The world has never been more interconnected. We can see this in international trade and investment flows, the movements of people, the economic activity of multinationals, and the internationalisation of research and development. However, while globalisation has seen unprecedented growth since the early 1990s, the world has not become “flat”. The growing fragmentation of production across borders identified in the OECD work on global value chains is matched by a fragmentation of norms and rules. Sometimes, it is for good reasons: specific rules and norms cater for specific needs and preferences or have historical roots and would bring little benefits to change. But most often divergences threaten co-ordinated policy action, hamper interoperability and raise unnecessary costs for citizens and businesses. The global financial and economic crisis has provided ample illustration of the dramatic impact of poor articulation and inadequate enforcement of rules across borders and reminded us of the pressing need for effective co-operation to address global systemic challenges.