When Decisions Must be Based on Partial Causal Knowledge: Analyzing Causality and Evidence for Health Policy

Abstract

Public health decisions are needed even if the available knowledge about causes and effects is sometimes incomplete. We define four scenarios which describe four possible instances of incomplete causal knowledge in the context of public health decision-making. First, the evidential gap might be small, with a reasonable amount of causal evidence pointing to the same causal conclusion. Second, there might be only limited, isolated causal evidence available for public scrutiny, and yet decisions might be necessary despite of the big evidential gap. Third, causal knowledge might be incomplete in the sense that, within an extensive body of evidence, different types of evidence point to diverging causal conclusions. Fourth, in case of health emergencies, incomplete causal knowledge might derive from the impossibility of producing the necessary evidence through the established standards and procedures. For each of these scenarios, we consider the interplay between empirical evidence, philosophical basic implicit assumptions in science (philosophical bias) about causality, and ethical considerations. Although philosophical biases about causality and ethics have ubiquitous roles in evidence-based decision making, we argue that their identification and discussion is particularly relevant in the last two scenarios. We conclude with an argument in favour of cultivating conceptual diversity about causality among scientists and decision makers. This, we maintain, can help to build resilience for health emergencies.