To account for the uneven distribution of economic activity in space, I propose a theory of the location choices of heterogeneous firms in a variety of sectors across cities. In equilibrium, the distribution of city sizes and the sorting patterns of firms are uniquely determined and affect aggregate TFP and welfare. I estimate the model using French firm-level data and find that nearly half of the productivity advantage of large cities is due to firm sorting, the rest coming from agglomeration economies. I quantify the general equilibrium effects of place-based policies: policies that subsidize smaller cities have negative aggregate effects. (JEL D22, D24, R11, R32)

Tourism is a fast-growing services sector in developing countries. This paper combines a rich collection of Mexican microdata with a quantitative spatial equilibrium model and a new empirical strategy to study the long-term economic consequences of tourism both locally and in the aggregate. We find that tourism causes large and significant local economic gains relative to less touristic regions that are in part driven by significant positive spillovers on manufacturing. In the aggregate, however, these local spillovers are largely offset by reductions in agglomeration economies among less touristic regions, so that the national gains from trade in tourism are mainly driven by a classical market integration effect. (JEL L60, L83, O14, O18, R11, Z31, Z32)

Abstract We study optimal spatial policies in a quantitative trade and geography framework with spillovers and spatial sorting of heterogeneous workers. We characterize the spatial transfers that must hold in efficient allocations, as well as labor subsidies that can implement them. There exists scope for welfare-enhancing spatial policies even when spillovers are common across locations. Using data on U.S. cities and existing estimates of the spillover elasticities, we find that the U.S. economy would benefit from a reallocation of workers to currently low-wage cities. The optimal allocation features a greater share of high-skill workers in smaller cities relative to the observed allocation. Inefficient sorting may lead to substantial welfare costs.

We study optimal income taxation in a spatial equilibrium model with heterogeneous locational preferences, labor supply decisions, and competitive housing and labor markets. Expressions characterizing the optimal tax schedule in each community are provided that capture the fiscal externalities associated with migration and the effects of redistribution between households and landlords. Correlation between skill and locational preferences yields optimal transfers to poor areas, while sorting based on comparative advantage can motivate transfers in either direction. A calibration to areas targeted by the US Empowerment Zone program yields sizable optimal spatial transfers that are sensitive to assumed levels of migration responsiveness. (JEL H21, H23, H24, J24, J31, R23)

Large firms play a pivotal role in international trade. We develop a multisector granular model of trade where sectors host a finite number of firms. Both aggregate and granular firm-level forces shape comparative advantage. The model is estimated using French microdata on firm domestic and export sales. We find that granularity accounts for about 20% of the sectoral variation in export intensity and is more pronounced in highly export-intensive sectors. An extension to a dynamic environment with both idiosyncratic and aggregate shocks reveals that firm dynamics plays a central role in shaping comparative advantage reversals observed in the data.

Abstract We explore the impact of rising incomes at the top of the distribution on spatial sorting patterns within large U.S. cities. We develop and quantify a spatial model of a city with heterogeneous agents and non-homothetic preferences for neighbourhoods with endogenous amenity quality. As the rich get richer, demand increases for the high-quality amenities available in downtown neighbourhoods. Rising demand drives up house prices and spurs the development of higher quality neighbourhoods downtown. This gentrification of downtowns makes poor incumbents worse off, as they are either displaced to the suburbs or pay higher rents for amenities that they do not value as much. We quantify the corresponding impact on well-being inequality. Through the lens of the quantified model, the change in the income distribution between 1990 and 2014 led to neighbourhood change and spatial resorting within urban areas that increased the welfare of richer households relative to that of poorer households, above and beyond rising nominal income inequality.