Using Administrative Data to 

Examine Cross-program 

Participation in SNAP and WIC

Leslie Hodges, Laura Tiehen, & Erik Scherpf
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Disclaimer

The findings and conclusions in this presentation 

are those of the author(s) and should not be 

construed to represent any official USDA or U.S. 

Government determination or policy.
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WIC Background

• WIC provides nutritious foods, nutrition 

counseling, and health referrals 

• Target group: Low-income (<185% FPL) pregnant 

and postpartum women, infants, and children up 

to age 5

• Growing body of evidence that WIC is associated 

with improved dietary intake among children 

• Growing concerns about declines in WIC 

participation
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SNAP Background

• SNAP provides households with means to 

purchase healthy and nutritious foods via an EBT 

card

• Target group: SNAP is available to all households 

that meet the program’s income and asset 

criteria, subject to certain work and immigration 

status requirements

• Like WIC, not all eligible individuals participate 

(coverage rate is about 82%)

• SNAP participants are adjunctively eligible for 

WIC
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WIC Participation Has Been Declining 

for a Decade

0

1

2

3

4

5

6

7

8

9

10

2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020

Millions of Participants

Total Women Infants Children
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Not a Fertility Story...

0

10

20

30

40

50

60

70

80

90

100

2010 2011 2012 2013 2014 2015 2016 2017 2018

1-Year- Old Children

2-Year- Old Children

3-Year- Old Children

4-Year- Old Children

WIC Coverage Rates by Participant Category: CY 2005–CY 2018 

• Source. Gray, K.F., K.M. Mathieu, P. Johnson, and L. Giannarelli. 2021. “National- and State-Level Estimates of WIC Eligibility and WIC 

Program Reach in 2018 With Updated Estimates for 2016 and 2017 Volume I.” USDA, FNS and Insight Policy Research. https://fnsprod.azureedge.net/sites/default/files/resource-files/WICEligibles2018-VolumeI.pdf 
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WIC Participation Declines as Children Age

98% 61% 48% 41% 27%

0

20

40

60

80

100

120

Infants Age 1 Age 2 Age 3 Age 4

Coverage Rates by Participant Category, 2018

• Source. Gray, K.F., K.M. Mathieu, P. Johnson, and L. Giannarelli. 2021. “National- and State-Level Estimates of WIC Eligibility and WIC 

Program Reach in 2018 With Updated Estimates for 2016 and 2017 Volume I.” USDA, FNS and Insight Policy Research. https://fnsprod.azureedge.net/sites/default/files/resource-files/WICEligibles2018-VolumeI.pdf 
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Reasons for Non-Participation in WIC

• [Tiehen & Jacknowitz, 2008] Pregnant women who 

participate in WIC are more likely

– to be non-Hispanic black or Hispanic

– to have less than a high school education

– to be younger

– to have never been married

– to participate in other assistance programs

– and to have income below the poverty line

• [Jacknowitz & Tiehen, 2010] Women who exited from WIC

– Breastfed for shorter durations (<6 mos.)

– Reported that it was too much effort and/or benefits were not 

worth the time (25%)

– Reported lack of transportation and/or scheduling issues (9%)
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Reasons for Non-Participation in WIC

• Recent work from LA County (Whaley et al. 2017) and

FNS’s ITFPS-2 reports supports findings from prior work

• Continued participation associated with

– Prenatal participation in WIC

– Breastfeeding duration

– More than one family member on WIC (parity)

– Medicaid enrollment

– Access to WIC education online

• Exists associated with 

– Beliefs about ineligibility

– Feelings that WIC is inconvenient

– Perceptions of no longer needing WIC
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Current Study

1. What percentage of infants and children in SNAP 

participant households also participate in WIC, and how 

do these percentages vary across children’s age groups?

[Descriptive Analyses]

2. How do the characteristics of infants and children who 

participated in both SNAP and WIC differ from those 

who participated in only one program? 

[Regression Analyses]

3. What was the effect of the decline of the real value of 

SNAP benefits that were temporarily boosted by the 

2009 ARRA on WIC participation? 

[Difference-in-Differences]
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Data

• Next-Generation Data Platform

• SNAP and WIC participation data from 3 states

– Covers approximately 5% of WIC and SNAP 

participants in 2020

– Cross-section analysis includes all 3 states

– Longitudinal analysis focuses on 1 state over 10-

year period
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Strengths

Overcomes issues 

of underreporting 

of program 

participation

Capture variation in 

participation rates 

at substate level

Easily identify 

eligible nonparticipants
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Percent of WIC participants reporting 

participation in Medicaid, SNAP, or TANF 

at certification, 1994 - 2018

0

10

20

30

40

50

60

70

80

90

1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018

Percent

Medicaid SNAP TANF

Note: SNAP refers to the Supplemental Nutrition Assistance Program. SNAP values may underestimate SNAP participation at 

certification because once an individual being certified reports participating in Medicaid--which confers adjunctive eligibility to

WIC--WIC clinics may not always follow up and ask about participating in SNAP. 

Source: Bartlett et al., (2002), Bartlett et al., (2007), Johnson et al., (2013), Kline et al. (2020). 
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Challenges 

Limited 

information

Detail and 

quality of 

measures 

varies

May not have 

all household 

members
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Summary & Conclusions

• WIC is an integral component of the USDA 

programs that promote nutrition security

• Rates of participation among eligible 

populations have been declining over the past 

decade.

• Our research will provide valuable information 

on the WIC participation rates of SNAP 

participants