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.

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.

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.

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.