The ratio of global trade to GDP declined by nearly 30 percent during the global recession of 2008-2009. This large drop in international trade has generated significant attention and concern. Did the decline simply reflect the severity of the recession for traded goods industries? Or...

We develop a Ricardian model to explore the role of trade in spreading the benefits of innovation. The theory delivers an equation for bilateral trade that, on its surface, resembles a gravity specification, but identifies underlying parameters of technology. We estimate the equation using trade...

Customs data reveal heterogeneity and granularity of relationships among buyers and sellers. A key insight is how more exports to a destination break down into more firms selling there and more buyers per exporter. We develop a quantitative general equilibrium model of firm-to-firm matching...

Climate policies vary widely across countries, with some countries imposing stringent emissions policies and others doing very little. When climate policies vary across countries, energy-intensive industries have an incentive to relocate to places with few or no emissions restrictions, an effect...

We derive the optimal unilateral policy in a general equilibrium model of trade and climate change where one region of the world imposes a climate policy and the rest of the world does not. A climate policy in one region shifts activities—extraction, production, and consumption—in the other...

We develop a parsimonious model of innovating firms rich enough to confront firm-level evidence. It captures the dynamic behavior of individual heterogeneous firms, describes the evolution of an industry with simultaneous entry and exit, and delivers a general equilibrium model of technological...