Aerospace Clusters: Local or Global Knowledge Spillovers?

The literature about regional innovation systems, clusters and industrial districts insists on the importance of local knowledge spillovers. Nevertheless, more recently a few authors have put in question the importance of local knowledge spillovers. This paper provides an analysis of some of the most dynamic aerospace clusters in the world, located in Montreal, Seattle, Toulouse and Toronto. We start by discussing theories of clustering, then provide research questions as well as empirical evidence on the international nature of knowledge spillovers. Local knowledge spillovers are less significant, of a different nature, and they may make a scanty contribution to explain the geographical agglomeration of firms. Conversely, international spillovers help to explain the relative dispersion of industry across nations. Resilient geographical clustering is related to the anchor tenant effects as creators of labour pools and owners of very large manufacturing plants creating regional inertia. We thus reject the local knowledge spillover explanation of aerospace clusters in favour of another one based on anchor firms and their effects on the local labour pool.