Environmental Engineering Reference
In-Depth Information
Table 11.1
Hypothetical results from agricultural questionnaire survey on
livestock production
Input into Livestock
Production
Amount of Inputs
Per Year
Amount of Livestock
Produced (kg)
Labour (hours)
200
63
Area (ha)
20
Labour (hours)
400
89
Area (ha)
20
Labour (hours)
200
100
Area (ha)
50
To identify the quantitative relationship between these variables, a
multiple regression analysis is carried out using the quantity of livestock
produced as the dependent variable and the input data as the independent
variables. The results of the multiple regression for this example are given
in Equation 11.2.
Q
l
5
L
l
0.5
A
0.5
R
2
5 1
(11.2)
The results could, of course, take an alternative form of production such
as a linear relationship shown below if the data i tted the multiple regres-
sion more accurately in this form.
Q
l
5 4.5
L
l
1 2
A
s
Clear and accessible information on the choice and understanding of dif-
ferent functional forms can be found in Hill et al. (1997).
Step 2: Calculating the value of livestock production
Once the production
function has been identii ed, the value of the ecosystem can be calculated
by estimating the value of the livestock products. Data are therefore
required on the price of livestock products and on the costs of production.
Again these data would be collected through a questionnaire survey, either
of the householders involved in production or through other individuals
who have knowledge of the markets.
Livestock costs data:
1.
What was the price of the livestock that was sold?
2.
How much of the livestock was retained for home consumption?
