^aAll costs use market purchase-weighted prices estimated using 1999–2002 price data as described in Chapter 5—Evaluation of Cost. Data on number of participants were obtained from 2002 (Bartlett et al., 2003).

^bThe analyses presented in Tables E-4 and E-5 used published data for FY2002 from FNS (Bartlett et al., 2003, Exhibits 3.1 and 5.7) for the number of participants in total and in each participant category, including age groups within the infant category. The data presented by Bartlett et al. were derived from data collected on participants at the time of certification in the WIC program. If the analyses are done using the assumption that infant ages were distributed equally across twelve months, instead of by age at certification, the average package cost per participant would be $37.10 for the current packages and $38.02 for the revised packages. This represents an increase of $0.92 for the revised packages compared to the current packages. Thus, by these estimates the revised packages would be 2.5 percent higher in cost than the current packages. These estimates represent the upper bound of effects on costs because attrition in participation rates occurs as infants mature; for example, FY2002 enrollment was 2.1 million for infants and 1.4 million for one-year-olds (Bartlett et al., 2003). In using the data presented by Bartlett et al., the participant numbers throughout FY2002 were