International linkages, local externalities, innovation and productivity. A structural model of Italian manufacturing firms

Using a large sample of Italian manufacturing firms, in this paper we estimate a structural model of research, innovation, productivity and export performance augmented to take account for the role played by local externalities. This model, which is an \u201cenlarged\u201d version of Crepon, Duguet and Mairesse (1998) model, comprises four main equations. The first identifies the factors underlying the intensity of Research and Development (R&D) investments; the second links R&D capital to innovation output; the third focuses on Total Factor Productivity (TFP) as determined by innovation; the fourth relates export performance to TFP. Our estimates show the significant role played by local externalities in these processes. In particular, related variety and urbanization positively affect the creation of new ideas through R&D, while specialization impacts on TFP to complement innovation output. Finally, urbanization economies support TFP in driving firms\u2019 export performance