We inject aggregate uncertainty - risk and ambiguity - into an otherwise standard business cycle model and describe its consequences. We find that increases in uncertainty generally reduce consumption, but they do not account, in this model, for either the magnitude or the persistence of the...

This paper characterizes a robust optimal policy rule in a simple forward-looking model, when the policymaker faces uncertainty about model parameters and shock processes. We show that the robust optimal policy rule is likely to involve a stronger response of the interest rate to fluctuations in...

The paper considers optimal monetary stabilization policy in a forward-looking model, when the central bank recognizes that private-sector expectations need not be precisely model-consistent, and wishes to choose a policy that will be as good as possible in the case of any beliefs that are close...

We study the problem of a policymaker who seeks to set policy optimally in an economy where the true economic structure is unobserved, and he optimally learns from observations of the economy. This is a classic problem of learning and control, variants of which have been studied in the past, but...

The great contraction of 2008 pushed the U.S. economy into a protracted liquidity trap (i.e., a long period with zero nominal interest rates and inflationary expectations below target). In addition, the recovery was jobless (i.e., output growth recovered but unemployment lingered). This paper...

The persistence of U.S. unemployment has risen with each of the last three recessions, raising the specter that future U.S. recessions might look more like the Eurosclerosis experience of the 1980s than traditional V-shaped recoveries of the past. In this paper, we revisit possible explanations...

This paper studies optimal monetary policy under dynamic debt deleveraging once the zero bound is binding. Unlike the existing literature, the natural rate of interest is endogenous and depends on macroeconomic policy. Optimal monetary policy successfully raises the natural rate of interest by...

We propose an overlapping generations New Keynesian model in which a permanent (or very persistent) slump is possible without any self-correcting force to full employment. The trigger for the slump is a deleveraging shock, which creates an oversupply of savings. Other forces that work in the...

In this paper, we use cross-industry, cross-country panel data to test whether industry growth is positively affected by the interaction between the reactivity of real short term interest rates to the business cycle and industry-level measures of financial constraints. Financial constraints are...

This paper uses a New Keynesian model with banks and deposits to study the macroeconomic effects of policies that pay interest on reserves. While their effects on output and inflation are small, these policies require major adjustments in the way that the monetary authority manages the supply of...