We start this conceptual and theoretical chapter by recapitulating previous work on exclusion and civil war by outlining how it connects political exclusion and grievances with the onset of conflict. Consequently, if power sharing reduces inequality and exclusion, peace becomes more likely through a grievance-reducing effect. In addition, power sharing can also bring peace through confidence building. After defining the key notion of power sharing practices, we introduce our first Master Hypothesis about linking both governmental and territorial power-sharing practices to the reduction of civil conflict. The rest of the chapter advances four additional master hypotheses that correspond to the four initial challenges confronting research on power sharing and conflict that were introduced in Chapter 1. First, we derive Master Hypothesis 2 by arguing that practices channel the main conflict-reducing effect of formal power-sharing institutions and also reduce conflict even in the absence of formal institutions. According to Master Hypothesis 3, power-sharing practices have a pacifying effect both before and after the first conflict but the risk of conflict onset is generally higher in the latter case. With Master Hypothesis 4, we address the important issue of endogeneity by showing that governments introduce power-sharing arrangements mostly as a way to co-opt potentially violent challenges to their sovereign power. Finally, under the heading of Master Hypothesis 5, we show how territorial power sharing, especially in relationships already characterized by past violence, may be insufficient to build confidence in support of stable peace. In such cases, autonomy and other territorial approaches are more effective if combined with central power-sharing practices.

Given the huge number of writings covering power sharing in general, and its relationship to internal conflict in particular, it is essential to summarize what has been written in order to position the current work in this context. Thus, the first half of the chapter offers a straightforward overview of the relevant literatures. While this summary pays attention to conceptual issues and how the literature has analyzed the consequences of power sharing in broad terms, the primary focus is on conflict. Proceeding chronologically, the chapter starts with an account of the central divide in comparative politics between those perspectives that endorse power sharing, and those that oppose it. We retrace this classical divide back to the early writings of Lijphart, who introduced his consociational approach to stable democracy in divided societies in opposition to majoritarian democracy as practiced in Anglo-Saxon countries. The review of the literature covers its main stages together with work by other scholars working within this tradition as well as its main critics, including most prominently Horowitz, Rothchild and Roeder, and more recently research by Gates, Strøm and others. We then turn to the literature on post-conflict agreements. A section summarizing the main arguments for and against power sharing follows. The chapter ends with a discussion of the four challenges identified in Chapter 1.