Suppose we run an experiment and measure several possible independent variables after treatment. Which of the following best characterizes why this is a problem?
A) Independent variables measured after treatment may be affected by the treatment and may therefore soak up some of the treatment effect.
B) Including post-treatment variables will induce multicollinearity.
C) Post-treatment variables will not satisfy the inclusion condition.
D) Including post-treatment variables will cause imbalance in the treated and control groups.

Question

Quizplus · Accepted Answer

Independent variables measured after treatment may be affected by the treatment and may therefore soak up some of the treatment effect. This means that including post-treatment variables may lead to biased estimates of the treatment effect, as the effect of the treatment cannot be clearly separated from the effect of the post-treatment variables.

Suppose We Run an Experiment and Measure Several Possible Independent