Did Technology Transfer More Rapidly East-West than North-South?

We offer evidence of the role of continental orientation in the historical diffusion of technologies. Diamond (1997) argued that technologies spread more slowly North-South (N-S) than East-West (E-W) for two reasons. First, it was relatively costly for individuals to transport innovations when experiencing N-S variations in climate. Second, some innovations (e.g, selectively bred seeds) would have been less likely to survive N-S movements. Continents with E-W orientation, then, were characterized by less costly and/or more successful sharing of technologies. We employ Comin et al.'s (2010) data on ancient and early modern levels of technology adoption in a spatial econometric analysis. Historical levels of technology adoption in a (present-day) country are related to its lagged level as well as those of its neighbors. The E- W spatial correlations are generally larger, more likely to be positive, and more likely to be statistically significant. While acknowledging that the difference between E-W and N-S effects is not significant in every estimation, taken together the results offer compelling support for the Diamond hypothesis