Regression Equations, Generalized Least Squares, Correlation Matrices, Python, Statsmodels.
the matrix Ω of correlation errors of the 8-model system by individually estimating the 8 models using OLS and using the fitted models’ residual errors as the proxy for the corresponding error terms ϵ_i. We’ll use the (Feasible) Generalized Least Squares (FGLS) estimator to estimate the entire