This chapter claims that the operation and success of a leniency programme are premised on a carrot-and-stick approach that is expected to lead to a race for confession, as the highest and sometimes only reward – depending on the design of the leniency programme – is for the first cartel member to defect and cooperate with the authorities. The main pre-requisites to instigate this race for confession are the threat of severe sanctions if a cartel is caught, a high risk of detection of a cartel, and a high degree of transparency and predictability in relation to leniency. The chapter then argues that the early leniency programmes of the United States and the European Union have been revised with these pre-requisites in mind. To illustrate the importance of the theory, this chapter than evaluates the most recent version of the respective leniency programmes. The chapter finishes with some thoughts on the similarities and differences between the two leniency programmes.