To identify communication externalities in French cities, we exploit a unique survey recording workplace communication of individual workers. Our hypothesis is that in larger and/or more educated cities, workers should communicate more. In turn, more communication should have a positive effect...

Why are some cities specialised and others diversified? What are the advantages and disadvantages of urban specialisation and diversity? To what extent does the structure of cities, and the activities of the firms and people in them, change over time? How does the sectoral composition of cities...

We use a point-pattern methodology to explore the detailed location patterns of UK manufacturing industries. In particular, we consider the location of entrants and exiters vs. continuing establishments, domestic- vs. foreign-owned, large vs. small, and affiliated vs. independent. We also...

In this paper we introduce the concept of productive systems. Assuming a complementarity between skills and technology (more 'complex' technologies are intrinsically more productive but they require a more skilled labour force) and gains from the division of labor, firms face a trade-off between...

When firms cluster in the same local labor market, they face a trade-off between the benefits of labor pooling (i.e., access to workers whose knowledge help reduce costs) and the costs of labor poaching (i.e., loss of some key workers to competition and the indirect effect of a higher wage bill...

To study the detailed location patterns of industries, and particularly the tendency for industries to cluster relative to overall manufacturing, we develop distance-based tests of localisation. In contrast to previous studies, our approach allows us to assess the statistical significance of...

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...

A simple model of process innovation is proposed, where firms learn about their ideal production process by making prototypes. We build around this a dynamic general equilibrium model, and derive conditions under which diversified and specialised cities coexist. New products are developed in...

We study the impact of local taxation on the location and growth of firms. Our empirical methodology pairs establishments across jurisdictional boundaries to estimate the impact of taxation. Our approach improves on existing work as it corrects for unobserved establishment heterogeneity, for...

We consider the literatures on urban systems and New Economic Geography to examine questions concerning agglomeration and how areas respond to shocks to the economic environment. We first propose a diagrammatic framework to compare the two approaches. We then use this framework to study a number...