ABSTRACT
This chapter focuses on two topics: the analysis of the dependent variable and the crafting of the research framework. The chapter starts with an overview of the existing studies on party leader selection rules. It then discusses the limitations of some approaches and subsequently proposes the operationalisation of the dependent variable: the party leader selectorate. Afterwards, the case selection is analysed from a temporal and spatial viewpoint using a careful combination of existing data and new information on more than 50 parties in ten Western European countries in around 30 years. Furthermore, the chapter also asks the research question: why do parties open their leader selection rules? Following the operationalisation of the dependent variable, the question can be reformulated as follows: why do parties open their leader selectorate? Finally, the chapter discusses the research framework by distinguishing between intra-party and external factors, related to the party change framework and the personalisation of politics.
