Competition law and the regulation of excessive prices have a notoriously uneasy relationship. If competition authorities directly intervene in markets in order to secure lower prices they pursue a popular aim: fighting against monopoly profits is apparently a just and noble cause. However, there is a distinct feeling among many observers that by taking from the rich and giving to the poor, competition law enforcers gain popularity for all the wrong reasons: price interventions are based on the premise that authorities or courts are better than markets at detecting and bringing down monopoly rents. These interventions do not support the competitive process but change its outcome, and by doing so, they appear to threaten rather than to enhance the welfaregenerating potential of competition. Against this background, the abstention of US antitrust law with regard to the charging of monopoly prices seems to be self-evident, while the European approach of prohibiting the imposition of unfair prices by dominant undertakings, as most prominently featured in Article 102(2)(a) TFEU, but also in the competition laws of EU Member States such as Germany, begs for explanation. This chapter starts from the assumption that a deeper understanding of this peculiar divergence between US and European competition laws can only be found if a broad perspective is taken that includes the interplay between competition law and economic regulation. First, on a level of a positive comparative analysis (which will be the subject of section 2 of this chapter), the...