On Waves, Clusters, and Diffusion : A Conceptual Framework

This article makes a conceptual and theoretical contribution to the study of clustered political and economic reforms. Conceptually, we review the use and meaning of the concept of diffusion as well as its related terms. We suggest that the concept be reserved for processes (not outcomes) characterized by a certain uncoordinated interdependence. Theoretically, we identify the principal sources of clustered policy reforms. We then clarify the characteristics specific to diffusion mechanisms and introduce a categorization of such processes. In particular, we make a distinction between two types of diffusion: adaptation and learning. We argue that this categorization adds conceptual clarity and distinguishes mechanisms with distinct substantive consequences