Access Pricing: A Comparison Between Full Deregulation and Two Alternative Instruments of Access Price Regulation, Cost-Based and Retail-Minus

In this paper we compare two instruments of access price regulation, cost-based and retail-minus, with the full deregulation hypothesis. We consider an upstream monopolist firm that sells a vital input to an independent firm and to a subsidiary firm in the downstream market. We conclude that the retail-minus regulation avoids foreclosure and leads to better results than cost-based regulation in terms of investment level and consumer surplus. Moreover, retail-minus regulation allows a higher consumer surplus than deregulation of access price as long as the regulator carefully defines the retail-minus instrument. We also compare retail-minus regulation with the Efficient Component Pricing Rule and we conclude that the two mechanisms can lead to different results.