Changes in the transmission of monetary policy: evidence from a time-varying factor-augmented VAR

This paper re-examines the evolution of the US monetary transmission mechanism using an empirical framework that incorporates substantially more information than the standard tri-variate VAR model used in most previous studies. In particular, we employ an extended version of a factor-augmented VAR, where we introduce time variation in the coefficients and stochastic volatilities in the variances of the shocks. Our formulation has two substantive advantages over earlier work: (i) the additional information summarised by the common factors that are extracted from a large panel of aggregate and disaggregate variables improves the identification of the monetary policy shocks since the factors capture more accurately the amount of information analysed by the monetary authority, (ii) we are able to estimate the time-varying effects of monetary policy surprises on macroeconomic aggregates and disaggregate prices and quantities of personal consumption expenditures. Our main results indicate that time variation is a dominant feature of key macroeconomic variables and their components. In analysing the temporal evolution of disaggregate dynamics, we uncover a considerable amount of heterogeneity in sectoral price responses which suggests that monetary policy actions exert an important, and potentially long-lasting, influence on relative prices in the US economy.