\(X\) may include some information related with \(R\). The function
extract factors from X which is not related with R by iteration
based on Boivin et al. (2009).
Usage
BGM(X, R, K = 2, tolerance = 0.001, nmax = 100)
Arguments
X
a large matrix from which principle components are extracted.
R
a numeric vector which we are interesting in, for example interest rates.
K
the number of extracted principle components.
tolerance
the difference between factors when iterating.
nmax
the max iterations, see details.
Value
the first K principle components, i.e. \(F_t^{(n)}\), not containing the information R.
Details
The algorithm is as follows:
Extract the first K principal components noted \(F_t^{(0)}\) from X.
Regress X on \(F_t^{(0)}\) and \(R_t\), and get regression
coefficients \(\beta_R^{(0)}\) of \(R_t\).
compute \(X_0^{(0)} = X_t- R_t \beta_R\).
Extract the first K principal components noted \(F_t^{(1)}\) from
X_t^{(0)}.
repeat step 2 - step 4 until precision you want.
References
Boivin, J., M.P. Giannoni and I. Mihov, Sticky Prices and Monetary Policy: Evidence
from Disaggregated US Data. American Economic Review, 2009. 99(1): p. 350-384.