Existing indicators of technical change are plagued by shortcomings. I present new measures based on books published in the field of technology that resolve many of these problems and use them to identify the impact of technology shocks on economic activity. They are positively linked to changes in R&D and scientific knowledge, and capture the new technologies' commercialization dates. Changes in information technology are found to be important sources of economic fluctuations in the post-WWII period, and total factor productivity, investment, and, to a lesser extent, labor are all shown to increase following a positive technology shock. (JEL E22, E23, E32, O33, O34, O47)

New indicators, based on technology titles, are used to measure the impact of innovative activity on the U.S. labor market between 1909 and 1949. We find that positive technology shocks raised productivity, employment, vacancies, and labor turnover and lowered unemployment and business failures. Moreover, automotive and electrical innovations (quintessential general-purpose technologies) had a greater positive impact on employment than those in mechanical innovations. The overall results, compatible with the predictions of the real business cycle model, raise questions about the anemic recovery in employment after 1934 since the strong upsurge in technical change failed to be accompanied by vigorous job expansion.