If you have a sufficiently large random sample from the population, but do not know how treatment was assigned, what object will a confidence interval centered on the difference in average outcomes for the treated and control groups be describing?
A) ATE
B) ETT
C) Selection Bias
D) ETT + Selection Bias

Question

Quizplus · Accepted Answer

A confidence interval centered on the difference in average outcomes for the treated and control groups, without knowing how treatment was assigned, describes the Estimated Treatment Effect on the Treated (ETT) plus any Selection Bias. This is because without knowing the assignment mechanism, we cannot distinguish between the effect of the treatment itself and the effect of the factors that led to receiving the treatment.

If You Have a Sufficiently Large Random Sample from the Population