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

Howe estimates both kinds of functions. His production function
uses monthly time-series data for three firms representative of different
operating conditions on the Mississippi River System. The production
function estimated was:
(S) TM = aoB a le 2 p
where: TM = cargo ton-miles
B = equivalent barge days underway, full and empty
H = operating horsepower hours
The log-linear form of the function was estimated. Note that the inputs
are measured as flows. The function was estimated separately for each
firm.
Howe's planning function uses combined cross-section, time-series
data for six firms. The estimated function was:
(9) TM = ace l liP c42Ta3 p
where: TM = annual cargo ton-miles
B = number of equivalent jumbo barges owned or leased
by the firm
T = time (1950 = 01, 1962 = 13)
Once again the log-linear form of the function was estimated. The inputs
are measured as stocks.
The results for the production function exhibited reasonable pro-
perties for two of the firms in the sample. The coefficients of H and
B were significant for these firms and showed constant 'or slightly in-
creasing returns to scale for the capital input. The third firm had
neither significant coefficients nor reasonable parameter estimates
(the sign of the barge input was negative).
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