Policy Diffusion Speed: A Replication Study Using the State Policy Innovation and Diffusion Database

Data accumulation efforts are pushing the study of policy innovation diffusion in new directions. This replication study uses one such effort, the State Policy Innovation and Diffusion database, to interrogate the claim that policy attributes like salience and complexity condition the speed of innovation adoption. The study finds that policy complexity does push the effect of policy salience in a negative direction. However, it also finds substantial heterogeneity in these conditional effects across State Policy Innovation and Diffusion’s major constituent datasets. In addition, while not completely answering questions about convenience sampling bias, the study shows that the fundamental results do not change with one re-weighting of the results to capture a hypothetical distribution of the population of state policy innovations. The article concludes with future directions for the study of both policy diffusion within American federalism and cross-national diffusion.