Relatedness as driver of regional diversification: a research agenda. Regional Studies. The regional diversification literature claims that regions diversify in new activities related to their existing activities from which new activities draw on and combine local capabilities. The paper offers a critical assessment and identifies a number of crucial issues for future research. It calls for (1) a disentanglement of the various types of capabilities that make regions diversify; (2) the inclusion of more geographical wisdom in the study of regional diversification, like a focus on the effects of territory-specific contexts, such as institutions; (3) a thorough investigation in the conditioning factors of related and unrelated diversification in regions; and (4) a micro-perspective on regional diversification that assesses the role of economic and institutional agents in a multi-scalar perspective.