This paper investigates an empirical puzzle in technology adoption for developing countries: the low adoption rates of technologies like hybrid maize that increase average farm profits dramatically. I offer a simple explanation for this: benefits and costs of technologies are heterogeneous, so...

We develop a Ricardian model to explore the role of trade in spreading the benefits of" innovation. The theory delivers an equation for bilateral trade that gravity specification, but identifies underlying parameters of technology. We estimate the" equation using trade in manufactures among the...

The "market for innovation" -- the sale and licensing of patents -- is an often discussed source of incentives to invest in R&D. This article presents and estimates a model of the transfer and renewal of patents that, under some assumptions, allows us to quantify the gains resulting from the...

Economists devote too much attention to international flows of goods and services and not enough to international flows of ideas. Traditional trade flows are an imperfect substitute for flows of the underlying ideas. The simplest textbook trade model shows that a welfare-enhancing move toward...

Convergence in per capita income turns on whether technological knowledge spillovers are global or local. Global spillovers favor convergence, while a geographically limited scope of knowledge diffusion can lead to regional clusters of countries with persistently different levels of income per...

We study how opening to trade affects economic growth in a model where heterogeneous firms can adopt new technologies already in use by other firms in their home country. We characterize the growth rate using a summary statistic of the profit distribution—the mean-min ratio. Opening to trade...

Trade is measured on a gross sales basis while GDP is measured on a net sales basis, i.e. value added. The rapid internationalisation of production in the last two decades has meant that gross trade flows are increasingly unrepresentative of the value added flows. This fact has important...

We develop a quantitative spatial model that incorporates a rich geography of trade and imperfect labor mobility between locations. We provide general results for the existence, uniqueness and comparative statics of the equilibrium. We show how the model can be used to undertake counterfactuals...

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

In this paper, I survey the recent theoretical literature that incorporates heterogeneous labor into models of international trade. The models with heterogeneous labor have been used to study how talent dispersion can be a source of comparative advantage, how the opening of trade affects the...