Natural and agricultural resources for which there is a substantial black market, such as coca, opium, and diamonds, appear especially likely to be exploited by the parties to a civil conflict. On the other hand, these resources may also provide one of the few reliable sources of income in the...

Empirical research on cities starts with a spatial equilibrium condition: workers and firms are assumed to be indifferent across space. This condition implies that research on cities is different from research on countries, and that work on places within countries needs to consider population,...

This paper studies the real estate brokerage industry in Greater Boston, an industry with low entry barriers and substantial turnover. Using a comprehensive dataset of agents and transactions from 1998-2007, we find that entry does not increase sales probabilities or reduce the time it takes for...

We develop a spatial model of energy exploitation where energy sources are differentiated by their geographic location and energy density. The spatial setting creates a scaling law that magnifies the importance of differences across energy sources. As a result, renewable sources twice as dense,...

A large agronomic literature models the implications of climate change for a variety of crops and locations around the world. The goal of the present paper is to quantify the macro-level consequences of these micro-level shocks. Using an extremely rich micro-level dataset that contains...

Measures of entrepreneurship, such as average establishment size and the prevalence of start-ups, correlate strongly with employment growth across and within metropolitan areas, but the endogeneity of these measures bedevils interpretation. Chinitz (1961) hypothesized that coal mines near...

This paper examines city formation in a country whose urban population is growing steadily over time, with new cities required to accommodate this growth. In contrast to most of the literature there is immobility of housing and urban infrastructure, and investment in these assets is taken on the...

This study examines the spatial distribution of Muslim societies shedding light on its geographic origins. The empirical analysis conducted across countries, virtual countries, and ethnicities establishes that geographic inequality and proximity to pre-Islamic trade routes are fundamental...

It is striking how often countries with oil or other natural resource wealth have failed to grow more rapidly than those without. This is the phenomenon known as the Natural Resource Curse. The principle has been borne out in some econometric tests of the determinants of economic performance...

The Schelling model of a "tipping point" in racial segregation, in which whites flee a neighborhood once a threshold of nonwhites is reached, is a canonical model of strategic interdependence. The idea of "tipping" explaining segregation is widely accepted in the academic literature and popular...