Abstract

This study develops and tests the Petroleum Regulatory Index (PRI) as a comparative framework for assessing petroleum regulatory maturity across East African Community member states. The Petroleum Regulatory Index (PRI) is the first composite, legally grounded indicator for evaluating petroleum sector governance. Developed for use within the East African Community (EAC), the PRI provides a systematic framework for assessing regulatory maturity. The PRI employs a three-pillar framework comprising the Regulatory Governance Index (RGI) for governance evaluation, the Regulatory Substance Index (RSI) for assessing regulatory instruments, and the Regulatory Outcome Index (ROI) for quantifying sectoral performance. By integrating doctrinal legal analysis with quantitative data, the PRI allows evidence-based evaluation of institutional autonomy, accountability, transparency, and regulatory performance. It includes indicator selection, data sourcing, and validation to ensure empirical rigour. Methodologically, this study advances regulatory measurement by incorporating legal verifiability criteria into the construction of composite indicators. This links normative legal scholarship with empirical governance evaluation. The analysis identifies legal autonomy, fiscal capacity, and stakeholder participation as key determinants of regulatory effectiveness. The findings show clear variation across the EAC, with stronger performance where statutes provide clearer mandates, greater autonomy, and stronger disclosure obligations. Other jurisdictions remain in the early stages of institutional development. Policy recommendations include regional harmonisation of petroleum legislation, institutional capacity building, and digital transparency reforms. The PRI provides a replicable and adaptable model for evidence-based governance reform in petroleum sectors. It contributes to the broader discourse on regulatory convergence and sustainable energy governance in Africa.