Олигополия: рыночная структура и регулирование

Market dominated by a small number of sellers

An oligopoly is a market in which control over an industry lies in the hands of a few large sellers who own a dominant share of the market. Oligopolistic markets have homogenous products, few market participants, and inelastic demand for the products in those industries. As a result of their significant market power, firms in oligopolistic markets can influence prices through manipulating the supply function. Firms in an oligopoly are also mutually interdependent, as any action by one firm is expected to affect other firms in the market and evoke a reaction or consequential action. where oligopolists have their own market structure. In this situation, each company in the oligopoly has a large share in the industry and plays a pivotal, unique role. Many jurisdictions deem collusion to be illegal as it violates competition laws and is regarded as anti competition behaviour. The EU competition law in Europe prohibits anti competitive practices such as price fixing and competitors manipulating market supply and trade. In the US, the United States Department of Justice Antitrust Division and the Federal Trade Commission are tasked with stopping collusion. In Australia, the Federal Competition and Consumer Act 2010 has details the prohibition and regulation of anti competitive agreements and practices. Although aggressive, these laws typically only apply when firms engage in formal collusion, such as cartels. Corporations may often thus evade legal consequences through tacit collusion, as collusion can only be proven through direct communication between companies. Within post socialist economies, oligopolies may be particularly pronounced. For example in Armenia, where business elites enjoy oligopoly, 19% of the whole economy is monopolized, making it the most monopolized country in the region. Many industries have been cited as oligopolistic, including civil aviation, electricity providers, the telecommunications sector, rail freight markets, food processing, funeral services, sugar refining, beer making, pulp and paper making, and automobile manufacturing.

Perfect and imperfect oligopolies are often distinguished by the nature of the goods firms produce or trade in. A perfect (sometimes called a 'pure') oligopoly is where the commodities produced by the firms are homogenous (i. e., identical or materially the same in nature) and the elasticity of substitute commodities is near infinite. Generally, where there are two homogenous products, a rational consumer's preference between the products will be indifferent, assuming the products share common prices. Similarly, sellers will be relatively indifferent between purchase commitments in relation to homogenous products. In an oligopolistic market of a primary industry, such as agriculture or mining, commodities produced by oligopolistic enterprises will have strong homogeneity; as such, such markets are described as perfect oligopolies. Imperfect (or 'differentiated') oligopolies, on the other hand, involve firms producing commodities which are heterogenous. Where companies in an industry need to offer a diverse range of products and services, such as in the manufacturing and service industries, such industries are subject to imperfect oligopoly.

An open oligopoly market structure occurs where barriers to entry do not exist, and firms can freely enter the oligopolistic market. In contrast, a closed oligopoly is where there are prominent barriers to market entry which preclude other firms from easily entering the market. Entry barriers include high investment requirements, strong consumer loyalty for existing brands, regulatory hurdles and economies of scale. These barriers allow existing firms in the oligopoly market to maintain a certain price on commodities and services in order to maximise profits.

Collusion among firms in an oligopoly market structure occurs where there are express or tacit agreements between firms to follow a particular price structure in relation to particular products (for homogenous products) or particular transaction or product classes (for heterogeneous products). Interdependence in oligopolies is reduced when firms collude, because there is a lessened need for firms to anticipate the actions of other firms in relation to prices. Collusion closes the gap in the asymmetry of information typically present in a market of competing firms. One form of collusive oligopoly is a cartel, a monopolistic organisation and relationship formed by manufacturers who produce or sell a certain kind of goods in order to monopolise the market and obtain high profits by reaching an agreement on commodity price, output and market share allocation. However, the stability and effectiveness of a cartel are limited, and members tend to break from the alliance in order to gain short term benefits.

A full oligopoly is one in which a price leader is not present in the market, and where firms enjoy relatively similar market control. A partial oligopoly is one where a single firm dominates an industry through saturation of the market, producing a high percentage of total output and having large influence over market conditions. Partial oligopolies are able to price make rather than price take.

In a tight oligopoly, only a few firms dominate the market, and there is limited competition. A loose oligopoly, on the other hand, has many interdependent firms which often collude to maximise profits. Markets can be classified into tight and loose oligopolies using the four firm concentration ratio, which measures the percentage market share of the top four firms in the industry. The higher the four firm concentration ratio is, the less competitive the market is. When the four firm concentration ration is higher than 60, the market can be classified as a tight oligopoly. A loose oligopoly occurs when the four firm concentration is in the range of 40 60.