Marktdefinitie

Marktdefinitie is the process used in competition policy and economic analysis to determine the relevant market for assessing competitive effects. It identifies the scope of competition in two dimensions: the product market, which includes the types of goods or services considered interchangeable, and the geographic market, which encompasses the area where those goods or services are sold at similar prices and conditions.

The definition rests on substitutability: if consumers would switch to close substitutes in response to a price change, those substitutes belong to the same market. Analysts consider both demand-side substitution (how consumers react to price changes) and supply-side substitution (how firms might adapt production or sourcing). A common method is the hypothetical monopolist test, or SSNIP test, which asks whether a small but significant and non-transitory price increase would be profitable for a monopolist in that market. If many substitutes exist, the market is defined more broadly; if not, it is defined more narrowly.

After defining the market, authorities may use it to assess competition using tools such as concentration measures (for example, HHI), potential competitive constraints, and the effects of mergers or practices. The market definition is a starting point, not a verdict, and may be adapted to sector-specific realities, including digital markets and two-sided platforms. In the Netherlands, as in broader EU competition policy, marktdefinitie informs assessments by agencies such as the ACM and the European Commission, guiding subsequent analyses of competitive effects and remedies.