قارن الطرق

	اختبار جذر الوحدة المعزز لديكي-فولر (ADF)	اختبار DF-GLS: اختبار جذر الوحدة لديكى-فولر المنزوع الاتجاه بواسطة GLS
المجال	الاقتصاد القياسي	الاقتصاد القياسي
العائلة	Regression model	Hypothesis test
سنة النشأة	1979	1996
صاحب الطريقة	David A. Dickey & Wayne A. Fuller	Elliott, Rothenberg & Stock
النوع	Unit-root test for stationarity	One-sided t-test on GLS-detrended series
المصدر التأسيسي	Dickey, D. A., & Fuller, W. A. (1979). Distribution of the estimators for autoregressive time series with a unit root. Journal of the American Statistical Association, 74(366a), 427–431.	Elliott, G., Rothenberg, T. J., & Stock, J. H. (1996). Efficient tests for an autoregressive unit root. Econometrica, 64(4), 813–836.
الأسماء البديلة	ADF test, Dickey-Fuller test, unit root test, Genişletilmiş Dickey-Fuller testi	Elliott-Rothenberg-Stock test, ERS unit-root test, GLS-detrended Dickey-Fuller test, DF-GLS birim kök testi
ذات صلة	4	3
الملخص	The Augmented Dickey-Fuller (ADF) test is the most widely used test for a unit root — that is, for whether a time series is non-stationary and must be differenced before modelling. Introduced by David Dickey and Wayne Fuller in 1979 and extended by Said and Dickey in 1984 to series with higher-order autocorrelation, it regresses the change in the series on its lagged level plus lagged differences and asks whether the lagged-level coefficient is zero.	The DF-GLS test, introduced by Elliott, Rothenberg, and Stock (1996), is a modified augmented Dickey-Fuller procedure that applies generalized least squares (GLS) detrending before the standard unit-root regression. By removing deterministic components under a local alternative rather than the null hypothesis, the test achieves near-optimal power for detecting stationarity in time series, making it the preferred unit-root test in applied econometrics when a trend or intercept is present.