Monopolistic competition

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 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. 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.
Monopolistically competitive markets have the characteristics following:

There are many producers and many consumers in the market, and no business has total control over the market price.
Consumers perceive that there are non-price differences among the competitors' products.
Companies operate with the knowledge that their actions will not affect other companies' actions.
There are few barriers to entry and exit.
Producers have a degree of control of price.
The principal goal of the company is to maximize its profits.
Factor prices and technology are given.
A company is assumed to behave as if it knew its demand and cost curves with certainty.
The decision regarding price and output of any company does not affect the behaviour of other companies in a group, i.e., effect of the decision made by a single company is spread sufficiently evenly across the entire group. Thus, there is no conscious rivalry among the companies.
Each company earns only normal profit in the long run.
Each company spends substantial amount on advertisement. The publicity and advertisement costs are known as selling costs.

The long-run characteristics of a monopolistically competitive market are almost the same as a perfectly competitive market. Two differences between the two are that monopolistic competition produces heterogeneous products and that monopolistic competition involves a great deal of non-price competition, which is based on subtle product differentiation. A company making profits in the short run will nonetheless only break even in the long run because demand will decrease and average total cost will increase, meaning that in the long run, a monopolistically competitive company will make zero economic profit. This illustrates the amount of influence the company has over the market; because of brand loyalty, it can raise its prices without losing all of its customers. This means that an individual company's demand curve is downward sloping, in contrast to perfect competition, which has a perfectly elastic demand schedule.

Characteristics

There are eight characteristics of monopolistic competition :

Companies are price setters.
Free movement of resources from one company to another.
Product differentiation.
Many companies.
Freedom of entry and exit.
Independent decision making.
Some degree of market power.
Buyers and sellers do not have perfect information.
Product differentiation

MC companies sell products that have real or perceived non-price differences. Examples of these differences could include physical aspects of the product, location from which it sells the product or intangible aspects of the product, among others. However, the differences are not so great as to eliminate other goods as substitutes. In technical terms, the cross price elasticity of demand between goods in such a market is large and positive. MC goods are best described as close but imperfect substitutes. The goods perform the same basic functions but have differences in qualities such as type, style, quality, reputation, appearance, and location that tend to distinguish them from each other. For example, the basic function of motor vehicles is the same—to move people and objects from point to point in reasonable comfort and safety. Yet there are many different types of motor vehicles such as motor scooters, motor cycles, trucks and cars, and many variations even within these categories.

Many companies

There are many companies in each MC product group and many companies on the side lines prepared to enter the market. A product group is a "collection of similar products". The fact that there are "many companies" means that each company has a small market share. This gives each MC company the freedom to set prices without engaging in strategic decision making regarding the prices of other companies and each company's actions effect the market negligibly. For example, a company could reduce prices and increase sales without fear that its actions will prompt retaliatory responses from competitors.
The number of companies that an MC market structure will support at market equilibrium depends on factors such as fixed costs, economies of scale, and the degree of product differentiation. For example, the greater the fixed costs, the fewer companies the market will support.

Freedom of entry and exit

Like perfect competition, with monopolistic competition also, the companies can enter or exit freely. The companies will enter when the existing companies are making super-normal profits. With the entry of new companies, the supply would increase which would reduce the price and hence the existing companies will be left only with normal profits. Similarly, if the existing companies are sustaining losses, some of the marginal companies will quit. It will reduce the supply due to which price would rise and the existing companies will be left only with normal profit.

Independent decision-making

Each MC company independently sets the terms of exchange for its product. The company gives no consideration to what effect its decision may have on its competitors. The theory is that any action will have such a negligible effect on the overall market demand that an MC company can act without fear of prompting heightened competition. In other words, each company feels free to set prices as if it were a monopoly rather than an oligopoly.

Market power

MC companies have some degree of market power, although relatively little. Market power means that the company has control over the terms and conditions of exchange. All MC companies are price makers. An MC companies can increase its prices without losing all its customers. The company can also decrease prices without triggering a potentially ruinous price competition with other companies. The source of an MC company's market power is not barriers to entry since they are low. Rather, an MC company has market power because it has relatively few competitors, those competitors do not engage in strategic decision making and the companies sells differentiated product. Market power also means that an MC company faces a downward sloping demand curve. In the long run, the demand curve is very elastic, meaning that it is sensitive to price changes, although it is not completely "flat". In the short run, economic profit is positive, but it approaches zero in the long run.

Imperfect information

No other sellers or buyers have complete market information, like market demand or market supply.

Market Structure	Number of firms	Market power	Elasticity of demand	Product differentiation	Excess profits	Efficiency	Profit maximization condition	Pricing power
Perfect competition	Infinite	-	Perfectly elastic	-	Short term yes, long term no	Yes	P=MR=MC	Price taker
Monopolistic competition	Many	Low	Highly elastic	High	Short term yes, long term no	No	MR=MC	Price setter
Monopoly	One	High	Relatively inelastic	Absolute	Yes	No	MR=MC	Price setter

Inefficiency

There are two sources of inefficiency in the MC market structure. The first source of inefficiency is that, at its optimum output, the company charges a price that exceeds marginal costs. The MC company maximises profits where marginal revenue equals marginal cost. Since the MC company's demand curve is downwards-sloping, the company will charge a price that exceeds marginal costs. The monopoly power possessed by a MC company means that at its profit-maximising level of production, there will be a net loss of consumer surplus. The second source of inefficiency is the fact that MC companies operate with excess capacity. That is that the MC company's profit-maximising output is less than the output associated with minimum average cost. Both an MC and PC company will operate at a point where demand or price equals average cost. For a PC company, this equilibrium condition occurs where the perfectly elastic demand curve equals minimum average cost. An MC company's demand curve is not flat but is downward-sloping. Thus, the demand curve will be tangential to the long-run average cost curve at a point to the left of its minimum. The result is excess capacity.