Our political system does not take evidence seriously. Below Tim Harford argues this is because of our love of certitude and our avoidence of uncertainty. The curse of uncertainty is that it makes everything feel unappealing.
It is not clear why we enjoy certitude so much – certitude being the subjective experience of feeling certain. In contrast – as Kathryn Schulz observes in her wonderful book Being Wrong – there is simply no psychological experience of “being wrong” at all, only the lurching realisation of having been wrong until a moment ago.
Manski argues that analysts should be far more open about the extent of their doubts, and that politicians can and should be able to cope. I am more pessimistic. Politicians are creatures of certitude: they join a tribe of like-minded people, convinced that the tribe on the other side is wicked and stupid. The media love certitude, too. Newspaper editors hate headlines with “may” or “might” in them.
For these reasons, the scholar who is honest about her doubts will find her work ignored in favour of some clever-sounding chap who just seems to know so much more about how the world works. (How else could he be so certain?) Brilliant scholars with strong, clear views, such as Milton Friedman, John Maynard Keynes and Paul Krugman, enjoy larger followings than brilliant scholars who deal in doubts and complications, such as Elinor Ostrom and Thomas Schelling.
Manski might seem quixotic in his request that serious policy analysis be presented with more humility, given that neither politicians nor the media have much appetite even for overly-certain serious policy analysis.
But there is a serious cost to excess certainty. Whenever an analyst or academic presents a number or a conclusion with too much precision, they reduce the demand for better evidence. Why run a pilot, set up a proper survey, if the answer is already known to three decimal places?