this volume deals with shiftwork-work that is performed during other than normal daytime hours. shiftwork is a characteristic of economic life in the united states and abroad and has increased in importance over the years. the book examines changes in weekly hours worked by fixed capital over long periods of time, and the significance of those changes in the measurement of long-run productivity change. the analysis provides a link between a technology rooted in physical capital with one rooted in human capital. shiftwork, capital hours and productivity change, which emphasizes empirical research, should be of interest because of its use of original data, because of the progressive nature of the research, and because it ultimately brings that research to bear on a number of issues that are in the forefront of public discussion. making use of the new multifactor productivity statistics that are now being published by the u.s. bureau of labor statistics for detailed (two-digit) manufacturing industries for the postwar period, the author shows the changing influence of plant-hour change from the 1920s to the 1980s.