Institutional theory in political science : the new institutionalism Institutional theory plays a significant role in contemporary political science. As in the previous editions the new fourth edition provides an overview of the major institutional approaches in the discipline as well as considering the possibility of a more integrated institutional theory. This edition also contains two new chapters. One assesses the role of informal institutions and their linkages with formal structures of governing. The second new chapter provides a detailed discussion of the processes of institutionalization and deinstitutionalization.