How large are the welfare gains from trade? Would such gains be significantly amplified in the long run when productivity is endogenously enhanced? To address these questions, we focus on the dynamic effect of trade, in particular, how trade affects the incentives for technological advancement....

Most firms achieve perfective progress, incrementally improving commodities or productivity. But technological progress is concentrated in a few firms achieving metamorphic progress: forming or transforming industries with technological breakthroughs (e.g., biotechnology, lasers, semiconductors,...

To explain why trade restrictions sometimes speed up worldwide growth and sometimes slow it down, we exploit an analogy with the theory of consumer behavior. substitution effects make demand curves slope down, but income effects can increase or decrease the slope, and can sometimes overwhelm the...

We study the incentive that a government in the South has to protect the intellectual property rights of Northern firms, and the consequences of the decision taken by the South for welfare in the North and for efficiency of the world equilibrium. We conduct our analysis in the context of a...

We present a model of growth and technology transfer based on the idea that technologies are specific to particular combinations of inputs. We argue that this model is more realistic than the usual specification, in which an improvement in any technique for producing a given good improves all...

We study the lags with which new technologies are adopted across countries, and their long-run penetration rates once they are adopted. Using data from the last two centuries, we document two new facts: there has been convergence in adoption lags between rich and poor countries, while there has...

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...

We estimate productivities at the sector level for 72 countries and 5 decades, and examine how they evolve over time in both developed and developing countries. In both country groups, comparative advantage has become weaker: productivity grew systematically faster in sectors that were initially...

We construct a model of the product cycle featuring endogenous innovation and endogenous technology transfer. Competitive entrepreneurs in the North expend resources to bring out new products whenever expected present discounted value of future oligopoly profits exceeds current product...

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...