D = demand for pickup and
 delivery services
 P = price for pickup and
 delivery
MR = marginal revenue
MC = marginal cost for pickup
 and delivery
L,s = subscripts denoting
 long and short hauls,
 respectively


S\D
 \ s


Figure 2.--Representation of price discrimination resulting from
 rate tapers across distance. (Adapted from Phlips,
 Chapter 2.)