The geographic concentration of economic activity occurs because transport costs for goods, people and ideas give individuals and organisations incentives to locate close to each other. Historically, all of these costs have been falling. Such changes could lead us to predict the death of...

"This paper examines the effects of information and communication technologies (ICT) on urban structure. Improvements in ICT may lead to changes in urban structure, for example, because they reduce the costs of communicating ideas from a distance. Hence, they may weaken local agglomeration...

The government wants 3m houses built by 2020. Economic theory tells us their locations matter for living standards. Economics cannot tell us the optimal locations, but does show that houses are usually socially more valuable in high land-price areas, because additional workers are more...

The trend toward ever greater urbanization continues unabated across the globe. According to the United Nations, by 2025 closes to 5 billion people will live in urban areas. Many cities, especially in the developing world, are set to explode in size. Over the next decade and a half, Lagos is...

We present a theory of spinoffs in which the key ingredient is the originator's private information concerning the quality of his new idea. Because quality is privately observed, by the standard adverse-selection logic, the market can at best offer a price that reflects the average quality of...

We propose a theory of firm dynamics in which workers have ideas for new projects that can be sold in a market to existing firms or implemented in new firms: spin-offs. Workers have private information about the quality of their ideas. Because of an adverse selection problem, workers can sell...

We report nonparametrically estimated nonlinear stochastic transition kernels for the evolution of the distribution of populations of metropolitan areas, for the period 1900 to 1990, based on US Census data. Comparison of kernels across successive time periods with the kernel for a pooled sample...

We use data for metro areas in the United States, from the US Census for 1900 - 1990, to test the validity of Zipf's Law for cities. Previous investigations are restricted to regressions of log size against log rank. In contrast, we use a nonparametric procedure to calculate local Zipf exponents...

We test implications of economic geography models for location, size and growth of cities with US Census data for 1900 û 1990. Our tests involve non-parametric estimations of stochastic kernels for the distributions of city sizes and growth rates, conditional on various measures of market...