Politicians and anecdotal evidence – a natural fit

OPINION: Evidence comes in all shapes and sizes – indeed in these days of Trumpism is seems evidence can be whatever you want it to be (the – “it feels like it ought to be true so it must be”-  school of thought).  Most politicians have a special affinity for anecdotal evidence.  The distinguishing characteristics of this type of evidence is that it is based on the experience of a small number of people, is rarely quantitative, is often accompanied by an interesting story and may or may not have any relationship to the structured observational evidence on the same subject.

The latest foray into this area was from Bill English who asserted that young New Zealanders were not getting jobs that were going to immigrants because they were failing or avoiding drug tests.  This was based on conversations with some farmers most probably.   There was nothing to say that the anecdotes were subsistent with the bulk of the evidence, although some other anecdotes emerged that seemed to support the basis argument.  And then evidence (real evidence became available from the Drug Foundation and I think the showed that only 0.17% of young working aspirants failed drug tests.  That is a minuscule number.

However, by now the story had legs and that was that.

Politicians love anecdotal evidence except perhaps those earnest individuals on the right. Basically, anecdotes are easy to find and use, you can generally find one to match whatever argument you want to make, they often have a human-interest perspective which adds interest and they are difficult to refute.

But sometimes anecdotal evidence is all you have and it is a case of use it or have nothing.  Much of my career was spent in the science and technology area and that so one of the areas where there is considerable reliance on evidential anecdote.  Anecdotes usually relate to specific types of situation and/or specific organisations such as companies.  They appear in S&T because is it genuinely hard and expensive to get good quality quantitative evidence about performance in the broad – most analysts give it up as too hard, although it is possible.  There is a suspicion that analysts do not try too hard because they are nervous about the possible results.

Anecdotal evidence can be made more “respectable” if it relates to a series of anecdotes which describe related but different situations.  The more the background that can be given the more that meaning can be extracted.

But none of that is likely to influence the use of anecdotes in politics.

By Bas Walker

This is another of Bas‘s posts on GrownUps.  Check out for his articles here, containing his Beachside Ponderings.