12.1 Monopolistic Competition Monopolistic competition-Market in which firms can enter freely,each producing its own brand or version of a differentiated product. Oligopoly-Market in which only a few firms compete with one another,and entry by new firms is impeded. Cartel-Market in which some or all firms explicitly collude, coordinating prices and output levels to maximize joint profits.12.1 Monopolistic Competition  Monopolistic competition - Market in which firms can enter freely, each producing its own brand or version of a differentiated product.  Oligopoly - Market in which only a few firms compete with one another, and entry by new firms is impeded.  Cartel - Market in which some or all firms explicitly collude, coordinating prices and output levels to maximize joint profits