Effective Altruism’s Blind Spot:The Systematic Underestimation of Harm

Abstract

The rapid rise of effective altruism (EA) has reshaped contemporary global health and development by promoting the allocation of resources towards interventions that maximize measurable impact. While widely praised for its analytical rigour and commitment to evidence-based decision-making, EA has also attracted critique for its reliance on quantification, its technocratic orientation and its limited engagement with structural forms of inequality. This commentary builds on these debates but advances a more specific argument: that EA systematically underestimates negative unintended effects, resulting in an asymmetrical assessment of impact. We argue that this asymmetry reflects not only methodological biases—such as the preferential treatment of measurable outcomes— but also a deeper neglect of the distributional consequences of interventions. Framed throughthe guiding question, ‘effective for whom?’, the commentary examines two prominent EA-supported interventions—cash transfers and bed net distribution—to demonstrate how benefitsfor direct recipients may be accompanied by costs for non-recipients, local systems or public institutions. These costs are often diffuse, delayed or difficult to quantify, and therefore insufficiently incorporated into cost-effectiveness models. We propose three practical shifts: systematicallytracking non-recipient and system indicators, elevating qualitative and participatory evidence,and applying conservative downside adjustments when harms are plausible but hard to quantify.EA deserves a methodology that is capable of seeing the whole picture.