Σύγκριση μεθόδων

	Διαφορές-σε-Διαφορές Ετερογενούς Επίδρασης Θεραπείας (HTE-DiD)	Διαχρονικά Δεδομένα Διαφορών σε Διαφορές (Panel DiD / TWFE)
Πεδίο	Αιτιακή Συμπερασματολογία	Αιτιακή Συμπερασματολογία
Οικογένεια	Regression model	Regression model
Έτος προέλευσης	2021	1985–2004
Δημιουργός	Callaway & Sant'Anna; Sun & Abraham	Ashenfelter & Card (1985); codified by Angrist & Pischke (2009); serial correlation critique by Bertrand, Duflo & Mullainathan (2004)
Τύπος	Causal inference / panel regression	Causal inference / panel regression
Θεμελιώδης πηγή	Callaway, B., & Sant'Anna, P. H. C. (2021). Difference-in-Differences with multiple time periods. Journal of Econometrics, 225(2), 200-230.	Angrist, J. D., & Pischke, J.-S. (2009). Mostly Harmless Econometrics: An Empiricist's Companion. Princeton University Press. ISBN: 978-0691120355
Εναλλακτικές ονομασίες	HTE-DiD, heterogeneous DiD, CATT estimator, group-time ATT	Two-Way Fixed Effects DiD, TWFE, Panel DiD, Panel Diff-in-Diff
Συναφείς	4	4
Σύνοψη	HTE-DiD extends the classic Difference-in-Differences estimator to settings where treatment effects vary across units, time periods, or treatment cohorts. Developed formally by Callaway and Sant'Anna (2021) and Sun and Abraham (2021), it avoids the biases that arise when a conventional two-way fixed-effects regression is used with staggered adoption or effect heterogeneity, by estimating cohort-and-time-specific average treatment effects that can then be aggregated flexibly.	Panel Data Difference-in-Differences extends the classic two-period DiD design to settings with multiple units observed across many time periods. By absorbing unit-level fixed effects and time fixed effects simultaneously, it isolates the causal effect of a treatment or policy change while controlling for both time-invariant unit heterogeneity and common time shocks affecting all units.