In defence of Sage’s models

As a member of Sage, I support public scrutiny of our scientific advice. However, once our models enter the public domain they are interpreted in many different ways and some of the crucial context can be lost.

Modelling is an important tool for epidemic management, one that has been tested against numerous infectious disease outbreaks and continues to be improved. If we knew what the future held, decisions would be easy — but we don’t know what will happen. The alternative to using models is to guess. Models mean that the assumptions and data used are clear. It’s repeatable science. Guessing is not repeatable and relies on prejudices and wishful thinking, and changes from day to day. Nobody wants government policy to be based on guessing.

The critical problem for decision-making is that the future is unpredictable — models cannot predict numbers accurately. This is mostly because of behaviour that is often completely unpredictable.