Stochastic Volatility in Bayesian Vector Autoregressions
Stochastic Volatility in Bayesian Vector Autoregressions
- Todd E. ClarkTodd E. ClarkResearch, Federal Reserve Bank of Cleveland
- , and Elmar MertensElmar MertensResearch, Deutsche Bundesbank
Summary
Vector autoregressions with stochastic volatility (SV) are widely used in macroeconomic forecasting and structural inference. The SV component of the model conveniently allows for time variation in the variance-covariance matrix of the model’s forecast errors. In turn, that feature of the model generates time variation in predictive densities. The models are most commonly estimated with Bayesian methods, most typically Markov chain Monte Carlo methods, such as Gibbs sampling. Equation-by-equation methods developed since 2018 enable the estimation of models with large variable sets at much lower computational cost than the standard approach of estimating the model as a system of equations. The Bayesian framework also facilitates the accommodation of mixed frequency data, non-Gaussian error distributions, and nonparametric specifications. With advances made in the 21st century, researchers are also addressing some of the framework’s outstanding challenges, particularly the dependence of estimates on the ordering of variables in the model and reliable estimation of the marginal likelihood, which is the fundamental measure of model fit in Bayesian methods.
Subjects
- Econometrics, Experimental and Quantitative Methods
- Macroeconomics and Monetary Economics