Beyond Marginal Recovery: Weighing Benefit and Harm at the Bedside and in Policy

Abstract

We thank Dawid and Senn (2026) for clarifying why marginal interventional probabilities suffice when the objective is to maximize average recovery. We argue that the debate over counterfactuals in personalized decision-making persists because it conflates two levels of decision-making: individual bedside consultations and population policymaking. In a bedside consultation, a patient may be averse to treatment-caused harm relative to standard care, and the clinician’s role is to combine marginal study evidence with consultation-specific context to calibrate a subjective belief about joint potential outcomes. At the population level, a policymaker relies on marginal recovery rates conditional on measured study covariates, leaving counterfactual harm only partially identified. Using a three-arm extension of Dawid and Senn (2026), we characterize when marginal evidence suffices to uniquely determine an optimal treatment under harm aversion, when it yields a partial order that eliminates inferior options while leaving non-dominated treatments for clinical consultation, and how population harm budgets induce priority rules via lexical leapfrogging.