oligopoly model in which firms are able, but not obliged, to charge subscribers for receiving and placing calls, may …

prices and advertising tariffs. We build on the work of Gabszewicz, Laussel and Sonnac (2001, 2002), whose model we take as …), cover prices are positive and the minimal differentiation outcome does not depend on the size of the advertising market. We … to cooperate in setting cover prices and advertising tariffs but not the editorial line …

existing models of asymmetric duopoly and symmetric oligopoly where consumer expectations about market shares are passive. We …