
Economic regulators make decisions in sectors such as energy, water, telecommunications and transportation that significantly affect citizens, businesses and the environment. The quality of their decisions depends on their ability to systematically assess potential impacts and consider the most effective approach for achieving regulatory objectives. Regulatory impact assessment (RIA) provides decision makers within regulatory authorities the necessary framework for conducting this analysis. This paper draws on the OECD's experience working with countries to develop and implement best practice principles for RIA. It presents a reference methodology and recommendations for national regulatory authorities to systematically adopt RIAs, reinforcing and complementing existing national efforts. The methodology integrates environmental and social impact criteria alongside economic criteria, and is tailored to sector regulators, accounting for their unique decision-making processes, mandates and regulatory challenges. The methodology provides regulators with a complete toolkit covering problem identification through to implementation. This project was supported by the European Union via the Technical Support Instrument.