In a phrase coined by Lord Bryce and popularized by Justice Louis Brandeis, America 's separate states are seen as "laboratories of democracy," giving the United States fifty channels for generating fresh new approaches to public problems. The potential advantages are apparent. But how fully this potential is realized depends on how rapidly and reliably innovations developed in each "laboratory" diffuse to other states. The literature on the diffusion of innovations is limited, and rather stale. The archives of the Innovations in American Government offer a promising but mostly untapped data set for exploring the replication of valuable innovations. Alan Gerber of Yale and Eric Patashnik of Virginia asked John D. Donahue to write a paper that exploits the history of Innovations to test alternative hypotheses about the diffusion of state-level innovations, for a major conference and book project on "American Democracy and the Political Economy of Government Performance." A research award from the Ash Institute has made it possible for him and a team of research assistants to identify state-level award winners and begin work this summer to trace the pace and pattern of their diffusion. This paper was produced as the result of a research competition open to faculty of the John F. Kennedy School of Government sponsored by the Ash Institute of Democratic Governance and Innovation.