Calculated yield indicators (CYI)
One project's inflated yields warranted an investigation in order to identify and isolate villages that had circumvented a condition of the contract, that only production from the contracted area be sold. The method used to identify villages with some degree of accuracy was to analyse production by applying a calculated yield indicator (CYI). The indicator was modelled by using the filtered data from statistical regressions against yield using quantitative and qualitative (or categorial variable) information.
The CYI was applied to each of the 28 villages and calculations were made to determine how the observed yields deviated from the estimated value. The results, as presented in Table A2, indicated how much each village over- or under-produced. There was a wide variation between the actual yields (2 871 kg/ha) and those of the calculated yield indicator (1 864 kg/ha). The actual deliveries were 569 116 kg in excess of the CYI estimate, which was close to the visual estimates. Provided that its limitations are recognized, the CYI is one method that can statistically indicate the locations and extent of yield distortions
Table A1
Response (Y) and explanatory variables (x) for CYI
Variable |
Form |
Description and criteria |
Y Yield |
Quantitative |
Kg/ha |
x1 Ha/Farmer |
Quantitative |
Ha/farmer |
x2 Farmer/PC* |
Quantitative |
Farmer/PC |
x3 Ha/PC |
Quantitative |
Ha/PC |
x4 Nitrogen |
Quantitative |
Soil analysis |
x5 Phosphorus |
Quantitative |
Soil analysis |
x6 Potash |
Quantitative |
Soil analysis |
x7 Topography |
Qualitative |
1 = Steep |
x8 Management |
Qualitative |
1 = Indifferent |
x9 Seed bed |
Qualitative |
1 = Indifferent |
x10 Transplanting |
Qualitative |
1 = Indifferent |
x11 Harvesting |
Qualitative |
1 = Indifferent |
x12 Processing |
Qualitative |
1 = Indifferent |
x13 Rainfall Est. |
Qualitative |
1 = Unsatisfactory |
x14 Rainfall Dev. |
Qualitative |
1 = Unsatisfactory |
Source: Adapted from Eaton, C.S., (1998b: 182).
*Note: PC = Individual farmer's processing capacity.
Table A2
Calculated production yields versus actual production
Village |
Hectares |
Yields |
Production
|
|||
|
|
CYI |
Actual |
Estimated |
Actual |
Excess vs |
1 |
28.13 |
2 179 |
2 358 |
61 278 |
66 324 |
5 046 |
2 |
28.13 |
2 179 |
2 516 |
61 278 |
70 758 |
9 480 |
3 |
14.38 |
1 496 |
1 956 |
21 501 |
28 120 |
6 619 |
4 |
2.50 |
2 179 |
2 526 |
5 447 |
6 314 |
867 |
5 |
40.63 |
1 933 |
2 889 |
78 549 |
117 365 |
38 816 |
6 |
34.38 |
1 496 |
2 430 |
51 416 |
83 529 |
32 113 |
7 |
34.38 |
1 373 |
2 989 |
47 200 |
102 751 |
55 551 |
8 |
34.38 |
1 933 |
2 464 |
66 464 |
84 685 |
18 221 |
9 |
9.38 |
1 373 |
3 153 |
12 873 |
29 563 |
16 690 |
10 |
21.88 |
1 373 |
3 013 |
30 036 |
65 902 |
35 866 |
11 |
62.50 |
1 933 |
3 000 |
120 844 |
187 474 |
66 630 |
12 |
84.38 |
1 933 |
3 763 |
163 139 |
317 517 |
154 378 |
13 |
34.38 |
1 933 |
3 134 |
66 464 |
107 746 |
41 282 |
14 |
6.25 |
2 056 |
1 769 |
12 851 |
11 057 |
-1 794 |
15 |
1.88 |
2 056 |
2 910 |
3 855 |
5 457 |
1 602 |
16 |
2.50 |
1 373 |
3 136 |
3 433 |
7 840 |
4 407 |
17 |
2.50 |
2 056 |
1 683 |
5 140 |
4 208 |
-932 |
18 |
1.25 |
1 373 |
9 406 |
1 716 |
11 757 |
10 041 |
19 |
1.25 |
1 373 |
1 590 |
1 716 |
1 988 |
272 |
20 |
62.50 |
1 933 |
3 011 |
120 844 |
188 213 |
67 369 |
21 |
3.13 |
2 056 |
4 683 |
6 425 |
14 635 |
8 210 |
22 |
1.25 |
2 056 |
4 816 |
2 570 |
6 020 |
3 450 |
23 |
8.75 |
1 933 |
2 492 |
16 918 |
21 807 |
4 889 |
24 |
21.88 |
1 933 |
1 629 |
42 295 |
35 642 |
-6 653 |
25 |
4.38 |
2 616 |
2 539 |
11 447 |
11 106 |
-341 |
26 |
6.25 |
2 056 |
1 032 |
12 851 |
6 453 |
-6 398 |
27 |
9.38 |
1 933 |
2 115 |
18 127 |
19 829 |
1 702 |
28 |
2.50 |
2 616 |
3 311 |
6 541 |
8 277 |
1 736 |
|
|
565.00 |
1 864 |
2 871 |
1 053 218 |
1 622 337 |
569 116 |
Source: Adapted from Eaton, C.S.,1998: 201.