Climate Policy in the State Laboratory

This report by the World Resources Institute examines how state-level climate policy innovation in the United States can influence federal regulation, a process termed "vertical diffusion." By analyzing thirteen cases of policy diffusion and specific initiatives like the Regional Greenhouse Gas Initiative (RGGI) and California vehicle emissions standards, the report identifies key drivers that encourage the federal government to adopt state-led climate policies.

• The most critical drivers for the federal adoption of state policies (vertical diffusion) are the advocacy of state champions and the presence of spillover effects. While policy learning is also important, the availability of cost data does not appear to be a significant factor in the process.
• States can increase the likelihood of federal adoption by investing in communications programs for experts to provide testimony, disseminating program data and modeling results, and designing policies that encourage interstate cooperation and multi-state collective action.
• Early implementation of state policies provides a strategic advantage, as the lessons learned from these early actions are more likely to shape the eventual federal outcome than vice versa.
• While business support is not always critical for vertical diffusion, it remains helpful. The report suggests states should convene business coalitions that share policy goals to help endorse or design these policies.

APA

Lash, J. (n.d.). Climate Policy in the State Laboratory. World Resources Institute. https://www.wri.org/research/climate-policy-state-laboratory

Chicago

Lash, Jonathan. Climate Policy in the State Laboratory. World Resources Institute, n.d. https://www.wri.org/research/climate-policy-state-laboratory.

Wikipedia

{{cite report |last1=Lash |first1=Jonathan |title=Climate Policy in the State Laboratory |publisher=World Resources Institute |url=https://www.wri.org/research/climate-policy-state-laboratory |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{lashndclimate, author = {Lash, Jonathan}, title = {{Climate Policy in the State Laboratory}}, institution = {World Resources Institute}, url = {https://www.wri.org/research/climate-policy-state-laboratory}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }