After a decade of academic and policy-making debate surrounding cluster development theory and practice – accelerated if not necessarily launched by Michael Porter's work – the terms of inquiry have begun to shift. With respect to cluster policy – that set of public sector interventions designed to influence cluster development – attention is moving away from simple reporting and description of cluster policy activity to more intensive investigations, if not challenges, about its substance. The existence of cluster policy is not in itself controversial – over the last decade, there has been a global proliferation of self-styled 'cluster' policies. The terminology of cluster development has informed economic, sectoral and spatial development policies at national, regional and local levels. The use of the analytical tools associated with cluster policy is not only widespread in Western Europe and North America (Roelandt and den Hertog, 1999), but increasingly in less-developed parts of the world as well (Schmitz and Nadvi, 1999). As a coherent policy approach, it has been promoted by international development organisations, such as the European Commission, OECD and UNIDO, and led to the formation of policy-maker associations interested in pursuing cluster development, such as the Competitiveness Institute.