Data on energy and mineral reserves suggest that natural resource abundance has not been a significant structural determinant of economic growth between 1970 and 1989. The story behind the effect of natural resources on economic growth is a complex one that typical growth regressions do not capture well. Preliminary evidence suggests that natural resources may affect economic growth through both "positive" and "negative channels." Potential reverse causality running from these "channels" to fuel and mineral reserves further complicates the analysis. I conjecture that, as economic historians suggest, the ability of a country to exploit its resource base depends critically on the nature of the learning process involved.