The prohibition of single-firm market abuses: US monopolisation versus EU abuse of dominance

Together with the prohibition of multilateral anti-competitive practices, competition legal systems worldwide have a rule against unilateral anti-competitive behaviour by monopolists or dominant firms in the market. There is a broad consensus worldwide over the general idea of the need for competition law to police single-firm abuses whenever firms have achieved a position of strong market power. However, there are very relevant disparities in the formulation and implementation of the specific rules that countries around the world have enacted to tackle abuses coming from the single-handed concentration of economic power in the markets.

Aside from the legal specificities in the drafting of the prohibition of single-firm abuses in different countries, which—at the end—may not vary so much, most differences are explained and justified in the concrete context (ideological and historical) and institutional reality in which the prohibition is to be implemented and which may lead to similar cases reaching distinct outcomes.

To analyse the variations in the treatment of unilateral conduct in competition law requires looking both at the US and the EU experiences. These two legal systems have provided the source of inspiration in the adoption and enforcement of the prohibition elsewhere in the world.