ous, welfare analysis of network diversity requires balancing the short-run static efficiency losses from allowing network owners to earn short-run supracompetitive profits against the long-run dynamic efficiency gains resulting from stimulating the entry of competing net- works. In short, whether network neutrality or network diversity would lead to a more socially beneficial outcome is a context-specific question that cannot be answered a priori. The absence of simple policy inferences renders the regula- tory decision whether to impose network neutrality quite complex. Indeed, net- work neutrality proponents have suggested that many of the problems associ- ated with network neutrality can be addressed through other means (Lessig 2002; Wu 2004). There are, however, a number of institutional considerations that suggest that network diversity might well be the better approach. To the extent that regulatory solutions take the form of ex ante rules, they are poorly suited to the context- specific determinations suggested by network diversity theory. A presumption that discriminatory access arrangements are anticompetitive would contradict the grow- ing empirical literature indicating that vertical integration and vertical contractual restraints tend to promote consumer welfare. Such a presumption would also pre- vent network owners from experimenting with network diversity, because they would presumably be foreclosed from adopting any practice that deviated from interoperability and interconnectivity unless they could demonstrate clear benefits. Network neutrality proponents concede the difficulties in distinguishing practices that are economically justified from those that will harm competition. Because of the inherent ambiguity of many business practices, competition policy's usual response is not to put the burden of demonstrating economic benefits on parties who wish to adopt a practice, but rather to place the burden on the opponents of the practice and to permit the practice to occur until opponents can demon