Linganisha mbinu

	Tofauti-katika-Tofauti za Athari Tofauti za Matibabu (HTE-DiD)	Data Difference-in-Differences ya Panel (Panel DiD / TWFE)
Nyanja	Uhitimisho wa Kisababishi	Uhitimisho wa Kisababishi
Familia	Regression model	Regression model
Mwaka wa asili	2021	1985–2004
Mwanzilishi	Callaway & Sant'Anna; Sun & Abraham	Ashenfelter & Card (1985); codified by Angrist & Pischke (2009); serial correlation critique by Bertrand, Duflo & Mullainathan (2004)
Aina	Causal inference / panel regression	Causal inference / panel regression
Chanzo asilia	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
Majina mbadala	HTE-DiD, heterogeneous DiD, CATT estimator, group-time ATT	Two-Way Fixed Effects DiD, TWFE, Panel DiD, Panel Diff-in-Diff
Zinazohusiana	4	4
Muhtasari	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.