https://macropaperwarehouse.com/authors/woojin-kim/Woojin KimHugo -- gohugo.ioen-ushttps://macropaperwarehouse.com/papers/policy-diffusion-and-polarization-across-u.s.-states/https://macropaperwarehouse.com/papers/policy-diffusion-and-polarization-across-u.s.-states/<p>DellaVigna and Kim study the innovation and diffusion of policies across U.S. states using a dataset of over 700 state laws spanning seven decades. The central question is what predicts whether a state adopts a policy — and how those predictors have changed over time. The paper draws on two primary data sources: the State Policy Innovation and Diffusion (SPID) Database (Boehmke et al., 2020), covering 676 policies, and a hand-collected sample of 57 policies from 91 NBER working papers (April 2012–September 2021) that feature state-level policy variation. The combined dataset covers 733 policies adopted from the 1950s onward across the contiguous 48 states.</p>