By Sven Ove Hansson and Gertrude Hirsch Hadorn
Scientific uncertainty creates problems in many fields of public policy. Often, it is not possible to satisfy the high demands on the information input for standard methods of policy analysis such as risk analysis or cost-benefit analysis. For instance, this seems to be the case for long-term projections of regional trends in extreme weather and their impacts.
However, we cannot wait until science knows the probabilities and expected values for each of the policy options. Decision-makers often have good reason to act although such information is missing. Uncertainty does not diminish the need for policy advice to help them determine which option it would be best to go for.
When traditional methods are insufficient or inapplicable, argument-based tools for decision analysis can be applied. Such tools have been developed in philosophy and argumentation theory. They provide decision support on a systematic methodological basis. These tools enable a systematic decision analysis when the high demands on the information input of standard methods such as risk analysis or cost-benefit analysis are not fulfilled.
Reasoning with argument-based tools
An argument consists of an inference from one or several premises to a conclusion. Argument analysis scrutinizes whether or to what extent the conclusion is supported by the premises. To this end, argument analysis identifies the positions in a debate as well as the range of possible reasons that may speak for or against these positions. It furthermore reconstructs reasons and positions as inferences from premises to conclusions and assesses whether inferences are correct.
Argument-based tools for decision analysis
The concept of argument analysis is wide and covers a large and open-ended range of methods and tools, including tools for conceptual analysis, structuring decisions, assessing arguments, and evaluating decision options.
Argument-based tools can be used to systematize deliberations if, for instance, probabilities or values are undetermined or further information is lacking, uncertain or contested. This can, for instance, apply to information about what options are available or how to frame those options and what their potential consequences may be. See the figure below for an overview of argument-based tools to assess uncertainty of components in a decision.
The argumentative turn in policy analysis is a widened rationality approach that scrutinises inferences from what is known and what is unknown in order to support decision-supporting deliberations. It includes and recognises the normative components of decisions and makes them explicit in order to help in finding reasonable decisions with democratic legitimacy. Such legitimacy has to be grounded in a social framework that assigns a large role to rational argumentation.
To find out more:
Hansson, Sven Ove and Hirsch Hadorn, Gertrude (eds). (2016). The Argumentative Turn in Policy Analysis – Reasoning about Uncertainty. Springer: Cham, Switzerland. Online (DOI): 10.1007/978-3-319-30549-3
This book, written by an international team of philosophers, is the first comprehensive presentation of argument-based methods for decision analysis. It contains case studies including decisions on flood risk governance, decisions taken in the course of the financial crisis in 2008, uncertainty assessment for deciding on cleaning up a nuclear waste site, research about climate geoengineering and research in the field of synthetic biology that will become policy problems in the future.
Biography: Sven Ove Hansson is professor in philosophy at the Department of Philosophy and History, Royal Institute of Technology, Stockholm. He is editor-in-chief of Theoria and member of the Royal Swedish Academy of Engineering Sciences. His research includes contributions to decision theory, the philosophy of risk, moral and political philosophy, logic, and the philosophy of science and technology.
Biography: Gertrude Hirsch Hadorn is an adjunct professor at the Department of Environmental Systems Science, ETH Zurich. She has worked in environmental ethics and in the philosophy of environmental and sustainability research with case studies in the fields of climate change and ecology. She has contributed to the methodology of transdisciplinary research, the analysis of values in science, the epistemology of computer simulations, and the analysis of uncertainty and decision-making.