ABSTRACT
Institutionalization is the principal concept used to compare party systems in new and old democracies, and it has given rise to a vibrant field of studies in comparative politics. In assessing the mechanisms of institutionalization, the main goal is to explore the different pathways of party system development. Environmental mechanisms refer to the external conditions within which party systems develop, whereas relational mechanisms concern political actors and their interpersonal networks. Environmental mechanisms derive from the mode of democratic transition and from the choices over political institutions. A quick glance at a sample of parliamentary elections recently held across sub-Saharan Africa immediately reveals the diversity in levels of party system institutionalization (PSI). A series of data sources are used to create operational indicators to test the major explanations of PSI: historical legacies, social structure, political institutions, party–citizen linkages and socio-economic development. The chapter also presents some of the key concepts discussed in this book.
