down approach to wholesale access prices, in which wholesale access prices are based on deductions from full retail prices, UNE access prices are calculated from the bottom up based on the long-run incremental cost of particular network elements. Until the deregulation of mass market switching effectively abolished UNE-P in 2005, new entrants were able to leverage the differences in the pricing to obtain wholesale access at rates substantially below those regulators deemed appropriate. The opportunity for regulatory arbitrage will remain SO long as access mandates remain in place and differences in the methodologies for calculating access rates persist. Eventually, the advent of competition will obviate the need to harmonize these pricing regimes by eliminating the need for imposing access requirements in the first place. Networks in Telecommunications E. Markets and the Design of Networks In its 2003 Triennial Review, the FCC stated that in interpreting the access standards it would consider the standards of whether access was "necessary" for entrants and whether entrants' supply plans would be "impaired" otherwise. The FCC also considered the following desired outcomes in its unbundled access regulations: (1) "the rapid introduction of competition in all markets - whether the availability of an unbundled network element is likely to encourage requesting carriers to enter the local market in order to serve the greatest number of consumers as rapidly as possible," (2) "promotion of facilities-based competition, investment and innovation the extent to which the 