Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This note extends the analysis of Armstrong, Doyle and Vickers [1996] to the case of retail price deregulation. It is shown (i) that the optimal access price may be above, below, or (in the linear case) equal to marginal cost, (ii) that optimal regulation of the margin between the retail price and the access price entails the ECPR, and (iii) that welfare and entrant profit are higher when the level of the access price, rather than the margin, is regulated.