Implements the two-step GMM estimator of He, Huang, Li, and Zhou (2023).
Factor proxies X are rotated to maximise explanatory power for the
target return matrix target, using diagonal GMM weighting matrices.
Arguments
- target
Numeric matrix (T x N) of target variables (e.g., asset returns). A vector is coerced to a T x 1 matrix.
- X
Numeric matrix or data frame (T x L) of factor proxies.
- nfac
Positive integer; number of RRA factors to extract.
- compute_stat
Logical; if
TRUE, compute the GMM J-test statistic for overidentifying restrictions. Returned asNULLwhenFALSE(default) or when degrees of freedom <= 0.
References
He, J., Huang, J., Li, F., and Zhou, G. (2023). Shrinking Factor Dimension: A Reduced-Rank Approach. Management Science, 69(9). doi:10.1287/mnsc.2022.4563
