This chapter reviews the new approach to international trade based on firm heterogeneity in
differentiated product markets. This approach explains a variety of features exhibited in …

This article reviews the empirical evidence on firm heterogeneity in international trade. A first
wave of empirical findings from microdata on plants and firms proposed challenges for …

This paper examines the importance of buyer-supplier relationships for firm performance.
We develop a model in which firms outsource tasks and search for suppliers. Lower search …

We build a tractable growth model in which multiproduct incumbents invest in internal
innovations to improve their existing products, while new entrants and incumbents invest in …

In a dynamic model with sunk export costs, a firm's export investment is lower under trade
policy uncertainty, and credible preferential trade agreements (PTAs) increase trade even if …

We study the gains from trade liberalization in models with monopolistic competition, firm-
level heterogeneity, and variable markups. For a large class of demand functions used in the …

A power law (PL) is the form taken by a large number of surprising empirical regularities in
economics and finance. This review surveys well-documented empirical PLs regarding …

This paper develops a novel theory of marketing costs within a trade model with product
differentiation and heterogeneity in firm productivities. A firm enters a market if it is profitable …

Exporting firms often enter foreign markets that are similar to their previous export
destinations. We develop a dynamic model in which a firm's exports in a market may depend …

We present a general equilibrium model of the response of firms' decisions to operate,
innovate, and engage in international trade to a change in the marginal cost of international …