手法を比較

	ロバスト加重最小二乗法 (Robust WLS)	加重最小二乗法 (WLS)
分野	計量経済学	統計学
系統	Regression model	Regression model
提唱年	1964/1981	1935
提唱者	Huber, P. J.	Alexander Craig Aitken
種類	Robust weighted regression	Weighted linear estimator
原典	Huber, P. J. (1981). Robust Statistics. Wiley. ISBN: 978-0471418054	Aitken, A. C. (1935). IV.—On least squares and linear combination of observations. Proceedings of the Royal Society of Edinburgh, 55, 42–48.
別名	robust weighted least squares, RWLS, heteroscedasticity-robust WLS, outlier-robust weighted regression	WLS, weighted regression, heteroscedasticity-corrected OLS, variance-weighted least squares
関連	5	3
概要	Robust WLS combines weighted least squares — which corrects for known or estimated heteroscedasticity — with robust M-estimation that down-weights influential outliers. The result is a regression estimator that is simultaneously efficient under non-constant error variance and resistant to observations that would otherwise distort coefficient estimates.	Weighted Least Squares is a generalization of Ordinary Least Squares (OLS) regression that assigns each observation a weight inversely proportional to its error variance, thereby down-weighting high-variance data points and up-weighting precise ones. Introduced in its general matrix form by Alexander Craig Aitken in 1935, WLS is the canonical remedy when heteroscedasticity is present and the error variance structure is known or can be reliably estimated.