The Great Moderation in the US economy has been accompanied by large changes in the comovements among output, hours, and labor productivity. Those changes are reflected in both conditional and unconditional second moments as well as in the impulse responses to identified shocks. Among other...

We develop a simple growth model with imperfect competition in which demand conditions can affect the dynamics of capital accumulation, hindering or enhancing growth. In our model the elasticity of the demand schedule faced by a typical firm depends on the aggregate savings rate. The latter...

Recent evidence on the effect of government spending shocks on consumption cannot be easily reconciled with existing optimizing business cycle models. We extend the standard New Keynesian model to allow for the presence of rule-of-thumb (non-Ricardian) consumers. We show how the interaction of...

We develop a utility based model of fluctuations, with nominal rigidities, and unemployment. In doing so, we combine two strands of research: the New Keynesian model with its focus on nominal rigidities, and the Diamond-Mortensen-Pissarides model, with its focus on labor market frictions and...

Recent evidence on the effect of government spending shocks on consumption cannot be easily reconciled with existing optimizing business cycle models. We extend the standard New Keynesian model to allow for the presence of rule-of-thumb (non-Ricardian) consumers. We show how the interaction of...

We document three changes in postwar US macroeconomic dynamics: (i) the procyclicality of labor productivity has vanished, (ii) the relative volatility of employment has risen, and (iii) the relative (and absolute) volatility of the real wage has risen. We propose an explanation for all three...

We study the optimal monetary policy problem in a New Keynesian economy with a zero lower bound (ZLB) on the nominal interest rate, when the steady state natural rate (r*) becomes permanently negative. We show that the optimal policy aims to approach gradually a new steady state with positive...

Recent evidence on the effect of government spending shocks on consumption cannot be easily reconciled with existing optimizing business cycle models. We extend the standard New Keynesian model to allow for the presence of rule-of-thumb (non-Ricardian) consumers. We show how the interaction of...

We analyze the welfare impact of greater wage flexibility while taking into account explicitly the existence of the zero lower bound (ZLB) constraint on the nominal interest rate. We show that the ZLB constraint generally amplifies the adverse effects of greater wage flexibility on welfare when...

Most central banks perceive a trade-off between stabilizing inflation and stabilizing the gap between output and desired output. However, the standard new Keynesian framework implies no such trade-off. In that framework, stabilizing inflation is equivalent to stabilizing the welfare-relevant...