B [low], and C. These curves show the estimated annual clerk/carrier savings (in 1989 dollars) as a function of ZIP+4 usage for single-line OCRs and for multi-line OCRs with and without ZIP+4.
As discussed previously in the technical analysis, OTA concluded that the USPS estimate of 60 percent was pessimistic. OTA assumed that there was only a 5 percent chance that actual multi-line performance would be equal to or less than this low
OTA concluded that a reasonable median estimate of
performance was 65
percent, with a 50-50 chance that actual performance reasonable high estimate was 75 percent, with performance would equal or exceed this level.
or below, and that a chance that actual
The multi-line OCR savings curves associated with low (60 percent), median (65
percent), and high (75 percent) performance are shown in figure 8. OTA used the USPS multi-line OCR savings curve as the low performance curve (marked as Alt. B (low) in figure 8), and developed new savings curves for median and high multi-line OCR performance (marked as Alt. B [median] and Alt B. [high], respectively, in figure 8). The x-intercepts of the three multi-line curves (savings at O percent ZIP+4 usage) correspond to about 67, 73, and 83 percent of the single-line OCR savings at 90 percent ZIP+4 usage. Thus, based on this set of curves, at zero percent ZIP+4 usage the annual savings estimates are approximately $580 million, $635 million, and $720 million for the three multi-line OCR alternatives, as compared to about $230 million for the single-line OCR
calculated by dividing $580 million, the multi-line savings at O percent ZIP+4 usage,
$870 million, the single-line
savings at 90 percent ZIP+4 usage equals approximately the multi-line savings percentage at 65 percent and
by 67 75