We develop a model in which innovations in an economy's growth potential are an important driving force of the business cycle. The framework shares the emphasis of the recent "new shock" literature on revisions of beliefs about the future as a source of fluctuations, but differs by tieing these...

Aggregate and sectoral comovement are central features of business cycle data. Therefore, the ability to generate comovement is a natural litmus test for macroeconomic models. But it is a test that most existing models fail. In this paper we propose a unified model that generates both aggregate...

This paper studies the implications of financial market imperfections represented by a countercyclical external finance premium and the gradual recognition of changes in the drift of technology growth for the design of an interest rate rule. Asset price movements induced by changes in trend...

In this paper we investigate the sources of the important shifts in the volatility of U.S. macroeconomic variables in the postwar period. To this end, we propose the estimation of DSGE models allowing for time variation in the volatility of the structural innovations. We apply our estimation...

Structural vector autoregressions give conflicting results on the effects of technology shocks on hours. The results depend crucially on the assumed data generating process for hours per capita. We show that the standard measure of hours per capita has significant low frequency movements that...

We explore the response of employment (unemployment) skill differentials to skill-biased shifts in demand touched off by the new and spreading technologies. We find that skill differentials in unemployment follow at least in part the same pattern as skill differentials in wages: They widen...