On Well-defined Hypothetical Interventions in the Potential Outcomes Framework

To the Editor: A recent series of articles, commentaries, letters, and responses across numerous journals1–12 has considered the role and limits of the potential outcomes framework within the broader undertaking of causal inference. In one response in that exchange, Broadbent et al7 noted that the potential outcomes framework often makes reference to the notion of a “hypothetical intervention” but typically without formal explication of what...