David Robson
2nd August 2019

When you buy a cup of coffee, you might have noticed that of the three size options – small, medium and large – the medium-sized serving often costs almost as much as the large. Given the apparent bargain, have you ever opted for the biggest and most expensive option?
If so, you have been nudged by a cognitive bias known as the “decoy effect”, in which the deliberate presentation of an additional, slightly less attractive option – in this case, the relatively expensive medium-sized coffee – pushes you to pay out more money than you would have rationally chosen. “If you frame options in a certain way, you can nudge people in the direction of higher-priced products,” says Linda Chang, a psychologist at Harvard University.

Keep reading: https://www.bbc.com/worklife/article...ign=pockethits