band radios. Under such near-classical competitive conditions
one would not expect chronic nonpayment for additional services
(pickups and drops) or that one type of carrier would be con-
sistently favored over another due to the ability to secure
more complete market information.

 The conclusions reached by the Transportation Research
Center study team were arrived at largely from informal discus-
sions with carriers, brokers, and receivers rather than by the
use of statistical techniques. The theoretically surprising
nature of their conclusions led to a reexamination of these
issues in this current study.

 In the remainder of this section, largely nonempirical
work addressing the three objectives of this study is dis-
cussed. This is done to provide a rationale for the approach
which was taken and to familiarize the reader with the reasons
why these issues are of concern.




1. How rates change over distance

 In Figure 1 are presented three types of distance-rate
relationships: flat, linear, and less-than proportional or
tapering. Flat schedules are usually attributable to some form
of institutional influence. The U.S. Mail First Class Service
is a prime example. Letters are transported anywhere in the
nation for the same charge. Linear schedules are what one
would expect to find. Once the "fixed" or distance-unrelated
costs, such as pickup and delivery, are accounted for (in the
intercept) there may be little reason to suppose that driving
the 100th mile would be any less costly than the 1000th mile.
However, several researchers have noted that rates for regu-
lated motor carriers exhibit tapers over distance (Bresseler
and King, Pegrum, and Lockin). There are three principal rea-
sons for explaining rate tapers. First, different equipment
may be employed for hauls of different lengths (Bresseler and