Institutionalism has become one of the dominant strands of theory within contemporary political science. Beginning with the challenge to behavioural and rational choice theory issued by March and Olsen, institutional analysis has developed into an important alternative to more individualistic approaches to theory and analysis. This body of theory has developed in a number of ways, and perhaps the most commonly applied version in political science is historical institutionalism that stresses the importance of path dependency in shaping institutional behaviour.The fundamental question addressed in this book is whether institutionalism is useful for the various sub-disciplines within political science to which it has been applied, and to what extent the assumptions inherent to institutional analysis can be useful for understanding the range of behaviour of individuals and structures in the public sector. The volume will also examine the relative utility of different forms of institutionalism within the various sub-disciplines.The book consists of a set of strong essays by noted international scholars from a range of sub-disciplines within the field of political science, each analysing their area of research from an institutionalist perspective and assessing what contributions this form of theorising has made, and can make, to that research. The result is a balanced and nuanced account of the role of institutions in contemporary political science, and a set of suggestions for the further development of institutional theory.