We introduce firm and worker heterogeneity into a model of innovation-driven endogenous growth. Individuals who differ in ability sort into either a research sector or a manufacturing sector that produces differentiated goods. Each research project generates a new variety of the differentiated...

We develop a simple model of international trade with heterogeneous firms that is consistent with a number of stylized features of the data. In particular, the model predicts positive as well as zero trade flows across pairs of countries, and it allows the number of exporting firms to vary...

We introduce firm and worker heterogeneity into a model of innovation-driven endogenous growth. Individuals who differ in ability sort into either a research sector or a manufacturing sector that produces differentiated goods. Each research project generates a new variety of the differentiated...

This Economica Coase Lecture reviews research that has revolutionized the field of international trade and foreign direct investment. It explains the motivation behind the development of new analytical frameworks, the nature of these frameworks, and the empirical studies that sprouted from them