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...

We study a world with national external economies of scale at the industry level. In contrast to the standard treatment with perfect competition and two industries, we assume Bertrand competition in a continuum of industries. In this setting, many of the "pathologies" of the standard treatment...

A new methodology is developed to determine the extent to which import competition has been responsible for labor displacements and wage movements inspecific, allegedly trade-impacted sectors. The procedure involves the estimation of reduced-form wage and employment equations by sector. These...

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...

In industries with imperfect consumer information, the lack of a reputation puts latecomers at a competitive disadvantage vis-a-vis established firms. We consider whether the existence of such informational barriers to entry provides a valid reason for temporarily protecting infant producers of...

We consider a model in which the level of taxes and seignorage are too low to finance government expenditures and debt service. Government debt will therefore grow without bound, implying the eventual need to change policy. Starting with utility maximization, we analyze the effect of the...

We study the positive and normative effects of counterfeiting, i.e.,trademark infringement, in markets where consumers are not deceived by forgeries.The fact that consumers are willing to pay more for counterfeits than for generic merchandise of similar quality suggests that they value the...

We study a simple, two-stage, stochastic patent race involving two firms. We examine the behavior of the participants as they gain the lead or fall behind in the race. We find that the leader engages in R&D more intensively than does the follower, and that both firms intensify their efforts if...

We study the optimal pattern of outlays for a single firm pursuing an R&D program over time. In the deterministic case, (a) the amount of progress required to complete the project is known, and (b) the relationship between outlays and progress is known. In this case, it is optimal to increase...