In the modern economy, algorithms influence many aspects of our lives, from how much we pay for groceries and what adverts we see, to the decisions taken by health professionals. As is true with all new technologies, algorithms bring new economic opportunities and make our lives easier, but they also bring new challenges. Indeed, many competition authorities have voiced their concerns that under certain circumstances algorithms may harm consumers, lead to exclusion of some competitors and may even enable firms (knowingly or otherwise) to avoid competitive pressure and collude. In this article, we explain how algorithms work and what potential benefits and harms they bring to competition.

Around the world, competition agencies and academics alike have raised concerns that the existing suite of policy tools and economic theory fail to capture all of the harms that can arise in digital markets. At the same time, other academics and practitioners consider that competition policy and industrial organization is unable to account for many of the benefits that online platforms and digital ecosystems can bring. As a range of new interventions – ranging from strengthened ex-post enforcement tools to new ex-ante regulations – are being proposed, we ask which view is right? Are the business practices observed in digital markets and targeted by these reforms so obviously harmful that they are deserving of a return to form-based prohibitions in place of effects-based analysis? Or does this represent an unhelpful regression, based on a misunderstanding of how these new types of markets function?