New “Risk and Decisions” Course – Center for Health Decision Science

Determining whether and how to control environmental hazards raises many challenging questions related to understanding the risks and the benefits and costs of controls. In this new intensive course (EH 550), students will delve into the interface between risk assessment and policy, exploring evidence from epidemiology and toxicology and approaches for economic evaluation.

The course will be held in January 2025. It will be led by John S. Evans, accompanied by CHDS Deputy Director Lisa A. Robinson. Evans recently retired from his position as Adjunct Professor of Environmental Health in the Harvard Chan School Department of Environmental Health, and was a founding member of the Harvard Center for Risk Analysis.

The course asks each student to consider how they would decide which environmental exposures pose risks so large that they must be controlled, and which are so small that they may safely be ignored. For those which must be controlled, it asks them to develop an approach for deciding how much control is necessary and how to distinguish circumstances where they must act now from those where uncertainty is so large that control decisions should be deferred (to allow researchers time to conduct studies intended to improve understanding of the risks involved). The distinction between positive analysis (describing what “is,” amenable to research) and normative analysis (requiring ethical or moral value judgements) is discussed. We consider the complexity introduced when individual preferences (health vs. wealth, risk neutrality-aversion-proneness) differ substantially across the affected population.

The course examines the interpretation of evidence from epidemiology and toxicology in risk assessment. It considers the sources of uncertainty inherent in estimates of reference doses and cancer potencies derived from animal studies, in vitro analyses and structure-activity relationships, and effect estimates from epidemiological studies and introduces approaches for characterization and analysis of the propagation of uncertainty. The course then introduces the concepts and framework of economic evaluation; reviews various approaches for valuing risks to health and longevity; and discusses methods for incorporating consideration of the distribution and equity of control costs and health benefits. With this knowledge in hand, we explore the impact of uncertainty on decisions, both about emissions control and about research needs.

We seek a set of principles, solidly grounded in theory, and a toolbox of approaches for applying these principles, which will support more informed decision making about environmental controls.

Learn more: Read the Risk Analysis article, Introduction to Special Issue on Risk Assessment, Economic Evaluation, and Decisions