But as former United States Secretary of the Treasury, Robert Rubin, observed a few years ago, “almost all significant issues are enormously complex […] the very nature of reality is complexity and ambiguity”.1  Knowledge Since policymakers face substantial uncertainty, they should strive to base their decisions on expert knowledge.
This is crucial for acquiring a deep understanding of a subject, making informed decisions in a way that distinguishes the technical from the political and adjusting those decisions in the light of new evidence.