“…These typically involve the use of principal components methods to extract the information in the large number of variables into a small number of factors thus avoiding over-parameterization concerns. Starting with Banbura, Giannone, and Reichlin (2010) many researchers have been simply including all the variables in a Vector Autoregression (VAR) and using Bayesian shrinkage priors to avoid over-fitting (see, among many others, Koop (2013), Giannone, Lenza, and Primiceri (2015), Jarocinski and Mackowiak (2017), Carriero, Clark, and Marcellino (2019), Koop and Korobilis (2019), Korobilis and Pettenuzzo (2019), Giannone, Lenza, and Primiceri (2019), Huber and Feldkircher (2019), Chan (2020) and Hauzenberger, Huber, and Onorante (2021)).…”