International organizations (IOs) have limited formal control over private actors such as business corporations. As corporate behaviour is increasingly consequential for the goals of IOs, there is a growing interest in alternative institutions of ‘global governance’. Defi ned as ‘systems of rule at all levels of human activity – from the family to the IO – in which the pursuit of goals through the exercise of control has transnational repercussions’ (Rosenau 1995: 13), global governance implies an active role for corporations (Ronit and Schneider 1999). Voluntary codes and other private initiatives are major vehicles to engage business corporations and their perceived social responsibilities. Over the past two decades, such initiatives have developed into central pillars of global governance, as IOs are increasingly encouraging and orchestrating such schemes in their efforts to share the task of global governance with private actors. While these schemes are intended to encourage ethical practices by participating corporations that go beyond compliance with existing rules and regulations, assessing their success depends on a thorough understanding of the extent to which corporations participate and why, as well as of the differences these programmes can be expected to make for goals such as sustainable development and the safeguarding of human and labour rights.