A monopoly is a market in which one person or company is the only supplier of a particular good or service. A monopoly is characterized by a lack of economic competition to produce a particular thing, a lack of viable substitute goods, and the possibility of a high monopoly price well above the seller's marginal cost that leads to a high monopoly profit. The verb monopolise or monopolize refers to the process by which a company gains the ability to raise prices or exclude competitors. In economics, a monopoly is a single seller. In law, a monopoly is a business entity that has significant market power, that is, the power to charge overly high prices, which is associated with unfair price raises. Although monopolies may be big businesses, size is not a characteristic of a monopoly. A small business may still have the power to raise prices in a small industry (or market).
A monopoly may also have monopsony control of a sector of a market. A monopsony is a market situation in which there is only one buyer. Likewise, a monopoly should be distinguished from a cartel (a form of oligopoly), in which several providers act together to coordinate services, prices or sale of goods. Monopolies, monopsonies and oligopolies are all situations in which one or a few entities have market power and therefore interact with their customers (monopoly or oligopoly), or suppliers (monopsony) in ways that distort the market.
Monopolies can be formed by mergers and integrations, form naturally, or be established by a government. In many jurisdictions, competition laws restrict monopolies due to government concerns over potential adverse effects. Holding a dominant position or a monopoly in a market is often not illegal in itself; however, certain categories of behavior can be considered abusive and therefore incur legal sanctions when business is dominant. A government-granted monopoly or legal monopoly, by contrast, is sanctioned by the state, often to provide an incentive to invest in a risky venture or enrich a domestic interest group. Patents, copyrights, and trademarks are sometimes used as examples of government-granted monopolies. The government may also reserve the venture for itself, thus forming a government monopoly, for example with a state-owned company.
Monopolies may be naturally occurring due to limited competition because the industry is resource intensive and requires substantial costs to operate (e.g., certain railroad systems).