Case: staggered treatments, homogenous (constant) TEs. (100 units, 15 time periods)

• "Cohort 1": 35 units are treated once at t=7, constant ATT(g=1,K)=49 for K=0-8 periods after the treatment (t=7-15)
• "Cohort 2": 35 units are treated once at t=11, constant ATT(g=2,K)=49 for K=0-4 periods after the treatment (t=11-15)
• 30 units are never treated

Case: staggered treatments, heterogenous (constant) TEs. (100 units, 15 time periods)

• "Cohort 1": 35 units are treated once at t=7, constant ATT(g=1,K)=20 for K=0-8 periods after the treatment (t=7-15)
• "Cohort 2": 35 units are treated once at t=11, constant ATT(g=2,K)=40 for K=0-4 periods after the treatment (t=11-15)
• 30 units are never treated
• TE estimates for K>4 periods post-treatment are non-sense b/c for the 2nd cohort, we only have data up to 4-periods post treatment, so estimates of ATT_K for K>4 only average out the TE for the first cohort (which has a smaller ATT=20)
• TWFE-OLS & CDLZ are biased.