‘Risk’ is an emotive word, it immediately conjures up danger, and an instinctive reluctance to avoid it, if at all possible.
Relative risk is often used in a selling situation as a means to motivate the potential buyer to take that last step, and buy, immediately. The risk may be of missing out, of a price rise, or of an unpleasant event happening, and many other things that might incite a sense of urgency. Unless you apply some added, and not usually made available logic, you can be seduced by the size of the stated risk, and buy, when it may not be a logically consistent decision to do so.
When you see the word ‘Risk’ in a brochure, offering research numbers that demonstrate how much this new ‘whizzo’, newly developed after much research, will reduce your risk, do not take them at face value.
For example, if I was selling a new medication aimed at older fathers, of which there is an increasing number, I might use something like the copy following.
‘For men of 50 fathering children, there is an 18% greater chance of those children suffering seizures, than children of a father of 30′. New ABC medication from XYZ company can more than halve this risk’
This first part of this copy would be alarming to any man in this group, but misleading. It is a relative risk, comparing one group to another. It does not tell you how likely it is that an individual child will have a seizure, which is an absolute risk. The second part, promises a huge reduction in this risk as an inducement to buy, but again, very misleading, because the reduction in risk is relative.
Had the copy been complete, it would also have told the reader:
The child of a father aged 30 has a risk of seizure of .024%, 24 out of 100,000 children.
The child of a father aged 50 has a risk of seizure of .028%, 28 out of 100,000 children.
(Data source new scientist November 2018)
An increase of 18% to the risk of children of fathers over 50 suffering seizures, compared to that of fathers of 30 sounds shocking, but when you consider it is 4 children in 100,000, it is less so. Equally, the reduction coming from new ABC medication is less impressive when viewed as an absolute reduction, from 4 to 2, and the (poor) statistician in me tells me it is within the boundaries of statistical error in any event.
Daniel Kahneman in his great book ‘Thinking Fast & Slow’ uses a number of examples similar to the one above, and in addition would apply the question: ‘How much would you pay to reduce the risk of your child having seizures from 4/100,000 to 2/100,000’? to get a better measure of the price difference between a purely rational decision, and an emotional one.
Emotion sells way, way better than rationality, so the usual way to present data will almost inevitably be relative. Watch out for it, and ask the appropriate questions before you jump to a purchase decision.
Header cartoon courtesy of Scott Adams and ‘Dilbert’ https://dilbert.com/
