Home About Latest Browse RSS Advanced Search

Federal Reserve Bank of New York
Staff Reports
Identifying shocks via time-varying volatility
Daniel J. Lewis
Abstract

An n-variable structural vector auto-regression (SVAR) can be identified (up to shock order) from the evolution of the residual covariance across time if the structural shocks exhibit heteroskedasticity (Rigobon (2003), Sentana and Fiorentini (2001)). However, the path of residual covariances is available only under specific parametric assumptions on the variance process. I propose a new identification argument that identifies the SVAR up to shock orderings using the autocovariance structure of second moments of the residuals implied by an arbitrary stochastic process for the shock variances. These higher moments are available without parametric assumptions like those required by existing approaches. I offer intuitive criteria to select among shock orderings; this selection does not impact inference asymptotically. The identification scheme performs well in simulations. I apply it to the debate on fiscal multipliers. I obtain estimates that are lower than those of Blanchard and Perotti (2002) and Mertens and Ravn (2014), but in line with those of more recent studies.


Download Full text
Cite this item
Daniel J. Lewis, Identifying shocks via time-varying volatility, Federal Reserve Bank of New York, Staff Reports 871, 01 Oct 2018.
More from this series
JEL Classification:
Subject headings:
Keywords: identification; impulse response function; structural shocks; SVAR; fiscal multiplier; time-varying volatility; heteroskedasticity
For corrections, contact Amy Farber ()
Fed-in-Print is the central catalog of publications within the Federal Reserve System. It is managed and hosted by the Economic Research Division, Federal Reserve Bank of St. Louis.

Privacy Legal