Young highly educated workers developed in the 70 s and 80 s a preference for working in larger cities. As a consequence highly educated young workers in 1990 were over-represented in cities, in spite of the lower wage premium they earned for working in crowded metropolitan areas if compared to...

The diffusion of knowledge in the world generates positive externalities if knowledge flows increase the productivity of R&D. Our work analyzes knowledge diffusion and knowledge externalities in generating innovation and in determining productivity. We first estimate the determinants of...