This paper proposes a simple theory of a system of cities that decomposes the determinants of the city size distribution into three main components: efficiency, amenities, and frictions. Higher efficiency and better amenities lead to larger cities, but also to greater frictions through...

We propose a dynamic spatial theory to analyze the geographic impact of climate change. Agricultural and manufacturing firms locate on a hemisphere. Trade across locations is costly, firms innovate, and technology diffuses over space. Energy used in production leads to emissions that contribute...

This paper proposes a new method to measure ethnolinguistic diversity and offers new results linking such diversity with a range of political economy outcomes -- civil conflict, redistribution, economic growth and the provision of public goods. We use linguistic trees, describing the...

We study the relationship between geography and growth. To do so, we first 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. We...

We investigate the empirical relationship between ethnicity and culture, defined as a vector of traits reflecting norms, attitudes and preferences. Using surveys of individual values in 76 countries, we find that ethnic identity is a significant predictor of cultural values, yet that...

This paper analyzes the importance of local interaction between individuals of different linguistic groups for the provision of public goods at the national level. The micro-founded conceptual framework we develop predicts that a country's public goods (i) decrease in its overall linguistic...

This paper conducts a systematic quantitative study of cultural convergence and divergence in the United States over time. Using the General Social Survey (1972-2016), we assess whether cultural values have grown more or less heterogeneous, both overall and between groups. Groups are defined...

U.S. county data for the last 20 or 30 years show that manufacturing employment has been deconcentrating. In contrast, the service sector exhibits concentration in counties with intermediate levels of employment. This paper presents a theory where local sectoral growth is driven by technological...

We analyze the correlates of COVID-19 cases and deaths across US counties. We consider a wide range of correlates - population density, public transportation, age structure, nursing home residents, connectedness to source countries, etc. - finding that these variables are important predictors of...

Sea-level rise and ensuing permanent coastal inundation will cause spatial shifts in population and economic activity over the next 200 years. Using a highly spatially disaggregated, dynamic model of the world economy that accounts for the dynamics of migration, trade, and innovation, this paper...