The gap between U.S. and European productivity is growing, but this isn't due to a lack of innovation, says Bart Van Ark, a professor at the University of Manchester. Despite strength in scientific research, fragmented capital markets, regulatory barriers and weak coordination are limiting the scaling of new technologies, Van Ark says at the ECB Forum in Sintra. Artificial intelligence highlights this challenge. While Europe trails the U.S. in developing frontier AI, it could still capture major productivity gains through applications in manufacturing, healthcare and services, he says. But simply increasing investment won't be enough, he says. The solution is to better enhance industrial policy with competition, education and market integration, Van Ark says. (don.forbes@wsj.com)