Optimal Monetary and Fiscal Policy with a Zero Bound on Nominal Interest Rates

I characterize optimal monetary and fiscal policy in a stochastic New Keynesian model when nominal interest rates may occasionally hit the zero lower bound. The benevolent policymaker controls the short‐term nominal interest rate and the level of government spending. Under discretionary policy, accounting for fiscal stabilization policy eliminates to a large extent the welfare losses associated with the presence of the zero bound. Under commitment, the gains associated with the use of the fiscal policy tool remain modest, even though fiscal stabilization policy is part of the optimal policy mix.     

Fiscal Multipliers at the Zero Lower Bound: The Role of Policy Inertia

The presence of the lagged shadow policy rate in the interest rate feedback rule reduces the government spending multiplier nontrivially when the policy rate is constrained at the zero lower bound (ZLB). In the economy with policy inertia, increased inflation and output due to higher government spending during a recession speed up the return of the policy rate to the steady state after the recession ends, which in turn damps the expansionary effects of the government spending during the recession via expectations. In our baseline experiment intended to capture the effectiveness of the American Recovery and Reinvestment Act of 2009, the output multiplier at the ZLB is 1.9 when the weight on the lagged shadow rate is zero, and 0.5 when the weight is 0.85.     

The Government Spending Multiplier in a (Mis)Managed Liquidity Trap

I study the impact of a government spending shock in a New Keynesian model when monetary policy is set optimally. In this framework, the economy is at the zero lower bound but expectations are well managed by the central bank. As such, the multiplier effect of government spending increases on expected inflation is close to zero while the one on output can be larger than one. This is consistent with recent empirical evidence on the effects of the 2009 American Recovery and Reinvestment Act.     

Macroeconomic Effects of Government Spending: The Great Recession was (Really) Different

We estimate the effect of government spending shocks on the U.S. economy with a time‐varying parameter vector autoregression. The recent Great Recession period appears to be characterized by uniquely large impulse responses of output to fiscal shocks. Moreover, the particularity of this period is underlined by highly unusual responses of several other variables. The pattern of fiscal shock responses neither completely fits the predictions of the New Keynesian model of an economy subject to the zero lower bound on nominal interest rates, nor does it suggest regular variation of fiscal policy effects depending on the state of the business cycle. Rather, the Great Recession period seems special in that government spending shocks had a strongly negative effect on the spread between corporate and government bond yields and a strongly positive effect on consumer confidence and private consumption spending.     

Discretionary monetary policy and the zero lower bound on nominal interest rates

Ignoring the existence of the zero lower bound on nominal interest rates one considerably understates the value of monetary commitment in New Keynesian models. A stochastic forward-looking model with an occasionally binding lower bound, calibrated to the U.S. economy, suggests that low values for the natural rate of interest lead to sizeable output losses and deflation under discretionary monetary policy. The fall in output and deflation are much larger than in the case with policy commitment and do not show up at all if the model abstracts from the existence of the lower bound. The welfare losses of discretionary policy increase even further when inflation is partly determined by lagged inflation in the Phillips curve. These results emerge because private sector expectations and the discretionary policy response to these expectations reinforce each other and cause the lower bound to be reached much earlier than under commitment.     

The Taylor Principle and Monetary Policy Approaching a Zero Bound on Nominal Rates: Quantile Regression Results for the United States and Japan

This paper offers a new approach that estimates the response of interest rates to inflation and the output gap at various points (quantiles) on the conditional distribution of interest rates. This offers an improvement on empirical estimates conducted only at the mean and also allows us to test the propositions that policy shows greater aggression to inflation in the reaction function in terms of a greater response coefficient as interest rates reach low levels, and increasing aggression as the lower bound is approached. We find support for the Taylor principle, a more aggressive response to inflation than under a Taylor rule, but no detectable evidence of increasing aggression as the zero lower bound is approached in the US and Japan.     

Identifying the Stance of Monetary Policy at the Zero Lower Bound: A Markov‐Switching Estimation Exploiting Monetary‐Fiscal Policy Interdependence

In this paper, I propose an econometric technique to estimate a Markov‐switching Taylor rule subject to the zero lower bound of interest rates. I show that linking the switching of the Taylor rule coefficients to the switching of the coefficients of an auxiliary uncensored Markov‐switching regression improves the identification of an otherwise unidentifiable prevalent monetary regime because of the presence of the zero lower bound. Using a Markov‐switching fiscal policy rule as the auxiliary regression, I apply the estimation technique to U.S. data. Results show evidence of monetary and fiscal policy comovements, with monetary policy reacting weakly to inflation when fiscal policy is focused on real activity as opposed to debt stabilization, and vice versa.     

Simple Monetary Rules under Fiscal Dominance

This paper asks whether interest rate rules that respond aggressively to inflation, following the Taylor principle, are feasible in countries that suffer from fiscal dominance. We find that if interest rates are allowed to also respond to government debt, they can produce unique equilibria. But such equilibria are associated with extremely volatile inflation. The resulting frequent violations of the zero lower bound make such rules infeasible. Even within the set of feasible rules the welfare optimizing response to inflation is highly negative. The welfare gain from responding to government debt is minimal compared to the gain from eliminating fiscal dominance.     

Risk Premium Shocks and the Zero Bound on Nominal Interest Rates

Quantitative dynamic stochastic general equilibrium (DSGE) models often admit that the zero bound on nominal interest rates does not constrain (optimal) monetary policy. Recent economic events, however, have reinforced the relevance of the zero bound. This paper sheds some light on this disconnect by studying a broad range of shocks within a standard DSGE model. In contrast to earlier studies, we find that risk premium shocks are key to building quantitative models where the zero bound is relevant for monetary policy design. Other commonly included shocks, such as productivity, government spending, and money demand shocks, are unable to push nominal rates close to zero.     

Flexible inflation targeting and financial stability: Is it enough to stabilize inflation and output?

We investigate empirically whether a central bank can promote financial stability by stabilizing inflation and output, and whether additional stabilization of asset prices and credit growth would enhance financial stability in particular. We employ an econometric model of the Norwegian economy to investigate the performance of simple interest rate rules that allow a response to asset prices and credit growth, in addition to inflation and output. We find that output stabilization tends to improve financial stability. Additional stabilization of house prices, equity prices and/or credit growth enhances stability in both inflation and output, but has mixed effects on financial stability. In general, financial stability as measured by e.g., asset price volatility improves, while financial stability measured by indicators that depend directly on interest rates deteriorates, mainly because of higher interest rate volatility owing to a more active monetary policy.