Labor Mobility
Working Papers
Abstract: We evaluate how anticipation and adaptation shape the aggregate and local costs of climate change. We develop a dynamic spatial model of the U.S. economy and its 3,143 counties that features costly forward-looking migration and capital investment decisions. Recent methodological advances that leverage the ‘Master Equation’ representation of the economy make the model tractable. We estimate the county-level impact of severe storms and heat waves over the 20th century on local income, population, and investment. The estimated impact of storms matches that of capital depreciation shocks in the model, while heat waves resemble combined amenity and productivity shocks. We then estimate migration and investment elasticities, as well as the structural damage functions, by matching these reduced-form results in our framework. Our findings show, first, that the impact of climate on capital depreciation magnifies the U.S. aggregate welfare costs of climate change twofold to nearly 5% in 2023 under a business-as-usual warming scenario. Second, anticipation of future climate damages amplifies climate-induced worker and investment mobility, as workers and capitalists foresee the slow build-up of climate change. Third, migration reduces substantially the spatial variance in the welfare impact of climate change. Although both anticipation and migration are important for local impacts, their effect on aggregate U.S. losses from climate change is small.
Abstract: A unilateral carbon tax trades off the distortionary costs of taxation and the future gains from slowing down global warming. Because the cost is local and immediate, whereas the benefit is global and delayed, this tradeoff tends to be unfavorable to unilateral carbon taxes. We show that this logic breaks down in a world with trade and migration where economic geography is shaped by agglomeration economies and congestion forces. Using a multisector dynamic spatial integrated assessment model (S-IAM), this paper predicts that a carbon tax introduced by the European Union (EU) and rebated locally can, if not too large, increase the size of Europe’s economy by concentrating economic activity in its high-productivity non-agricultural core and by incentivizing immigration to the EU. The resulting change in the spatial distribution of economic activity improves global efficiency and welfare. A unilateral carbon tax with local rebating introduced by the US generates similar global welfare gains. Other forms of rebating can dilute or revert this positive effect.
Abstract: In the U.S., cognitive non-routine (CNR) occupations are disproportionately and increasingly represented in large cities. To study the allocation of workers across cities, we propose a quantitative spatial equilibrium model with multiple industries employing CNR and non-CNR occupations. Productivity is city-industry-occupation specific and, as we estimate, partly determined by externalities that depend on local occupation shares and total employment. An optimal policy that benefits workers equally, incentivizes the formation of cognitive hubs in large cities. It also creates higher overall activity in small cities, greater industrial specialization in both the largest and smallest cities, and greater diversification in medium-sized cities.
Journal Publications
The Economic Geography of Global Warming
Review of Economic Studies, 2024, 91(2): 899-939
Abstract: Global warming is a worldwide and protracted phenomenon with heterogeneous local economic effects. We propose a dynamic economic assessment model of the world economy with high spatial resolution to assess its consequences. Our model features several forms of adaptation to local temperature changes, including costly trade and migration, local technological innovations, and local natality rates. We quantify the model at a 1° × 1° resolution and estimate damage functions that determine the impact of temperature changes on a region’s fundamental productivity and amenities conditional on local temperatures. Welfare losses from global warming are very heterogeneous across locations, with 20% losses in parts of Africa and Latin America but also gains in some northern latitudes. Overall, spatial inequality increases. Uncertainty about average welfare effects is significant, but much smaller for relative losses across space. Migration and innovation are shown to be important adaptation mechanisms. We use the model to study the impact of carbon taxes, abatement technologies, and clean energy subsidies. Carbon taxes delay consumption of fossil fuels and help flatten the temperature curve but are much more effective when an abatement technology is forthcoming.
Abstract: The location of individuals determines their job and schooling opportunities, amenities, and housing costs. We conceptualize the location choice of individuals as a decision to invest in a `location asset'. This asset has a current cost equal to the location's rent, and a future payoff through better job and schooling opportunities. As with any asset, savers in the location asset transfer resources into the future by going to expensive locations with high future returns. In contrast, borrowers transfer resources to the present by going to cheap locations that offer few other advantages. Holdings of the location asset depend on its comparison to other assets, with the distinction that the location asset is not subject to borrowing constraints. We propose a dynamic location model and derive an agent's mobility choices after experiencing income shocks. We document the investment dimension of location and confirm the core predictions of our theory using French individual panel data from tax returns.
Local Industrial Policy and Sectoral Hubs
AEA Papers and Proceedings, 2021, 111: 526-31
Abstract: We study the desirability of industrial policies that generate sectoral hubs using a quantitative spatial model with cognitive non-routine and other occupations. The productivity of each occupation in an industry depends on sector-specific production externalities, which we estimate using a model-implied instrumental variable approach. We find that the optimal policy gives rise to national hubs in coastal cities in tradeable services, like Professional Services, and smaller regional hubs in less tradable services, like Health and Education. The optimal policy prescribes developing Manufacturing in smaller towns. We decompose the implied changes in local costs and the available varieties in each sector.
Commuting, Migration and Local Employment Elasticities
American Economic Review, 2018, 108(12): 3855-3890
Abstract: We provide theory and evidence that the elasticity of local employment to a labor demand shock is heterogeneous depending on the commuting openness of the local labor market. We develop a quantitative general equilibrium model that incorporates spatial linkages in goods markets (trade) and factor markets (commuting and migration). We quantify this model to match the observed gravity equation relationships for trade and commuting. We find that empirically-observed reductions in commuting costs generate welfare gains of around 3.3 percent. We provide separate quasi-experimental evidence in support of the model’s predictions using the location decisions of million dollar plants.
Journal of Political Economy, 2018, 126(3): 903-983
Read more about it in: The Economist
Abstract: We develop a dynamic spatial growth theory with realistic geography. We characterize the model and its balanced-growth path and propose a methodology to analyze equilibria with different levels of migration frictions. Different migration scenarios change local market size, innovation incentives, and the evolution of technology. We bring the model to the data for the whole world economy at a 1° × 1° geographic resolution. We then use the model to quantify the gains from relaxing migration restrictions. Our results indicate that fully liberalizing migration would increase welfare about threefold and would significantly affect the evolution of particular regions of the world.
Abstract: This paper studies the impact of spatial frictions on Asia’s long-term spatial development. Using the framework provided in Desmet, Nagy, and Rossi-Hansberg (2016), we analyze the evolution of Asia’s economy and the relative performance of specific regions and countries. We then perform a number of counterfactual experiments and find that a worldwide drop in transport costs of 40% increases the present discounted value of real income by 70.7% globally and 78% in Asia. These figures are much larger than those found in standard quantitative trade models because they include dynamic effects and take into account intracountry transport costs. We also perform exercises in which we upgrade Asia’s road network or relax migratory restrictions between locations in Asia. These exercises emphasize the important role of spatial frictions in the development of Asia’s economy.
Abstract: This paper studies the recent spatial development of India. Services, and to a lesser extent manufacturing, are increasingly concentrating in high-density clusters. This stands in contrast with the United States, where in the last decades services have tended to grow fastest in mediumdensity locations, such as Silicon Valley. India’s experience is not common to all fast-growing developing economies. The spatial growth pattern of China looks more similar to that in the United States than to that of India. Our findings suggest that certain frictions are keeping medium-density places in India from growing faster.
Abstract: We present a theory of spatial development. Manufacturing and services firms located in a continuous geographic area choose each period how much to innovate. firms trade subject to transport costs and technology diffuses spatially. We apply the model to study the evolution of the US economy in the last half-century and find that it can generate the reduction in the manufacturing employment share, the increased spatial concentration of services, the growth in service productivity starting in the mid-1990s, the rise in the dispersion of land rents in the same period, as well as several other spatial and temporal patterns.