This paper develops and analyzes a macroeconomic model in which aggregate growth and fluctuations arise from the discovery and diffusion of new technologies; there are no exogenous aggregate shocks. The temporal behavior of aggregates is driven by individuals' efforts to innovate and/or make use...

We investigate the controversial issue whether unemployment is related to productivity growth in the long run, using U.S. data in a framework of infrequent mean shifts. Tests find (endogenously dated) shifts around 1974, 1986, and 1996, system techniques indicate that the shifts are common...

The accumulation of knowledge and its application to a variety of human needs is a discontinuous process that involves innovation and change. While much has been written on major discontinuities associated, for instance, with the rise of new technologies during industrial revolutions, other...