Institutional theory has long focused attention on the organizing capacities of society, to the relative neglect of standard conceptions of actors, interests and power. Indeed, in sociological institutionalism, actors, interests and, to a large extent, power, are regarded, for analytical purposes, as deriving from institutions and culture. By focussing upon the broad institutional frameworks of society and breaking with rational actor models, institutional theory purposely defocalizes ?actors?. In fact, the opportunities for institutionalist conceptions of actors, interests and power are little developed in contemporary institutional theories of organization and organizing. However, being rooted in sociological traditions such as the sociology of knowledge or ethnomethodology, action and power are not residual but core concepts of institutionalism. Most empirical and/or conceptual studies in the tradition of institutional theory pay tribute to this heritage, at least implicitly, and refer to interests, agency and power in order to explain changes in institutional structures, for example, in the emergence of new institutions, institutionalized structural elements and management practices. In this sub-theme, we will connect to this research, while explicitly calling attention to the fundamental assumptions of sociological institutionalism. Thus, the challenge is to re-integrate agency, interests and power, but to remain distinctively institutional and avoid turning institutionalism into a modified actor/interest/power theory. In the spirit of previous EGOS colloquia, this sub-theme track will provide a forum to keep up the dialogue which is developing between the variety of strands of institutionalism in the European and North American traditions. We invite papers for this sub-theme that ? explore empirically the role and relevance of actors, interests and power, for example in processes of institutional change and stability, or the creation of new institutions, or in intra- and inter-institutional dynamics, ? conceptually and/or methodologically advance avenues for integrating actors, interest and power in ways that resonate with the basic perspective of sociological institutionalism, ? reject conceptually and/or empirically the argument that actors, interests and power need to be integrated into institutional theory, and address ways in which the criticisms on institutional theory can be countered, ? focus and specify new directions for institutionalism as a theoretical research program that engages with relevant social and cultural theory about actors, interests, and power. Sub-theme format The sub-theme wishes to attract both high-quality contributions that are ready for research journal submission as well as research in progress. It seeks to provide an opportunity for engaging in constructive dialogue and to encourage mutual learning among the participating scholars. Papers will be distributed in advance of the Colloquium. Session leaders will be asked to provide insights for discussion that cut across and beyond the various papers in their session. In order to allow for as much discussion as possible among the participating scholars, paper presentations will be restricted to brief summaries of the research?s highlights. About the Convenors: Renate Meyer is Associate Professor at the Department of Public Management (Wirtschaftsuniversität Vienna) where she received her Habilitation in 2003. She was a co-convenor of sub-theme 40 (?Changing institutions, instituting change: Heterogeneity in institutional theories of organizations?) in 2004. Her research interests are the transformation of institutional logics and the diffusion of management concepts with a current focus on the public sector. Kerstin Sahlin-Andersson is Professor in Management at Uppsala University. She has published books and articles on the global circulation of management models and standards, organizational changes in public sector, transnational regulations, and the organizing of large projects. Her current research interests form around the three research programs: ?Transnational regulations and state transformations?, ?Corporate social responsibility and changes in public - private relations?, and ?The Strive for Transparency in Health Care?. Marc Ventresca is University Lecturer in Strategy at the Saïd Business School, University of Oxford, and Fellow Wolfson College. He was a co-convenor of EGOS sub-theme 40 (?Changing institutions, instituting change: Heterogeneity in institutional theories of organizations?) in 2004. His research interests are in industry dynamics, institutions, and entrepreneurial activity and in the transnational diffusion of policy reforms and strategies. Peter Walgenbach is Professor of Organization Theory and Management at the University of Erfurt, Germany. He received his PhD and his Habilitation at the University of Mannheim, Germany. He was a visiting scholar at Stanford University, CA in 1997 and 2001. His research interests are in institutional theory, structuration theory, international comparative research and the diffusion and application of popular management concepts.