trust,2: 23 UNE access, 24 and multiple ISP access to cable modem systems25 has long emphasized how regimes mandating interconnection and standardization can discourage entry into the last mile. As a result, network neutrality would appear to conflict directly with the goal of dynamic efficiency and would instead be the source of, rather than the solution to, market failure. Conversely, embracing a network diversity principle promises to promote competition in the last mile and thereby alleviate the central issue confronting broadband policy. The reasons that mandating interconnection is potentially problematic from the standpoint of dynamic efficiency can best be explained in terms of the hypothetical example based on Terminal Railroad discussed above. Suppose that access to the bridge was not compelled and that rates were not regulated. Any supracompetitive returns earned by the owner of the existing bridge would signal that the market was in disequilibrium and would provide the incentive for anyone interested in building another bridge to do SO. In addition, the railroads that were unable to obtain access to the existing bridge would be clamoring for an alternative. They would thus represent the natural strategic partners for any would-be builder of another bridge. The situation changes dramatically if access to the bridge is compelled. Granting access lets the customers who would otherwise stand ready to invest in a new bridge off the hook, rescuing them from having to undertake the risks associated with investing in alternative capacity. At the same time, the would-be bridge entrant would also find entry less attractive. Knowing that it would be forced to share the new bridge with all comers at regulated prices weakens the incentives for it to construct another bridge. Indeed, rate regulation can deprive the new entrant of the returns 23 Areeda and Hovenkamp (2008c); Robinson (2002). 24 Hausman and Sidak (1999); Crandall and Hausman (2000); Jorde et al. (2000). 25 Yoo (2004a); Lopatka and Page (2001). The Re