How do I estimate the Average Treatment Effect on the Treated in a Difference-In-Difference Model? Suppose the DID model is
Y = a + b(Treatment) +c(Time) + d(Treatment*Time). Now, If i wanted to find out the average treatment effect on the treated, how should i modify my model?

DID estimates the ATT. If treatment was randomized, then ATT=ATE=ATU.
