Variance, Covariance Matrix, Linear Regression, Standard Error, Confidence Interval.
model are mean independent: E(ϵ|X)=0 Linear form: The regression model has a linear form: y = Xβ + ϵ Residual errors e of the fitted model are unbiased estimates of the error terms ϵ. Homoskedastic errors: The model’s errors are homoskedastic: E(ϵ_i*ϵ_j|X) = σ² (a constant) when i = j, and,