Judicial review in EU merger control towards deference on issues of law?

It is difficult to disentangle, in EU merger control, between issues of law (subject to full review by the EU courts) and complex economic assessments (controlled for manifest errors). This article discusses, and puts in context, the judgement of the Court of Justice in CK Telecoms. It explains why some of the interpretative choices made by the ECJ open the door to the transformation of the nature and intensity of judicial review in EU merger control. Where the meaning of an interpretation of a legal concept can only be figured out ex post (that is, after performing complex assessments), the control of administrative action may become, de facto, deferential and process-oriented (as opposed to substance-oriented). Leaving constitutional considerations aside, this shift would have the advantage of giving the European Commission the necessary policy space to test new doctrines and act nimbly in a changing economic and technological landscape. On the other hand, it may come at the expense of legal certainty and may not necessarily increase the quality of decision-making.