I show that in a conventional Ramsey model, between one-fourth and one-half of the global income distribution can be explained by a single factor: The effect of large, persistent differences in national average IQ on the private marginal product of labor. Thus, differences in national average IQ...

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...

Software is a potentially excludable public good. It is possible, at some cost, to exclude non-paying users from its consumption by using copyright law or technological restraints. Licensing the software under proprietary license terms makes of it a private good, licensing it under the BSD does...

The TeX typesetting software was developed by Donald E. Knuth in the late 1970s. It was released with an open source license and has become a reference in scientific publishing. TeX is now used to typeset and publish much of the world’s scientific literature in physics and mathematics. This...