The analysis of the previous chapter has mostly confirmed the key arguments advanced by this book. Decision rules, policy complexity, conflict between the Commission and the pivotal government, and within the Council are systematically related to the choices of delegation and discretion taken by EU legislators. However, estimates and inferences of quantitative models are only as good as our conceptualization, measurement, data sources and statistical estimation techniques. However careful we could be, each of these steps could be fraught with problems and implicit assumptions, and establishing association among variables is not quite the same as establishing causality. Does majority voting facilitate delegation to and greater discretion of the Commission? Does it lead to more constrained national implementation? Does intense conflict within the Council, mediating with majority voting, also generate these outcomes? Do the bureaucratic capabilities of the Commission and of national administrators guide these decisions? Does the Council confer less authority to a Commission with divergent preferences?

This chapter seeks to address these questions. It relies on case-oriented qualitative evidence to unveil causal mechanisms and to provide analytical depth to the quantitative analysis of Chapter 5. The chapter includes a detailed examination of the processes of delegation over a period of time across four policy areas: public procurement, fisheries, internal market and taxation. Respectively, the cases cover in detail the legislation regulating the procedures for the award of public contracts, the measures for the management and conservation of fisheries resources, the acts liberalizing and regulating the market for telecommunication services and a directive on the taxation of savings income.