Σύγκριση μεθόδων

	Εκτιμητής GMM Διαφορών (Arellano-Bond)	Μοντέλο Δυναμικών Δεδομένων Πάνελ
Πεδίο	Οικονομετρία	Οικονομετρία
Οικογένεια	Regression model	Regression model
Έτος προέλευσης	1991	1988–1991
Δημιουργός	Manuel Arellano and Stephen Bond	Arellano & Bond (1991); Holtz-Eakin, Newey & Rosen (1988)
Τύπος	GMM panel estimator	Dynamic regression / GMM estimation
Θεμελιώδης πηγή	Arellano, M., & Bond, S. (1991). Some tests of specification for panel data: Monte Carlo evidence and an application to employment equations. Review of Economic Studies, 58(2), 277–297.	Arellano, M., & Bond, S. (1991). Some tests of specification for panel data: Monte Carlo evidence and an application to employment equations. Review of Economic Studies, 58(2), 277–297.
Εναλλακτικές ονομασίες	Arellano-Bond estimator, AB-GMM, first-difference GMM, difference GMM estimator	dynamic panel model, panel data model with lagged dependent variable, DPD model, Arellano-Bond model
Συναφείς	5	5
Σύνοψη	Difference GMM, introduced by Arellano and Bond (1991), estimates dynamic panel data models by first-differencing the equation to remove fixed effects, then using lagged levels of the endogenous variables as GMM instruments. It is the standard approach when a lagged dependent variable or other endogenous regressors are present in a panel with many units and few time periods.	The dynamic panel data model extends standard panel regression by including a lagged value of the outcome variable as a regressor, capturing persistence and adjustment dynamics. Because the lagged dependent variable is correlated with the unit-specific fixed effect, ordinary OLS or within estimators are biased; GMM-based methods using internal instruments are the standard remedy.