This paper investigates whether localization economies as brought forward by Marshall (1890) or urbanization economies as mentioned by Jacobs (1970) are more decisive for regional gross value added per capita. Our novel approach is to explicitly allow for interdependencies between these two...

We extend the agglomeration economies literature (1) by comparing the effects on productivity of geographic concentrations in IT activity and all other activity and (2) by distinguishing between the effects of IT-producing and IT-using sectors on productivity. Four measures of agglomeration for...