Monday, 27 April 2015

A field experiment at LHR


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?
  1. 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.)
  2. Social preferences: the sign is a nudge to counter travellers' "lift aversion".
  3. 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.
  4. Social heuristics: people mistakenly assume the escalator is faster, as it usually is in their experience. The sign corrects this.
This is a biased choice of example. In other situations, the first three explanations might be more plausible. Still, many lab experiments might be cases of 4, mistaken for cases of 2 or 3.

I first read the term "social heuristics" in this paper.