Markets for commodities such as wheat are examples of market systems that approach the perfect competition model. In market economies, there are a variety of different market systems that exist, depending on the industry and the companies within that industry. It is important for small business owners to understand what type of market system they are operating in when making pricing and production decisions, or when determining whether to enter or leave a particular industry.
Perfect competition is a market system characterized by many different buyers and sellers. In the classic theoretical definition of perfect competition, there are an infinite number of buyers and sellers. With so many market players, it is impossible for any one participant to alter the prevailing price in the market. If they attempt to do so, buyers and sellers have infinite alternatives to pursue.
A monopoly is the exact opposite form of market system as perfect competition. In a pure monopoly, there is only one producer of a particular good or service, and generally no reasonable substitute. In such a market system, the monopolist is able to charge whatever price they wish due to the absence of competition, but their overall revenue will be limited by the ability or willingness of customers to pay their price.
An oligopoly is similar in many ways to a monopoly. The primary difference is that rather than having only one producer of a good or service, there are a handful of producers, or at least a handful of producers that make up a dominant majority of the production in the market system. While oligopolists do not have the same pricing power as monopolists, it is possible, without diligent government regulation, that oligopolists will collude with one another to set prices in the same way a monopolist would.
Monopolistic competition is a type of market system combining elements of a monopoly and perfect competition. Like a perfectly competitive market system, there are numerous competitors in the market. The difference is that each competitor is sufficiently differentiated from the others that some can charge greater prices than a perfectly competitive firm. An example of monopolistic competition is the market for music. While there are many artists, each artist is different and is not perfectly substitutible with another artist.
Market systems are not only differentiated according to the number of suppliers in the market. They may also be differentiated according to the number of buyers. Whereas a perfectly competitive market theoretically has an infinite number of buyers and sellers, a monopsony has only one buyer for a particular good or service, giving that buyer significant power in determining the price of the products produced.