monopolistic competition

Short-run equilibrium of the company under monopolistic competition. The company maximises its profits and produces a quantity where the company's marginal revenue (MR) is equal to its marginal cost (MC). The company is able to collect a price based on the average revenue (AR) curve. The difference between the company's average revenue and average cost, multiplied by the quantity sold (Qs), gives the total profit. A short-run monopolistic competition equilibrium graph has the same properties of a monopoly equilibrium graph. Long-run equilibrium of the company assuming monopolistic competition. The company still produces where marginal cost and marginal revenue are equal; however, the demand curve (MR and AR) has shifted as other companies entered the market and increased competition. The company no longer sells its goods above average cost and can no longer claim an economic profit.

Monopolistic competition is a type of imperfect competition such that there are many producers competing against each other but selling products that are differentiated from one another (e.g., branding, quality) and hence not perfect substitutes. For monopolistic competition, a company takes the prices charged by its rivals as given and ignores the effect of its own prices on the prices of other companies. If this happens in the presence of a coercive government, monopolistic competition may evolve into government-granted monopoly. Unlike perfect competition, the company may maintain spare capacity. Models of monopolistic competition are often used to model industries. Textbook examples of industries with market structures similar to monopolistic competition include restaurants, cereals, clothing, shoes, and service industries in large cities. The earliest developer of the theory of monopolistic competition is Edward Hastings Chamberlin, who wrote a pioneering book on the subject, Theory of Monopolistic Competition (1933). Joan Robinson's book The Economics of Imperfect Competition presents a comparable theme of distinguishing perfect from imperfect competition. Further work on monopolistic competition was performed by Dixit and Stiglitz who created the Dixit-Stiglitz model which has proved applicable used in the subtopics of international trade theory, macroeconomics and economic geography.