قارن الطرق

	المربعات الصغرى العادية (OLS) مع أخطاء معيارية قوية	نموذج التأثيرات الثابتة للبيانات المقطعية الزمنية (Panel Fixed Effects Model)
المجال	الاقتصاد القياسي	الاقتصاد القياسي
العائلة	Regression model	Regression model
سنة النشأة	1980	1978
صاحب الطريقة	Halbert White	Mundlak (1978); classical treatment in Wooldridge (2010) and Baltagi (2021)
النوع	Linear regression with robust inference	Panel regression estimator
المصدر التأسيسي	White, H. (1980). A heteroskedasticity-consistent covariance matrix estimator and a direct test for heteroskedasticity. Econometrica, 48(4), 817–838.	Wooldridge, J. M. (2010). Econometric Analysis of Cross Section and Panel Data (2nd ed.). MIT Press. ISBN: 978-0262232586
الأسماء البديلة	HC robust regression, White robust OLS, sandwich estimator OLS, OLS with robust standard errors	within estimator, FE model, within-group estimator, LSDV model
ذات صلة	6	5
الملخص	Robust OLS applies ordinary least squares to estimate coefficients and then replaces the classical standard errors with heteroscedasticity-consistent (HC) standard errors — commonly called White standard errors. This leaves the point estimates unchanged while yielding valid t-statistics and confidence intervals even when the error variance is not constant across observations.	The panel fixed effects (FE) model controls for all time-invariant, unit-specific unobserved heterogeneity by absorbing it into individual intercepts. By sweeping out unit means through the within transformation, FE yields unbiased estimates of the effect of time-varying regressors even when omitted unit-level confounders are correlated with those regressors.