4.24 Assumptions: SUTVA
- SUTVA: Stable Unit Treatment Values Assumption
- -1- No interference & -2- No hidden variations of treatment
- The potential outcomes for any unit do not vary with the treatments assigned to other units
- A subject’s potential outcome is not affected by other subjects’ exposure to the treatment
- For each unit, there are no different forms or versions of each treatment level, which lead to different potential outcomes (Consistency) (Imbens and Rubin 2015, 10; Keele 2015b, 5)
- Q: Imagine you all have a headache (Pain = Yes) and we try to randomly assign aspirin to one half of you to test its effect: What would the two assumptions (No interference, No hidden variations) mean in that situation? Discuss with your neighbour!
Imbens, Guido W, and Donald B Rubin. 2015. Causal Inference for Statistics, Social, and Biomedical Sciences: An Introduction. Cambridge University Press.
Keele, Luke. 2015b. “The Statistics of Causal Inference: A View from Political Methodology.” Polit. Anal. 23 (3): 313–35.