From CBA to decision trees and cognitive maps: Supplementing costs and benefits to acknowledge uncertainties and complexity in decision making

Abstract

Decision making has always been di¿cult due to uncertainty about the future, but humans invented strategies to overcome these di¿culties. Climate change, however, has brought new challenges: on the one hand, many of these strategies have become inappropriate to face impacts of climate change; on the other hand, climate change is extensive which needs a response from everyone, everywhere, at every moment in time. This thesis takes the cost and bene¿t framework as a starting point to show if and how divulging uncertainties and complexities may improve decision-making and project evaluations that are done prior to investments. Overall, the work undertaken here demonstrates that improving decision-making based on costs and bene¿ts is both necessary and feasible. The cost-bene¿t model may bene¿t from being used together with (semi-) qualitative and illustrative methodologies that are better suited to communicate on complexities underlying decision-making and that enable to understand and acknowledge model assumptions. Illustrating complexities may result insightful and complementary. Using the bene¿t-cost model together with other more appropriate evaluation methods may also be more desirable in order to avoid reproducing from the past, what may not be suited for the future. In order to achieve this, economic assessments need also include the participation of actors from di¿erent backgrounds to expose knowledge that would otherwise remain hidden, while valuing democratic participation. Including interactions across various research domains and participants may enable to visualise and highlight the inter-linkages between domains and their complexity, instead of inhibiting what is the very nature of interactions of societies with their environment. This may enable to identify the root causes of vulnerabilities and a more complete range of interventions. This work is anticipated to be a starting point for more sophisticated applications, more participative and interlinked evaluation methods that use several methodologies. In addition, future research can build on di¿erent insights provided by neuroscientists and psychologists. Sound decision-making may not come from methodologies alone, but from humans¿ physical capacity to develop and implement them.