For pooled (CCEP) coefficients, computes the non-parametric VCE:
V_p = (1/N^2) sum_i (b_i - b_p)(b_i - b_p)'
This is the same formula as MG variance but applied to the deviation
from the pooled estimate rather than the MG estimate.
.pooled_vcov_pesaran(coef_list, b_pooled)Variance-covariance matrix.
List of unit-level coefficient vectors.
Numeric vector: the pooled coefficient.