Under Johnston’s stewardship, the OECD took the global lead in establishing the Principles of Corporate Governance (now the world standard) and revised the Guidelines for Multinational Enterprises, the bedrock of what is now known as corporate social responsibility. The Organisation also championed the correction of international harmful tax practices and the international harmonization of competition policy, while at the same time fostering sustainable development, which Johnston introduced to the OECD shortly after his arrival. He also created the Education Directorate which introduced the Program of International Student Assessment (PISA), now the leading reference for international educational comparisons.