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

1962 counterparts. However, only (1) was significantly different in
1957 from its 1962 version; the others were not significantly differ-
ent as between 1957 and 1962. These results supported the conclusion
that significant changes had occurred since 1950 in the production re-
lationships used by Class A inland waterway carriers operating on the
Mississippi River.
The production and planning functions just discussed, both those
of Howe and those of Hurter, referred to the activities of an entire
firm, as contrasted with the production function for a tow. Theoret-
ically, cost functions for the firm could be developed from a know-
ledge of the appropriate unit costs of each input and the appropriate
planning or production function. This procedure, however, was not
used by Hurter in his study of cost relationships for inland waterway
operations. 12 Rather, his method was that of statistically relating
costs to output or some other measure of firm size. Hurter's empiri-
cal cost study made use of annual cross-section data for Class A car-
.
riers operating on the Mississippi River System in 1950, 1957, and
1962.
The first sot of equations estimated by Hurter involved regres-
sing total annual waterline expenses on total annual tonnage. The
proportion of the variance explained by these regressions was very
low for 1950 but over 60 percent for both 1957 and 1962. Hurter con-
fined his equations to a log-linear form for reasons discussed in his
paper. All of the equations indicated economies of scale. Signifi-
cant differences were found in the extent of the scale economies when
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