We consider a production economy with a finite number of heterogeneous, infinitely lived consumers. We show that, if the economy is smooth enough, equilibria are locally unique for almost all endowments. We do so by converting the infinite-dimensional fixed point problem stated in terms of...

We characterize equilibria of general equilibrium models with externalities and taxes as solutions to optimization problems. This characterization is similar to Negishi’s characterization of equilibria of economies without externalities or taxes as solutions to social planning problems. It is...

This paper suggests that innovation policy in the United States has erred by subsidizing the private sector demand for scientists and engineers without asking whether the educational system provides that supply response necessary for these subsidies to work. It suggests that the existing...

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...

When they are used together, economic history and new growth theory give a more complete picture of technological change than either can give on its own. An empirical strategy for studying growth that does not use historical evidence is likely to degenerate into sterile model testing exercises....

The typical economic model implicitly assumes that the set of goods in an economy never changes. As a result, the predicted efficiency loss from a tariff is small, on the order of the square of the tariff rate. If we loosen this assumption and assume that international trade can bring new goods...

This paper outlines a theoretical framework for thinking about the role of human capital in a model of endogenous growth. The framework pays particular attention to two questions: What are the theoretical differences between intangibles like education and experience on the one hand, and...

From the beginning, growth theory has been faced with technically challenging questions about increasing returns and the way to capture ideas in a model of market exchange. Initially, reliance on perfect competition forced growth theory to narrow its scope. Recently, new tools for studying...

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...