Bottleneck Access with Structural Regulation and Endogenous Competition

In a simple model of network industry, where an upstream monopolist provides an essential input for downstream service supply, we analyze the competitive settings arising in the downstream market under alternative regulatory frameworks; we combine structural (i.e. vertical integration, functional/ownership separation) and conduct (discriminatory and nondiscriminatory access) regulatory remedies. Down- stream firms are characterized by different levels of cost e fficiency in the provision of the service. We show that the degree of heterogeneity in firms\u2019 cost efficiency is critical to the determination of the amount of competition that emerges in the downstream market, and of the efficiency of the industry. We show that i) when downstream firms are significantly heterogenous, discrimina tory access fees may be socially desirable and ii) vertical integration is always socially preferable