This publication is based on the WIC Infant Feeding Practices Study (WIC-IFPS) sponsored by FNS. The WIC-IFPS is a one-year longitudinal study, which describes the infant feeding practices over the first year of life among a nationally representative sample of approximately 900 mothers who participated in WIC while they were pregnant.

FNS asked Mathematica Policy Research, Inc., (MPR) to assess the CPS estimates in relation to alternative estimates from the Survey of Income and Program Participation (SIPP), which collects longitudinal monthly income data.