Tacit collusion or parallel behaviour in oligopolistic markets? The two faces of Janus

Abstract

ABSTRACTA fundamental step in the assessment of antitrust law cases examined by National Competition Authorities (NCAs) is to detect and penalize anti-competitive behaviour (e.g. cartel agreements, secret agreements and tacit agreements). However, this is not an easy task for NCAs since the boundaries between non-explicit (tacit) collusion and parallel behaviour in oligopolistic markets under Bertrand competition are often vague. The scope of this paper is twofold. On the one hand, it aims to cast light on the role of economic analysis in tacit collusion cases by introducing the main quantitative techniques used in antitrust policy. In this way, it contributes to the literature by highlighting the role of economic analysis blended by the use of modern econometric techniques in unveiling the tacit collusion mechanism. On the other hand, it delves into discussions of Greek competition law matters by analysing in depth a tacit collusion case from the petroleum industry.