We develop a simple Cournot type, two-stage competition model that reveals that firms tend to reduce their R&D investment more in denser locations than in lesser ones with the presence of knowledge spillover. This implies that local agglomeration increases the negative impact of knowledge...

We re-examine the long-run geographical development of U.S. manufacturing industries using recent advances in spatial concentration measures. We construct spatially-weighted indices of the geographical concentration of U.S. manufacturing industries during the period 1880 to 1997 using data from...