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WIC Participation Patterns: An Investigation of Delayed Entry & Early Exit

by Laura Tiehen and Alison Jacknowitz

Economic Research Report No. (ERR-109) 45 pp, December 2010

What Is the Issue?

Despite the health benefits of participation, many eligible households do not participate in USDA's Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). While roughly half of infants born in the United States receive WIC benefits, USDA statistics indicate that eligible pregnant women and children 1-5 years of age are far less likely to participate in WIC than eligible infants and postpartum women. This implies that a number of pregnant women delay enrollment until after having a child, and that many households leave the program when a participating child turns 1 year old. Research on the factors that influence the dynamics of WIC participation can inform outreach and targeting efforts, so that vulnerable populations receive adequate exposure to the benefits of WIC participation.

What Did the Study Find?

There are notable differences in the timing of household participation in the WIC program.

  • Among the mother-child pairs (referred to as households) eligible for WIC, 79.1 percent
    participated in the program at some time during the period between the child's birth and when the child turned 1 year old (the "postnatal-infant period").
  • Of those who participated in the WIC program during the postnatal-infant period, 17.6
    percent did not enroll in the program until after the child was born and 22.9 percent exited the program when the child turned 1 year old.

Postnatal Enrollment in WIC

The following types of households were more likely than others to delay participating in WIC
until after their child was born:

  • Households with higher income and those with private insurance.
  • Households in which the mother has a college degree and was employed the year before
    giving birth.
  • Households in the Northeast and those in urban areas with a population of at least 50,000.

By contrast, prenatal Medicaid recipients were much less likely to delay WIC enrollment until
after having a child.

Exits From WIC

When a child turns 1 year old, the WIC household must recertify its eligibility for benefits. Roughly 90 percent of postnatal-infant participants retained eligibility after the child turned 1 year old. The following types of households were more likely than others to exit WIC after their child turns 1 year old:

  • Households with higher income.
  • Households in which mothers are more educated and were employed after the child's birth.
  • Mothers who did not breastfeed and those who breastfed for less than 6 months.

By contrast, households with income below the poverty line and those that participated in prenatal Medicaid were less likely to exit WIC after their child turned 1 year old. Approximately 33 percent of households that left the WIC program reported that they believed they were no longer eligible once the child turned 1 year old, and 27.8 percent reported that they no longer needed food benefits.

When a child turns 1 year old, the eligible WIC household no longer receives the infant food package, which contains infant formula for those who are not being breastfed exclusively, and transitions to the child food package, which has a significantly lower retail value. This change in WIC food benefits may play a role in a household's decision to exit WIC.

Although WIC is not an entitlement program, few households reported that they were denied benefits due to lack of program funds. Some households reported, however, that the program requires too much effort and the benefits are not worth the time (26.2 percent of those exiting) or that they have scheduling and transportation problems (almost 10 percent of those exiting), suggesting that such transaction costs of participation may be a barrier to continued participation in WIC.

How Was the Study Conducted?

Researchers used data from the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), a nationally representative longitudinal dataset of children born in 2001. The dataset provides demographic and economic information collected from the child's biological mother when the child is 9 months and 24 months old, as well as information from the child's birth certificate. The ECLS-B collects extensive information about the WIC participation of the mother and children in the household, and the timing of that participation. In addition, a subset of mothers who left the
WIC program was asked to report why they stopped receiving WIC benefits for their child.

The researchers used probit regression analysis to examine the factors that influence postnatal, rather than prenatal, enrollment in WIC and the factors that influence a household's exit from WIC once the child turns 1 year old. The researchers' analysis focused on the factors that influence a household's participation: perceived benefits, the stigma or transaction costs associated with participation, and the availability of information on the program and its eligibility
requirements. The researchers also used multinomial logit regression to examine WIC household characteristics that may have influenced WIC participants' self-reported explanation for leaving the program.


Last updated: Sunday, May 27, 2012

For more information contact: Laura Tiehen and Alison Jacknowitz