Industrial Clusters: Complexes, Agglomeration and/or Social Networks?

The concept of industrial clusters has attracted much attention during the past decade, both as descriptive of an increasingly important phenomenon and as a basis for effective public intervention in the economies of lagging city-regions. However, there is much ambiguity in the way in which this concept is used, presenting an obstacle both to empirical testing and to realistic assessments of policy relevance. In this paper, we distinguish three ideal-typical models of processes which may underlie spatial concentrations of related activities, with very different implications both in terms of relevant evidence and the scope for promotional policies. Survey data for the London conurbation are used to explore the relation between concentration and different forms of linkage, with results which point to the dominance of pure agglomeration effects in this context at least.