Page 13 - Azerbaijan State University of Economics

THE JOURNAL OF ECONOMIC SCIENCES: THEORY AND PRACTICE, V.70, # 1, 2013, pp. 4-22

additional cost to the total cost when applying one more unit of input. MFC equals

to the first derivative of TC (Equation 5).

MFC= 1.018*P NG + 5.66 (5)

Results and Discussion

By analyzing the 129 demonstrations with regression analysis in Excel, the

summary of the statistic results of corn yield and the three water approaches is

shown in table 2. Quadratic regression model is chosen for all the three approaches

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based on the high R value. Notably that the all the three models have no constant

since if the amount of total available water, irrigation application and PPET is zero,

no yield will be produced.

Yield-TW model

The first model is corn yield as a function of TW. Equation 6 shows the

regression model.

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Y corn = 10.755*TW -0.138*TW (6)

The Marginal Physical Product of TW in corn yield (MPPTW) is equal to the

firstderivative of corn yield with respect to TW. The Marginal Value Product of

TW (MVPTW) is obtained by multiplying the MPPTW by the price of corn

(Pcorn) (Equation 7).

MVPTW = (10.755 -0.276*TW)*P corn (7)

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