Google as a de facto privacy regulator: analysing the Privacy Sandbox from an antitrust perspective

Now a multi-billion-dollar industry, online advertising is what funds free online content. At the core of this industry lies the ability to track users through various technical means, such as cookies, which has sparked privacy concerns, and is thus subject to a growing body of regulation. But the most important rules around tracking seem to come from a handful of large platforms who have assumed the role of a de facto privacy regulator. In this paper we explore in detail Google’s decision to phase out support for third-party cookies on Chrome, accompanied by a set of proposals known as the Privacy Sandbox proposals. We query whether this decision raises any antitrust concerns – and if so, how they can be reconciled with the objective of privacy. At a conceptual level, we use this opportunity to reflect on the relationship between competition law and privacy and the trade-offs regulators may have to make.