A growing literature seeks to understand how the characteristics of firms shape the manner in which they serve foreign markets. We consider an environment in which multiproduct firms can sell their products in multiple countries from multiple locations. We show that there are strong empirical...

Firm size follows Zipf's Law, a very fat-tailed distribution that implies a few large firms account for a disproportionate share of overall economic activity. This distribution of firm size is crucial for evaluating the welfare impact of economic policies such as barriers to entry or trade...

Many economic decisions involve a binary choice - for example, when consumers decide to purchase a good or when firms decide to enter a new market. In such settings, agents' choices often depend on imperfect expectations of the future payoffs from their decision (expectational error) as well as...

In what order should a developing country adopt policy reforms? Do some policies complement each other? Do others substitute for each other? To address these questions, we develop a two-country dynamic general equilibrium model with entry and exit of firms that are monopolistic competitors. The...

Japanese exports between 1880 and 1910 increased massively in volume, changed composition, and shifted away from leading industrialized countries toward poorer Asian neighbors. The product mix also varied with the level of development of the destination, with new products and specializations...

I develop a new theory of marketing costs and introduce it into a model of trade with product differentiation and firm productivity heterogeneity. In this model, a firm enters a market if it makes profits by reaching a single consumer there and pays an increasing marginal cost to access...

We show in a multi-sector, heterogeneous-firm trade model that the effect of tariffs on entry, especially in the presence of production linkages, can reverse the traditional positive optimal tariff argument. We then use a new tariff dataset, and apply it to a 189-country, 15-sector version of...

Exporting firms often enter foreign markets that are similar to previous export destinations. We develop a dynamic model in which a firm's exports in a market may depend on how similar the market is to the firm's home country (gravity) and to its previous export destinations (extended gravity)....

We show that a trade model with an exogenous set of heterogeneous firms with fixed operating costs has the same aggregate outcomes as a span-of-control model. Fixed costs in the heterogeneous-firm model are entrepreneurs' forgone wage in the span-of-control model