The rule of reason and the fundamentals against more presumption-based illegality legal standards: highlights on CADE’s decisions on digital economy issues

Abstract This article advocates against more presumption-based illegality legal standards. The focus is on the Rule of Reason analysis, which is in line with CADE’s case laws for analysing unilateral conducts, distinguishing between restraints with an anti-competitive effect (or resulting in conduct likely to cause such injury) that are harmful to the consumer, and restraints stimulating competition that are in the consumer’s best interest. In this sense, the article recalls some basic concepts, such as market power, dominant position, concentration indexes, and its interactions, since the recent discussions appear to have forgotten its basics. Moreover, a brief analysis of CADE’s procedures and the Brazilian Competition system, especially the analyses of unilateral conduct cases, is made in order to present a background for the readers. At the end, we report three digital antitrust cases judged by Cade to demonstrate the steps used by the authority in order to reach a decision on the case. In a nutshell, CADE has not shifted the analysis of unilateral conduct from the use of the rule of reason to a more presumption-based illegality approach.