This edition examines how randomised experiments can be used to inform economic policy in the Nordic countries. Drawing on experiences from large‑scale trials in areas such as taxation, labour markets, education, and social policy, the articles focus not only on what experiments reveal, but on how they are designed, authorised, and implemented in practice. The volume discusses concrete challenges faced by policymakers, researchers, and public authorities, including legal and ethical constraints, institutional cooperation, take‑up, data access, and spillover effects, and shows how these can be addressed in real‑world settings. Together, the articles offer practical guidance on how experimentation can be integrated into policy design to support more robust, evidence‑informed economic policymaking in the Nordic region.