This situation features an intersection of the residual demand curve and the normal demand curve, such that demand curves are (*) discontinuous, or kinked.
Franklin Fisher introduced so-called folk theorems to model this situation. The Lerner index for agents in this situation is given by "negative one divided by n times e," where e is an agent's demand curve. Most models of this situation differ in the assumption whether prices or quantities are set simultaneously. This situation features an intersection of the residual demand curve and the normal demand curve, such that demand curves are (*) discontinuous, or kinked. Finding Nash equilibria for this model can be done via the Bertrand, Cournot and Stackelberg models when n=2. Like monopolistic competition, suppliers in this situation may collaborate to form a cartel. For 10 points, name this situation in which there are only a few sellers.
Franklin Fisher introduced so-called folk theorems to model this situation.
oligopoly [accept duopoly at any point]