Σύγκριση μεθόδων

	Δεδομένα Πάνελ με Ενδογενείς Μεταβλητές (Panel IV / 2SLS)	Difference-in-Differences (Diff-in-Diff)
Πεδίο	Αιτιακή Συμπερασματολογία	Οικονομετρία
Οικογένεια	Regression model	Regression model
Έτος προέλευσης	1978-1991	1994
Δημιουργός	Hausman (1978); Anderson & Hsiao (1982); Arellano & Bond (1991)	Card & Krueger (canonical 1994 application); Angrist & Pischke (textbook treatment)
Τύπος	Causal inference / panel regression	Causal inference / panel regression
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.	Angrist, J. D., & Pischke, J.-S. (2009). Mostly Harmless Econometrics: An Empiricist's Companion. Princeton University Press. ISBN: 978-0691120355
Εναλλακτικές ονομασίες	Panel IV, Panel 2SLS, Within-IV, Fixed-Effects IV	diff-in-diff, DiD, Farkların Farkı (Diff-in-Diff)
Συναφείς	4	5
Σύνοψη	Panel data instrumental variables combines the bias-correcting power of instrumental variables (IV) with the within-unit variation exploited by panel data methods. It addresses endogeneity — omitted variables, reverse causation, or measurement error — in longitudinal settings where observations are repeated across units and time. Seminal contributions come from Hausman (1978) on specification testing and Arellano and Bond (1991) on GMM-based panel IV.	Difference-in-Differences is a causal-inference method that estimates the effect of an intervention by comparing how a treatment group and a control group change over time. Made famous by Card and Krueger's 1994 minimum-wage study and developed in Angrist and Pischke's Mostly Harmless Econometrics, it isolates the treatment effect as the difference between the two groups' before-after changes.