Knowledge Spillovers and the Growth of Local Industries

The literature on localized knowledge spillovers and growth focuses on the relative importance of intra vs. inte r-industry externalities, but the nature and the characteristics of the dynamic linkages across manufacturing sectors are not investigated. In this paper we perform a very disaggregated analysis in order to identify, for each 3-digit industry, which composition of industrial activity is more conducive to growth. We find that diversity matters for growth, but each industry needs its own diversity. We provide some evidence of clustering of industries based on dynamic externalities. We find that many spillovers occur within input-output relationships. They often originate in downstream sectors favoring the growth of upstream industries. Lastly, the importance of spillovers does not depend on the technological intensity of the industry.