Q2 Z2,(Q2) Z2(Q2) - Institute for Water Resources - U.S. Army

the coefficient for one river district it is possible to determine
the change in cost occasioned by increasing the proportion of total
output produced on that river district. This method provides a link
between all river districts for determining the effect on cost of
relative shifts in the firms operation from one part of the waterway
to another.
Detailed records of the firm's shipments were obtained for
the three years in the sample. These records provide information on
the number of tons and ton-miles of each commodity carried by the
firm. The sample firm carried over sixty different commodities
each year as detailed by the I.C.C. "Standard Commodity Classification
for Transportation." Due to the small sample size it was necessary
to aggregate the commodities in some fashion.
Freight can be loosely classified into bulk freight and
general cargo. Bulk freight is perhaps best characterized by
commodities which can be dumped or poured into a barge. Bulk
commodities represent the "bulk" of the traffic handled by the
barge industry. General cargo is freight which has undergone some
processing and is usually "packaged" In some way.
This two-fold classification, however, obscures some
important differences. Bulk commodities, for example, coma in both
liquid and solid form. Coal, usually carried under long term
contracts which specify frequency of delivery, is often carried
in unit tows (i.e., with equipment "dedicated" to that particular
traffic). Equipment used in unit tows can be scheduled separately
from the rest of the firm's traffic. Special cleaning and
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