WHY NOT WALK UP AN ESCALATOR?
APPLYING THE CONCEPTS #2: How do people think at the margin?
Why do people walk up stairs, but do not walk up escalators?
▪ On stairs, if you stand still you get nowhere
▪ On an escalator, you can stand and get there slower or walk and get there faster
▪ The cost of walking is the same either way. We can use the Marginal Principle to
determine if it makes sense to walk up the escalator.
▪ Suppose you are on the way to listen to a free concert, and you would be willing to
pay $10 for the ticket.
▪ There is a long staircase and you would pay up to $3 to avoid it. Walking the
staircase is therefore worth $7, $10 - $3.
▪ The next week there is the same opportunity, but with an escalator.
▪ You can stand and get the $10 value or Walk up the escalator and arrive sooner, but
with a $3 walking cost.
The marginal principle would say walk up the escalator if the extra music you hear is
worth the $3 extra cost incurred.