Policy Diffusion Dynamics in America integrates research from agenda setting and epidemiology to model factors that shape the speed and scope of public policy diffusion. Drawing on a data set of more than 130 policy innovations, the research demonstrates that the 'laboratories of democracy' metaphor for incremental policy evaluation and emulation is insufficient to capture the dynamic process of policy diffusion in America. A significant subset of innovations trigger outbreaks - the extremely rapid adoption of innovation across states. The book demonstrates how variation in the characteristics of policies, the political and institutional traits of states, and differences among interest group carriers interact to produce distinct patterns of policy diffusion.

“It is hard to innovate in a literature as well established as that on policy diffusion. But here we have something really new: an interdisciplinary theoretical foundation, an exhaustive empirical scope covering over 100 new policies and more than 100 years, and findings that will surprise. Like a disease, new policies can suddenly emerge after long periods of incubation. Many of the concepts related to the epidemiological study of how diseases spread (or are contained) prove to help us understand how new policy ideas sometimes find no foothold but occasionally break out in a nation-wide stampede. The country may be better or worse off for these new ideas, but students of public policy, state government, and policy dynamics will all want to be familiar with this path-breaking new book.”
—Frank R. Baumgartner, University of North Carolina, Chapel Hill

“Graeme Boushey shows us that policy diffusion processes are often characterized by ‘policy outbreaks’ of rapid mimicking, not solely the simple incremental, deliberate mechanism of ‘laboratories of democracy’ lore. Unlike the trial-and-error process of incremental learning, policy outbreaks are not at all reassuring; they are disruptive and potentially sub-optimal. Boushey demonstrates with a new dataset on policy adoptions in the states that such outbreaks occur (along with the standard incremental adoptions), and proposes a new approach based on epidemiological models of the spread of disease. This is a critically important and potentially path-breaking book.”
—Bryan Jones, University of Texas, Austin

“With its innovative theoretical framework and impressive empirical scope, Policy Diffusion Dynamics in America sheds new light on the complex political process through which ideas and policies spread from state to state. It asks the big, important questions that are sometimes neglected in contemporary diffusion research, and its well-executed and wide-ranging comparative analysis boldly challenges conventional portrayals of the diffusion process. This is an important book that will have a major impact on future scholarship.”
—Andrew Karch, University of Minnesota

“This is a path-breaking study that advances both theory and research in policy diffusion, and will be cited extensively for its contributions. One of the dilemmas of diffusion research has been how to develop more generalizable theory beyond studies of discrete policy innovations. Boushey examines a wide variety of policy issues, but he does much more in building theory, identifying distinct patterns across policy types and firmly embedding them in more general theories of agenda-setting and policy change. This book will change our thinking and research on policy diffusion.”
—Karen Mossberger, University of Illinois at Chicago

“Combining theories of punctuated equilibrium and policy diffusion, Graeme Boushey creates a compelling new account of policymaking in American federalism. The nature of the policies themselves, their targets, and their advocates dictate the dynamics by which innovative policy spread across the states. Boushey’s focus on the speed and scope of diffusion will guide scholars of American and comparative politics, as well as those outside of political science.”
—Craig Volden, The Ohio State University