Plea for acknowledgement of uncertainties in policy-guiding models: “No one model can serve all purposes”

22 experts from several disciplines have raised concerns about the use of opaque, spuriously precise models to guide policies in matters as complex as the current Covid-19 pandemic. In a comment published today in Nature, they argue that models that discount uncertainties might undermine social trust in science and convey a false sense of predictability, thus leading to potentially harmful consequences if the model-based inferences are used to guide policies in the real, uncertain world.

As Jeroen van der Sluijs, professor at the Copernicus Institute for Sustainable Development of Utrecht University, puts it: “Results from models will at least partly reflect the interests, disciplinary orientations and biases of the developers. No one model can serve all purposes: the technique is never neutral.”

Proposing practices

The authors have proposed a set of practices to increase the transparency and capacity of models to provide useful insights for policy-making. These guidelines combine statistical approaches with social norms that should be observed throughout the continuum that goes from model design to the effective implementation of model-based policies.

The group argues that models should make their assumptions explicit, systematically account for uncertainties, tame model hubris and acknowledge model limitations. Multiple views on the issue of interest should be integrated, and stakeholders involved, to preserve complexity.

They also ask modelers to acknowledge ignorance, a much needed virtue to prevent model end-users from making excessively adventurous claims on issues that might not have a clearcut fix.

New social norms

First author Andrea Saltelli, Professor at the Center for the Sciences and the Humanities, University of Bergen: “Modellers, decision makers and citizens need to establish new social norms such that modellers are not permitted to project more certainty than their models deserve, and politicians are not allowed to offload accountability to models of their choosing.”

Publication: Andrea Saltelli et al., 2020, Five ways to ensure that models serve society: a manifesto. Nature Comment.