We develop a Ricardian model of trade in which countries innovate ideas that diffuse across the globe. In this model, the forces of innovation and diffusion combine to shape trade substitution patterns. Innovation makes a country technologically distinct, reducing their substitutability with...

Large-scale financial and macroeconomic shocks directly affect some firms and households and indirectly impact others through general equilibrium spillovers. In this paper, I describe how researchers can estimate spillovers directly using quasi-experimental or experimental variation. I then...

The comparative advantage of many cities is based on their efficiency in the production of 'functions', e.g., business services such as finance, law, engineering, or similar functions that are used by firms in a wide range of sectors. Firms that use these functions may choose to source them...

Exploiting a large migration of farmers to the West of Brazil between 1950 and 2010, we study how migration shapes aggregate and regional comparative advantage. We document that farmers emigrating from regions with high employment in an activity are more likely to work in that activity and have...

This paper highlights a tradeoff implied by a policy of export-led growth through currency undervaluation. While undervaluation can foster domestic manufacturing in countries like China by sustaining trade surplus, it also can harm a country's comparative advantage by altering the composition of...

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 that...

This paper documents a new fact, then analyzes its causes and consequences: in most countries, import tariffs and non-tariff barriers are substantially lower on dirty than on clean industries, where an industry's "dirtiness" is defined as its carbon dioxide (CO2) emissions per dollar of output....

The flow of resources across sectors to their best use, with concomitant entry and exit, is central to the functioning and welfare properties of a market economy. Nevertheless, most industrial organization research, including applications to competition policy, undertakes partial equilibrium...

In absence of insurance contracts to share risk, public information is a double-edged sword. On the one hand, it empowers self-insurance as agents better react to shocks, reducing risk. On the other hand, it weakens market-insurance as common knowledge of shocks restricts trading risk. We embody...

I give conditions under which changes in private spending are accommodated in general equilibrium exactly like changes in aggregate fiscal expenditure. Under such demand equivalence, researchers can use time series evidence on fiscal multipliers to recover the general equilibrium "missing...