The anticompetitive effect is assessed in a market context. However, a restriction of competition infringes Article 101 TFEU even if the effect is produced on a different market to the one on which the undertaking is established.

It is not necessary for the restriction to have an adverse effect on an existing situation of competition (existing competition) for it to be caught by the prohibition, it is sufficient that it prevents future competition (potential competition). There are different degrees of probability of affecting potential competition. Harm to potential competition is always sanctioned when it is certain. This is generally the case for the ab initio creation of an exclusive trading agreement: unless it can be assumed that no other undertaking could have ensured the distribution of the products, the producer that uses an exclusive distributor inevitably restricts competition that could have existed between distributors.

EU law sometimes goes further and prohibits purely potential anticompetitive effects. According to the Commission, to establish an anticompetitive effect, it is sufficient that due to their experience and capacity, parent companies “might well have [been] led” to directly compete with one another with regard to the product in question, even though they had abandoned all individual research in that domain due to the amount of risk capital which would have to be invested and the technical skills and the possible length of time which would be required before the development could reach a stage where a commercially viable production might result. More recently the EU court has held that potential competition exists if there remains real and concrete – and not merely abstract and theoretical – opportunities for undertakings to compete with each other or for a new entrant to penetrate the market and compete with the established undertakings without any requirement to demonstrate with certainty that the undertakings would have entered the market and that that entry would inevitably have been successful.