4.27 ATT: Average Effect of the Treatment on the Treated and the Control
- ATE is often defined for subgroups (See types of treatment effects)
- One subgroup are those exposed to the treatment.. the treated
- Average Effect of Treatment on Treated (ATT): E[Yi1 - Yi0 | Di = 1]
- Q: Which observations does that concern in our table?
- Q: Why might we sometimes be interested in the ATT instead of the ATE? Think of real examples!