Firms are more productive on average in larger cities. Two explanations have been offered: agglomeration economies (larger cities promote interactions that increase productivity) and firm selection (larger cities toughen competition allowing only the most productive to survive). To distinguish...

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 firms and people in them, change over time? How does the sectoral composition of cities...

Firms are more productive on average in larger cities. Two explanations have been offered: agglomeration economies (larger cities promote interactions that increase productivity) and firm selection (larger cities toughen competition allowing only the most productive to survive). To distinguish...

Why do cities grow in population, surface area, and income per person? Which cities grow faster and why? To these questions, the urban growth literature has offered a variety of answers. Within an integrated framework, this chapter reviews key theories with implications for urban growth. It then...

Why do cities grow in population, surface area, and income per person? Which cities grow faster and why? To these questions, the urban growth literature has offered a variety of answers. Within an integrated framework, this chapter reviews key theories with implications for urban growth. It then...

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 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...

Why do cities grow in population, surface area, and income per person? Which cities grow faster and why? To these questions, the urban growth literature has offered a variety of answers. Within an integrated framework, this chapter reviews key theories with implications for urban growth. It then...