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...

This Paper studies the theoretical micro-foundations of urban agglomeration economies. We distinguish three types of micro-foundations, based on sharing, matching, and learning mechanisms. For each of these three categories, we develop one or more core models in detail and discuss the literature...

The size distribution of cities in many countries follows some broadly regular patterns. Any good theory of city size distributions should (i) be able to account for this regularity, but also (ii) rely on a plausible economic mechanism and (iii) be consistent with other fundamental features of...

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

This paper reviews the evidence about the effects of urbanisation and cities on productivity and economic growth in developing countries using a consistent theoretical framework. Just like in developed economies, there is strong evidence that cities in developing countries bolster productive...

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...

We estimate the effects of major roads and public transit on the growth of major cities in the US between 1980 and 2000. We find that a 10% increase in a city’s stock of roads causes about a 2% increase in its population and employment and a small decrease in its share of poor households over...

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...

Why are some cities specialized and others diversified? What are the advantages and disadvantages of urban specialization 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...

We predict the amount, share, and value of land dedicated to roadways within and across 316 US Primary Metropolitan Statistical Areas. Despite the amount and value of land dedicated to roadway, our study provides the first such estimate across a broad range of metropolitan areas. Our basic...