This chapter traces how the concern about negative economic liberty encoded in the consumer welfare standard and the laissez-faire antitrust approach coined by the Chicago School have transformed competition law on both sides of the Atlantic. It shows how this shift from republican to negative liberty as normative bedrock of competition law led to a recalibration of the role of legal presumptions, the standard of harm and the error–cost framework. It thus identifies the main parameters that drove the transformation of US and EU competition law from a republican antirust to a laissez-faire antitrust approach. This transfiguration displaced republican liberty as non-domination by a thinned-out understanding of negative liberty as non-interference as the ultimate goal of modern competition law and led to the disappearance of the idea of a competition–democracy nexus.

This chapter analyses the decline of the concern about liberty as non-domination and the idea of a competition–democracy nexus following the ascent of the Chicago School and the rise of a More Economic Approach towards antitrust law on both sides of the Atlantic. It shows how the Chicago School not only challenged the economic foundations of the republican antitrust tradition but also put forward the consumer welfare standard as a versatile, principled framework to supersede the conception of republican liberty with a narrow negative notion of economic liberty as non-interference. The Chicago School thus shaped a laissez-faire approach to antitrust that seeks, in the first place, to preserve entrepreneurial liberty against state interference.