Search Results
Working Paper
Understanding Uncertainty Shocks and the Role of Black Swans
Economic uncertainty is a powerful force in the modern economy. Research shows that surges in uncertainty can trigger business cycles, bank runs and asset price fluctuations. But where do sudden surges in uncertainty come from? This paper provides a data-disciplined theory of belief formation that explains large fluctuations in uncertainty. It argues that people do not know the true distribution of macroeconomic outcomes. Like Bayesian econometricians, they estimate a distribution. Our main contribution is to explain why real-time estimation of distributions with non-normal tails results in ...
Working Paper
Employment, Wages and Optimal Monetary Policy
We study optimal monetary policy when the empirical evidence leaves the policymaker uncertain whether the true data-generating process is given by a model with sticky wages or a model with search and matching frictions in the labor market. Unless the policymaker is almost certain about the search and matching model being the correct data-generating process, the policymaker chooses to stabilize wage inflation at the expense of price inflation, a policy resembling the policy that is optimal in the sticky wage model, regardless of the true model. This finding reflects the greater sensitivity of ...
Working Paper
Optimal monetary policy under model uncertainty without commitment
This paper studies the design of optimal time-consistent monetary policy in an economy where the planner trusts its own model, while a representative household uses a set of alternative probability distributions governing the evolution of the exogenous state of the economy. In such environments, unlike in the original studies of time-consistent monetary policy, managing households' expectations becomes an active channel of optimal policymaking per se, a feature that the paternalistic government seeks to exploit. We adapt recursive methods in the spirit of Abreu, Pearce, and Stacchetti (1990) ...
Report
Real-time inflation forecasting in a changing world
This paper revisits the accuracy of inflation forecasting using activity and expectations variables. We apply Bayesian-model averaging across different regression specifications selected from a set of potential predictors that includes lagged values of inflation, a host of real activity data, term structure data, nominal data, and surveys. In this model average, we can entertain different channels of structural instability by incorporating stochastic breaks in the regression parameters of each individual specification within this average, allowing for breaks in the error variance of the ...
Working Paper
On Monetary Policy, Model Uncertainty, and Credibility
This paper studies the design of optimal time-consistent monetary policy in an economy where the planner and a representative household are faced with model uncertainty: While they are able to construct and agree on a reference model (probability distribution) governing the evolution of the exogenous state of the economy, a representative household has fragile beliefs and is averse to model uncertainty. In such environments, management of households' expectations becomes an active channel of optimal policymaking per se. A central banker who respects the fact that private sector models are ...
Working Paper
Growth and Welfare Gains from Financial Integration Under Model Uncertainty
We build a robustness (RB) version of the Obstfeld (1994) model to study the effects of financial integration on growth and welfare. Our model can account for the empirically observed heterogeneity in the relationship between growth and volatility for different countries. The calibrated model shows that financial integration leads to significantly larger gains in growth and welfare for advanced countries than developing countries, with some developing countries experiencing growth and welfare loss in financial integration. Our analytical solutions help uncover the key mechanisms by which this ...
Discussion Paper
Choosing the Right Policy in Real Time (Why That’s Not Easy)
As an economist, you make policy recommendations at any point in time that depend on what model of the economy you have in mind and on your assessment of the state of the economy. One can see these points play out in the current discussion about the timing of interest rate liftoff and the speed of the subsequent renormalization. If you think nominal rigidities are not all that important, you are likely to conclude that accommodative policies won’t do much for growth but will generate inflation. Similarly, if you are convinced that the economy is already firing on all cylinders, you may see ...
Working Paper
On Model Aggregation and Forecast Combination
Policy makers express their views and decisions via the lens of a particular model or theory. But since any model is a highly stylized representation of the unknowable object of interest, all these models are inherently misspecified, and the resulting ambiguity injects uncertainty in the decision-making process. We argue that entropy-based aggregation is a convenient device to confront this uncertainty and summarize relevant information from a set of candidate models and forecasts. The proposed aggregation tends to robustify the decision-making process to various sources of risks and ...
Journal Article
Model Uncertainty and Policy Design
This article illustrates the main challenges and forces that emerge in optimal policy design when there are doubts about the probability model of uncertainty. Model doubts can stem from either the side of the public or the side of the policymaker, and they can give rise to cautious probabilistic assessments. A basic idea that surfaces in setups with model uncertainty is the management of the public's pessimistic expectations by the policymaker. The article also presents several implications of this idea.