Access pricing: A comparison between full deregulation and two alternative instruments of access price regulation, cost-based and retail-minus

In this paper, two instruments of access price regulation, cost-based and retail-minus, are compared with the full deregulation hypothesis. For this purpose, a model that considers an upstream monopolist firm that sells a vital input to an independent firm and to a subsidiary firm in the downstream market is developed. The main conclusion of the paper is that 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.