In this article, we examine the effect of the imperfect mobility of goods on international risk sharing and, through that, on the investment in risky projects, welfare and growth. We find that the welfare gain of financial market openness is not monotonic with respect to investors' risk aversion...

Many industries are geographically concentrated. Many mechanisms that could account for such agglomeration have been proposed. We note that these theories make different predictions about which pairs of industries should be coagglomerated. We discuss the measurement of coagglomeration and use...

The returns to face-to-face interactions are of central importance to understanding the determinants of agglomeration. However, the existing literature studying patterns of geographic proximity in patent citations or industrial co-location has struggled to disentangle the benefits of...

Should China build mega-cities or a network of linked middle-sized metropolises? Can Europe's mid-sized cities compete with global agglomeration by forging stronger inter-urban links? This paper examines these questions within a model of recombinant growth and endogenous local amenities. Three...

People continue to live in many big American cities, because in those cities housing costs less than new construction. While cities may lose their productive edge, their houses remain and population falls only when housing depreciates. This paper presents a simple durable housing model of urban...

Crime rates are much higher in big cities than in either small cities or rural areas, and this situation has been relatively pervasive for several centuries. This paper attempts to explain this connection by using victimization data, evidence from the NLSY on criminal behavior and the Uniform...

Many of the world's largest cities are now in developing countries. We develop a simple theoretical model, inspired by the case of Mexico, that explains the existence of such giant cities as a consequence of the strong forward and backward linkages that arise when manufacturing tries to serve a...

We study optimal dynamic lockdowns against Covid-19 within a commuting network. Our framework integrates canonical spatial epidemiology and trade models, and is applied to cities with varying initial viral spread: Seoul, Daegu and NYC-Metro. Spatial lockdowns achieve substantially smaller income...

Current U.S. law nets the total portfolio of realized capital gains and losses to compute capital gains taxes. Prior research, however, typically ignores the implication of this provision, i.e., the marginal tax rate for a specific gain or loss depends on the taxpayer's total portfolio of...