Technological change is often measured by economists and economic historians through productivity growth, but this article argues that technological change and productivity change are conceptually different. This proposition is demonstrated by considering the diffusion of technologies first within industries, and second across industries. In both cases, economic growth reaches higher levels when the technology becomes diffused, not when it is being generated via major technological breakthroughs. This emerges through high ratios of patents (as a measure of technological change) to industrial production when countries undergo their industrial revolutions. Finally I compare across countries, to show that leader countries developed the technologies before they developed education systems to extend them, whereas some catching-up countries probably drew on their depth of human capital to absorb new technologies from the leaders.