We quantify how pollution affects aggregate productivity and welfare in spatial equilibrium. We document a robust pattern in which skilled workers in China emigrate away from polluted cities, more than the unskilled. These patterns are evident under various empirical specifications, such as when instrumenting for pollution using distant upwind power-plants, or thermal inversions that trap pollutants. Pollution changes the spatial distribution of skilled and unskilled workers, which increases returns-to-skill in cities that the educated emigrate from. We quantify the loss in aggregate productivity due to this re-sorting by estimating a spatial equilibrium model. Counterfactual simulations show that reducing pollution increases productivity through spatial re-sorting by approximately as much as the direct health benefits of clean air. We identify a new channel through which pollution lowers aggregate productivity significantly. Hukou mobility restrictions exacerbate welfare losses. Skilled workers’ aversion to pollution explains a substantial portion of the wage-gap between cities.

In the United States, rural and low-income communities have difficulty attracting and retaining physicians, potentially adversely impacting health outcomes. With a limited supply of physicians completing medical school at US universities, foreign-born and educated physicians provide a potential source of supply in underserved areas. For international medical school graduates (IMGs) the terms of the commonly used J-1 visa require a return to the home country for two years following employment in medical residency. Our analysis examines the extent to which the Conrad 30 Visa Waiver impacts the supply of physicians at state and local levels, particularly in areas designated as medically underserved. Changes in the federal limit on the number of waivers per state, combined with variation in the state-level restrictions on eligible specialties, and geographies in which physicians can work, provide evidence on the role of visa restrictions in limiting the supply of doctors. Expansion of the cap on visa waivers increased the supply of IMGs, particularly in states that did not limit waiver recipients to primary care physicians or particular places of employment. There is little evidence of reductions in US-trained doctors in states where IMG increases were the largest, suggesting little evidence for crowding out.

We highlight a lesser-known consequence of China’s integration into the world economy: the rise of services trade. We demonstrate how the US’s trade deficit in goods cycles back as a surplus in US exports of education services. Focusing on China’s accession to the World Trade Organization, we show that Chinese cities more exposed to trade liberalization sent more students to US universities. Growth in housing income/wealth allowed Chinese families to afford US tuition, and more students financed their studies using personal funds. Our estimates suggest that recent trade wars could cost US universities around $1.1 bn in annual tuition revenue.

University learning has facilitated the flow of individuals and knowledge across national borders for centuries, but the recent scale of student flows and the magnitude of tuition revenues from foreign students across the globe is unprecedented. The number of students pursuing higher education degrees outside their home countries more than doubled between 2000 and 2017 to reach 5.3 million (UNESCO 2018).

The number of international undergraduate students at US public research universities increased dramatically over the past two decades, alongside concurrent reductions in state support for universities. We show that these trends are closely connected as public research universities relied on foreign students to cushion the effects of falling appropriations. The growing capacity in emerging economies to pay for a US education provided opportunities for universities to recover revenues from full-fare-paying foreign students. We estimate that between 1996 and 2012, a 10 percent reduction in state appropriations led to an increase in foreign enrollment of 16 percent at public research universities. (JEL H75, I22, I23)

We present and calibrate a dynamic model that characterizes the labor market for computer scientists. In our model, firms can recruit computer scientists from recently graduated college students, from STEM workers working in other occupations, or from a pool of foreign talent. Counterfactual simulations suggest that wages for computer scientists would have been 2.8%–3.8% higher and the number of Americans employed as computer scientists 7.0%– 13.6% higher in 2004 if firms could not hire more foreigners than they could in 1994. In contrast, total computer science employment would have been 3.8%–9.0% lower and consequently output smaller.