Models should make policy-making honest

In the last issue we covered a new report by Yaron Hollander, a former Transport for London modelling manager, looking at ten misuses of transport models. This is one of a selection of responses from within the modelling community

Professor John Polak

27 November 2015

Professor John Polak is director of the Urban Systems Laboratory, chairman of the Centre for Transport Studies, and director of research in the Department of Civil and Environmental Engineering at Imperial College London.

I think there are two distinct threads to Yaron’s comments, which it is easy to confuse but which should be considered separately; the first that models are imperfect and second that models can be misused. Even a perfect model could be egregiously misused, as a result of incompetence or malice or both, so the distinction is rather important.

On the first point, we must recognise that models will always be imperfect and while we should of course try to improve them we should be humble and...