When Is the Right Time to Do a Policy Diffusion Study?

2025/12/02 by Daniel J. Mallinson, Joshua M. Jansa · 1 voice
Environmental Science · Social Sciences · #Policy Transfer and Learning #Regional Development and Policy #Sustainability and Climate Change Governance

paper · pdf · doi:10.1017/spq.2025.10012

openalex created_date 2025/12/02 · openalex publication_date 2025/12/02 · openalex updated_date 2026/05/21

Abstract

Abstract Event history analysis (EHA) revolutionized the study of policy diffusion. However, many diffusion studies are snapshots of a policy’s spread. This begs the question of what we are learning from studies of (often) incomplete diffusion. The simple question that we ask – when should a diffusion study be conducted? – is complex to answer. We offer insight into this question using literature on EHA and empirical observation. We use data from the State Innovation and Policy Diffusion database on 83 policies that were adopted by at least 42 states to demonstrate how key results change as the observation window changes. We conclude with advice on how to approach modeling and interpreting incomplete policy diffusion in the future.

Citations

• State Lottery Adoptions as Policy Innovations: An Event History Analysis
• The Diffusion of Policy Diffusion Research in Political Science
• The Politics of Diffusion: Public Policy in the American States
• Who Are Your Neighbors? The Role of Ideology and Decline of Geographic Proximity in the Diffusion of Policy Innovations
• Salience, Scientific Uncertainty, and the Agenda‐Setting Power of Science
• Policy Innovation Adoption Across the Diffusion Life Course
• Growth and gaps: a meta-review of policy diffusion studies in the American states
• Theories Of The Policy Process
• Policy Learning and the Diffusion of Autonomous Vehicle Policy in the American States
• Promoting Reproducibility and Replicability in Political Science
• Back to the Future: Modeling Time Dependence in Binary Data

Discussions

• Very pleased to see this out and grateful to Josh for helping to take this from idea to a published article. It's intended to push diffusion researchers to think more about the context of the policy t [bsky, 1 points, 0 comments]

Related

• The Diffusion of Policy Diffusion Research in Political Science
• The Politics of Diffusion: Public Policy in the American States
• Growth and gaps: a meta-review of policy diffusion studies in the American states
• Policy Diffusion: The Issue‐Definition Stage
• Policy Innovation Adoption Across the Diffusion Life Course