At Heathrow Terminal 2, there is an escalator and a lift to take you from the Underground up to departures. The authorities have put a sign up:
TIME ON ESCALATOR 3 MINUTES
TIME ON LIFT 58 SECONDS
TAKE THE QUICK ROUTE – TAKE THE LIFT
Why has this happened?
- Standard economics: the sign was a mistake. People already choose the optimal route. (Public choice theory: the sign was not a mistake but a deliberate conspiracy by the elevator company to wear out the lift and make money from replacements.)
- Social preferences: the sign is a nudge to counter travellers' "lift aversion".
- Social norms: there is a norm of taking the escalator. People really want to take the lift, but they are afraid what others will think of them.
- Social heuristics: people mistakenly assume the escalator is faster, as it usually is in their experience. The sign corrects this.
I first read the term "social heuristics" in this paper.