In the aftermath of World War II, the world's economies exhibited very dierent rates of economic recovery. We provide evidence that those countries that caught up the most with the U.S. in the postwar period are those that also saw an acceleration in the speed of adoption of new technologies. This acceleration is correlated with the incidence of U.S. economic aid and technical assistance in the same period. We interpret this as supportive of the interpretation that technology transfers from the U.S. to Western European countries and Japan were an important factor in driving growth in these recipient countries during the postwar decades.