Striking evidence is presented of a previously unremarked transformation of urban structure from mainly sectoral to mainly functional specialisation. We offer an explanation showing that this transformation is inextricably interrelated with changes in firms' organisation. A greater variety of...

This handbook chapter 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...

There is controversy about whether geography matters mainly because of its contemporaneous impact on economic outcomes or because of its interaction with historical events. Looking at terrain ruggedness, we are able to estimate the importance of these two channels. Because rugged terrain hinders...

Increasingly, a small number of low-wage countries such as China and India are involved in innovation -- not `big ideas' innovation, but the constant incremental innovations needed to stay ahead in business. We provide some evidence of this new phenomenon and develop a model in which there is a...

The incremental innovations that underly much of modern economic growth typically involve changes to one or more components of a complex product. This creates a tension. On the one hand, a principal would like an agent to contribute innovative components. On the other hand, ironing out...

International trade can have profound effects on domestic institutions. We examine this proposition in the context of medieval Venice circa 800-1350. We show that (initially exogenous) increases in long-distance trade enriched a large group of merchants and these merchants used their new-found...

We investigate the relationship between interstate highways and highway vehicle kilometers traveled (VKT) in US cities. We find that VKT increases proportionately to highways and identify three important sources for this extra VKT: an increase in driving by current residents; an increase in...

This paper examines the effects of urbanization on development and growth. It begins with a labor market perspective and emphasizes the importance of agglomeration economies, both static and dynamic. It then argues that more productive jobs in cities do not exist in a void and underscores the...

Growing research and policy interest focuses on the misallocation of output and factors of production in developing economies. This paper considers the possible misallocation of financial loans. Using plant-level data on the organized and unorganized sectors, the paper describes the temporal,...