How much of the geographic clustering of economic activity is attributable to agglomeration spillovers as opposed to natural advantages? I present evidence on this question using data on the long-run effects of large scale hydroelectric dams built in the U.S. over the 20th century, obtained...

This paper proposes a model of urban agglomeration in conjunction with imperfect competition and endogenous product R&D of firms. The quality of differentiated manufacturing goods is a result of R&D services provided by research firms. Sectoral interactions are subject to spatially dependent...