A rich body of literature has emerged that introduces concepts for describing and analysing the making of policies that span across different policy sectors such as energy and environmental policy. Some of the most prominent concepts in the literature are “policy integration”, “boundary-spanning policy regimes”, “horizontal governance or government”, and “joined-up government” – just to name but a few. In this paper we systematically review these concepts in order to pursue two analytical goals. First, we want to assess the extent to which these different concepts relate to the same empirical phenomenon. Second, we aim to carve out the analytical implications of these different concepts for studying the vertical relations of policy sectors. We seek to explore, for example, whether studies on “policy integration” pay more attention to conflicts among the sector-specific actors as compared to – let us say – research on “horizontal governance”. By pursuing these two goals, we ultimately aim to put forward a classification of the concepts that helps to highlight to what extent they relate to comparable empirical phenomena, and which analytical insights the individual concepts of policy coordination can produce. We believe that such a descriptive assessment of the literature is a necessary first step to bring together the different conceptual and theoretical components of cross-sectoral policy coordination that exist in mostly isolate strands of research. In this way, our paper can serve as a point of departure for (comparative) empirical analysis.
