“…Over decades, seeking deep insights into why some government entities adopt new policy ideas while others have not, has been a significant theme of public policy research (e.g., Berry & Berry, ; Easterly, ; Jensen, ; Mintrom, ). Empirical work in this train has generated a wealth of insights into why and how policy innovation takes place, with learning, imitation, normative pressure, competition, and coercion identified as five potential forces contributing to policy diffusion (Berry & Berry, ; Dobbin, Simmons, & Garrett, ; Shipan & Volden, ).…”