In the 9th week of the Introduction to Causal Inference online course, we cover difference-in-differences. Please post questions in the YouTube comments section.
Introduction to Causal Inference Course Website: causalcourse.com
0:00 Intro
0:50 Outline
1:14 Motivation
3:15 ATT Estimand
6:02 Overview of Differences-in-Differences
13:03 Time-Invariant Unobserved Confounding
14:40 Assumptions
24:28 Proof
27:48 Problems with Difference-in-Differences