What is the added value of expert groups for decision making?

In this paper, we raise the question of the usefulness of expert groups or scientific councils like those that were created during the COVID-19 crisis in several countries. We begin by characterising expertise and the limits of experts' knowledge. Then, we recall why expertise is not decision-making. In the third part we review the weaknesses of group thinking and the role of responsibility and commitment in decision-making. The fourth part is devoted to learning and we finally conclude on the usefulness of using expert knowledge and/or expert group knowledge, depending on the situation and on your aim but certainly not inducting experts as decision makers.