We document and then develop a model explaining and relating changes in firms'' organisation and in urban structure. Sharing of business services by headquarters and of sector-specific intermediates by production plants within a city reduces costs, while congestion increases with city size. A...

This paper explores the role of knowledge flows and TFP growth by using direct survey data on knowledge flows linked to firm-level TFP growth data. Our knowledge flow data correspond to the kind of information flows often argued, especially by policy-makers, as important, such as within the...