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...

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...

London is one of the world’s major cities, and one of its most diverse. London’s cultural diversity is widely seen as a social asset, but there is little hard evidence on its importance for the city’s businesses. Theory and evidence suggest various links between urban cultural diversity...

Spatial inequality in developing countries is due to the natural advantages of some regions relative to others and to the presence of agglomeration forces, leading to clustering of activity. This paper reviews and develops some simple models that capture these first and second nature economic...

High levels of net migration to the UK have contributed to growing cultural diversity, and researchers are turning their attention to the long-term effects of diversity on productivity. Yet little is known about these issues. This paper asks: what are the links between the composition of firms'...

Ethnic inventors play important roles in US innovation systems, especially in high-tech regions like Silicon Valley. Do ‘ethnicity-innovation’ channels exist elsewhere? This paper investigates, using a new panel of UK patents microdata. In theory, ethnicity might affect positively innovation...

The digital industries cluster known as 'Silicon Roundabout' has been quietly growing in East London since the 1990s. Now rebranded 'Tech City', it is now the focus of huge public and government attention. National and local policymakers wish to accelerate the local area's development: such...

In recent years, the economics of migration literature has shown a substantial growth in papers exploring host country impacts beyond the labour market. Specifically, researchers have begun to shift their attention from labour market and fiscal changes, towards exploring what we might call...

This paper is concerned with the urban wage premium and addresses two central issues about which the field has not yet reached a consensus. First, the extent to which sorting of high ability individuals into urban areas explains the urban wage premium. Second, whether workers receive this wage...