Human capital plays an important role in the theory of economic growth, but it has been difficult to measure this abstract concept. We survey the psychological literature on cross-cultural IQ tests, and conclude that modern intelligence tests are well-suited for measuring an important form of a...

I show that in a conventional Ramsey model, between one-fourth and one- half of income differences across countries can be explained by a single factor: The steady-state effect of large, persistent differences in national average IQ on worker productivity. These differences in cognitive...

Brownlie and Saren (this issue) claim that “few innovative papers appear in the top marketing journals.” They attribute this problem to incentive structures. They ask what steps might be taken by the various stakeholders to encourage the development and transmission of useful innovative...