Elkins, ZacharySimmons, Beth2010-02-112005Elkins, Zachary, and Beth Simmons. 2005. On waves, clusters, and diffusion: A conceptual framework. The Annals of the American Academy of Political and Social Science 598(1): 33-51.0002-7162http://nrs.harvard.edu/urn-3:HUL.InstRepos:3630582This article makes a conceptual and theoretical contribution to the study of diffusion. The authors suggest that the concept of diffusion be reserved for processes (not outcomes) characterized by a certain uncoordinated interdependence. Theoretically, the authors identify the principal sources of clustered policy reforms. They then clarify the characteristics specific to diffusion mechanisms and introduce a categorization of such processes. In particular, they make a distinction between two types of diffusion: adaptation and learning. They argue that this categorization adds conceptual clarity and distinguishes mechanisms with distinct substantive consequences.en-USdiffusionclusteringconvergencepolicy reformadaptationlearningcontagionJournal Article10.1177/0002716204272516