Recent research has emphasized firm heterogeneity as a source of comparative advantage. Combining this approach with labor market frictions and worker heterogeneity provides a framework for studying the impact of trade on unemployment and inequality. This paper reviews this approach and reports...

In this paper we develop a multi-sector general equilibrium model of firm heterogeneity, worker heterogeneity and labor market frictions. We characterize the distributions of employment, unemployment, wages and income within and between sectors as a function of structural parameters. We find...

This paper reviews a new framework for analyzing the interrelationship between inequality, unemployment, labor market frictions, and foreign trade. This framework emphasizes firm heterogeneity and search and matching frictions in labor markets. It implies that the opening of trade may raise...

We study a two-country two-sector model of international trade in which one sector produces homogeneous products while the other produces differentiated products. The differentiated-product industry has firm heterogeneity, monopolistic competition, search and matching in its labor market, and...

We survey research on the relationship between technology and trade. We begin with the old literature, which treated the state of technology as exogenous and asked how changes in technology affect the trade pattern and welfare. Recent research has attempted to endogenize technological progress...

In this paper we study how aggregate output responds to the arrival of a new General Purpose Technology (GPT) by looking at adjustment mechanisms that operate through labor markets. We show that under a wide set of circumstances the arrival of a new GPT that raises long-run output can trigger a...

We develop a model of growth driven by successive improvements in 'General Purpose Technologies' (GPT's), such as the steam engine, electricity, or micro-electronics. Each new generation of GPT's prompts investments in complementary inputs, and impacts the economy after enough such compatible...

The evidence for the United States points to balanced growth despite falling investment-good prices and an elasticity of substitution between capital and labor less than one. This is inconsistent with the Uzawa Growth Theorem. We extend Uzawa's theorem to show that the introduction of human...