Editing Point estimation (section)

=== Best linear unbiased estimator (BLUE) ===
[[Best linear unbiased estimator]], also known as the Gauss–Markov theorem states that the ordinary least squares (OLS) estimator has the lowest sampling variance within the class of linear unbiased estimators, if the errors in the linear regression model are uncorrelated, have equal variances and expectation value of zero.<ref>{{Cite book|title=Best Linear Unbiased Estimation and Prediction|publisher=Theil Henri|year=1971|location=New York: John Wiley & Sons}}</ref>