This book deals with the theoretical and empirical questions of federalism in the context of five case studies: Austria, Belgium, Canada, Germany and Switzerland. The central argument is that in the long run the political institutions of federalism adapt to achieve congruence with the underlying social structure. This change could be in the centralist direction reflecting ethno-linguistic homogeneity, or in decentralist terms corresponding to ethno-linguistic heterogeneity. In this context, the volume: fills a gap in the comparative federalism literature by analyzing the patterns of change and continuity in five federal systems of the industrial west, this is done by an in-depth empirical examination of the case studies through a single framework of analysis illustrates the shortcomings of new-institutionalist approaches in explaining change, highlighting the usefulness of society-based approaches in studying change and continuity in comparative politics. Explaining Federalism will be of interest to students and scholars of federalism, comparative government, comparative institutional analysis and comparative public policy.