We generalize the closed-economy neoclassical growth model (CNGM) to allow for costly goods trade and capital flows with imperfect substitutability between countries. We develop a tractable, multi-country, quantitative model that matches key features of the observed data (e.g., gravity equations...

Despite the fact that importing and exporting are extremely rare firm activities, economists generally devote little attention to the role of firms when discussing international trade. This paper summarizes key differences between trading and non-trading firms, demonstrates how these differences...

Research in international trade has changed dramatically over the last twenty years, as attention has shifted from countries and industries towards the firms actually engaged in international trade. The now-standard heterogeneous firm model posits measure zero firms that compete under...

Since the 1990s, R&D has become less geographically concentrated, and has seen especially fast growth in emerging markets. One of the distinguishing features of the R&D globalization phenomenon is its concentration within the software/IT domain; the increase in foreign R&D has been largely...

The location of US multinational foreign R&D has shifted significantly to include emerging markets in addition to traditional Western R&D hubs, resulting in two challenges for multinationals: (1) how to transfer knowledge across geographic distances, and (2) how to facilitate learning when local...

We examine firm participation in global supply chains to help explain a puzzling decline in protectionist demands in the U.S. despite increased import competition and ongoing currency undervaluation. To explain firm responses to undervaluation, we rely on advances in the international trade...

This paper reviews the recent theoretical literature on heterogeneous firms and trade, which emphasizes firm selection into international markets and reallocations of resources across firms. We discuss the empirical challenges that motivated this research and its relationship to traditional...

This paper develops a new framework for examining the distributional consequences of trade liberalization that is consistent with increasing inequality in every country, growth in residual wage inequality, rising unemployment, and reallocation within and between industries. While the opening of...

We develop a model of human interaction to analyze the relationship between globalization and pandemics. Our framework provides joint microfoundations for the gravity equation for international trade and the Susceptible-Infected-Recovered (SIR) model of disease dynamics. We show that there are...

We develop a new framework for aggregating from micro to macro patterns of trade. We derive price indexes that determine comparative advantage across countries and sectors and the aggregate cost of living. If firms and products are imperfect substitutes, we show that these price indexes depend...