ABSTRACT
The expansive scholarly literature on innovation and diffusion reaches across numerous disciplines and virtually every subfield of political science. This chapter provides a brief overview of the quantitative methods and discusses their respective strengths and limitations. It describes inferred network analysis, a relatively new approach to studying the diffusion process. The chapter focuses on the methodological implications of recent conceptual innovations in the study of policy diffusion. It examines forces that operate in multiple jurisdictions and transport innovations from one site to another. These “innovation vectors” may be responsible for the interdependencies that represent a diffusion episode. The chapter highlights a long-standing limitation of policy diffusion research, namely, its focus on the adoption decision. It concludes by identifying several avenues for future research that will help this expansive scholarly literature maintain its forward momentum.
