On Clustering in the Location of R&D: Statics and Dynamics

Empirical analyses of research and development find strong evidence that these activities tend to cluster geographically. Clusters are thought to emerge from the presence of localized positive externalities. This paper presents a model of this clustering behaviour. We find that phase changes in clustering exist both as the strength of local externalities changes and as the degree of heterogeneity among firms changes. The dynamics of the system are examined as it responds to shocks to the size of the market for R&D output, and the length scale of the spatially dependent externalities. Dynamic responses take place in two distinct stages: a rapid response to the change in market systems which takes place throughout the space, with litlle regard to externality effects; followed by a slow re-agglomeration process as producers change their spatial decisions to lower the costs of the new production level.