Annex 7

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 2 = Undulating 3 = Flat x8 Management Qualitative 1 = Indifferent2 = Modest 3 = Above Average x9 Seed bed Qualitative 1 = Indifferent2 = Modest 3 = Above Average x10 Transplanting Qualitative 1 = Indifferent2 = Modest 3 = Above Average x11 Harvesting Qualitative 1 = Indifferent2 = Modest 3 = Above Average x12 Processing Qualitative 1 = Indifferent2 = Modest 3 = Above Average x13 Rainfall Est. Qualitative 1 = Unsatisfactory2 = Satisfactory 3 = Good x14 Rainfall Dev. Qualitative 1 = Unsatisfactory2 = Satisfactory 3 = Good

Source: Adapted from Eaton, C.S., (1998b: 182).

*Note: PC = Individual farmer's processing capacity.

Table A2
Calculated production yields versus actual production

 VillageCode Hectares Yields Production CYI(kg/ha) Actual(kg/ha) Estimated (kg) Actual(kg) Excess vsCYI est. (kg) 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.