Glossary of competition terms

This Glossary was prepared by DG COMP and the OECD for non-competition specialists. Each term is enriched with references of national case laws from the e-Competitions Bulletin. (© European Union - © OECD)


Special case of oligopoly: industry structure with two sellers. In competition cases the term is often also used for situations where two main sellers dominate the competitive structure and a fringe of smaller sellers adapts to their behaviour. The two main sellers are then referred to as the duopoly.

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A duopoly is an industry consisting of two sellers. It is therefore a special case of oligopoly. In industrial organization economic theory, duopoly is often analysed as a simplified example of oligopoly behaviour.

See also oligopoly.