We study how Policymakers and business leaders alike saw the US economy between 2008 and 2014 as being buffeted by larger-than-usual uncertainty about fiscal policy. As illustrated by a number of prolonged struggles at all levels of government, there 1

This paper shows how changes in the volatility of the real interest rate at which small open emerging economies borrow have a quantitatively important e¤ect on real variables like output, consumption, investment, and hours worked. To motivate our investigation, we document the strong evidence of time-varying volatility in the real interest rates faced by a sample of four emerging small open economies: Argentina, Ecuador, Venezuela, and Brazil. We postulate a stochastic volatility process for real interest rates using T-bill rates and country spreads and estimate it with the help of the Particle …lter and Bayesian methods. Then, we feed the estimated stochastic volatility process for real interest rates in an otherwise standard small open economy business cycle model. We calibrate eight versions of our model to match basic aggregate observations, two versions for each of the four countries in our sample. We …nd that an increase in real interest rate volatility triggers a fall in output, consumption, investment, and hours worked, and a notable change in the current account of the economy.

a b s t r a c tIn this paper, we argue for the importance of explicitly considering nonlinearities in analyzing the behavior of the New Keynesian model with a zero lower bound (ZLB) of the nominal interest rate. To show this, we report how the decision rules and the equilibrium dynamics of the model are substantially affected by the nonlinear features brought about by the ZLB. We also illustrate a tension between the length of a spell at the ZLB and the drop in consumption there.

This paper shows how changes in the volatility of the real interest rate at which small open emerging economies borrow have a quantitatively important e¤ect on real variables like output, consumption, investment, and hours worked. To motivate our investigation, we document the strong evidence of time-varying volatility in the real interest rates faced by a sample of four emerging small open economies: Argentina, Ecuador, Venezuela, and Brazil. We postulate a stochastic volatility process for real interest rates using T-bill rates and country spreads and estimate it with the help of the Particle …lter and Bayesian methods. Then, we feed the estimated stochastic volatility process for real interest rates in an otherwise standard small open economy business cycle model. We calibrate eight versions of our model to match basic aggregate observations, two versions for each of the four countries in our sample. We …nd that an increase in real interest rate volatility triggers a fall in output, consumption, investment, and hours worked, and a notable change in the current account of the economy.

We study how Policymakers and business leaders alike saw the US economy between 2008 and 2014 as being buffeted by larger-than-usual uncertainty about fiscal policy. As illustrated by a number of prolonged struggles at all levels of government, there 1

This paper examines how supply-side policies may play a role in fighting a low aggregate demand that traps an economy at the zero lower bound (ZLB) of nominal interest rates. Future increases in productivity or reductions in mark-ups triggered by supply-side policies generate a wealth effect that pulls current consumption and output up. Since the economy is at the ZLB, increases in the interest rates do not undo this wealth effect, as we will have in the case outside the ZLB. We illustrate this mechanism with a simple two-period New Keynesian model. We discuss possible objections to this set of policies and the relation of supply-side policies with more conventional monetary and fiscal policies.

Motivated by the recent experience of the U.S. and the Eurozone, we describe the quantitative properties of a New Keynesian model with a zero lower bound (ZLB) on nominal interest rates, explicitly accounting for the nonlinearities that the bound brings. Besides showing how such a model can be e¢ ciently computed, we …nd that the behavior of the economy is substantially a¤ected by the presence of the ZLB. In particular, we document 1) the unconditional and conditional probabilities of hitting the ZLB; 2) the unconditional and conditional probabilty distributions of the duration of a spell at the ZLB; 3) the responses of output to government expenditure shocks at the ZLB, 4) the distribution of shocks that send the economy to the ZLB; and 5) the distribution of shocks that keep the economy at the ZLB.

We thank the NSF for financial support. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research. NBER working papers are circulated for discussion and comment purposes. They have not been peerreviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.