This paper builds on earlier evidence showing that, while most countries exhibit little evidence of unconditional income convergence, countries that trade heavily with one another tend to exhibit a much higher incidence of convergence. Two alternative explanations for the trade-related convergence are explored here. The first alternative is that the trade-related income convergence is due to a convergence in capital-labor ratios. Little support is found for this explanation. The other alternative examined here is that of a trade-related convergence in technologies. This alternative is corroborated by a high incidence of convergence in total factor productivities among countries that trade heavily with one another - an outcome that is not common between these same countries when they are grouped randomly rather than on the basis of trade.