“…Second, the common factor approach, typically estimated through Principal Components Analysis (PCA), models the variance structure of the financial variables using optimal linear combinations of them. Occasionally, other methods such as common factor analysis using a Kalman filter (Gumata et al, 2012) or semistructural models (Krznar and Matheson, 2017) are employed. The VAR approach has the advantage of linking financial conditions and GDP as the variable of ultimate interest in a system of equations but may present econometric challenges (most notably issues related to degrees of freedom), while the PCA allows for inclusion of ample financial variables, but is, by construction, agnostic about the relationship to output (Ho and Lu, 2013) 2 despite having been found to predict future growth well and occasionally outperforming leading indicators (Gumata et al, 2012).…”