“SNAP Participation Dynamics in a

Long-Term Administrative Data Panel

(in State X)”

Kegan O’Connor

USDA Economic Research Service

Agricultural Economist

FCSM Research and Policy Conference

October 26, 2023
2

Acknowledgements

• Co-authors: Laura Tiehen1, Maria Perez-Patron2, Christian A. Gregory1, Mark Prell1,

Michelle Ver Ploeg1

1USDA Economic Research Service; 2U.S. Census Bureau

• The findings and conclusions in this presentation are those of the authors and 

should not be construed to represent any official USDA or U.S. Census Bureau or U.S. 

Government determination or policy.

• The Census Bureau has ensured appropriate access and use of confidential data and 

has reviewed these results for disclosure avoidance protection (Project 7532295: 

CBDRB-FY24-CES005-001)
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SNAP: One Program—Two Populations

(or Three?)

SNAP serves two populations in a single program:

• Shorter term participants (measured in months)

• Longer term participants (measured in years)

A further complication: Some households cycle on and off SNAP

• They do not participate continuously for years at a time

• They do not exit the program permanently

• Cyclers are a third “type” of population
4

Motivation for Studying

SNAP Participation Dynamics

Broad motivation: To examine how SNAP operates as temporary assistance 

for some and longer-term source of support for others.

By examining entry, exit, re-entry, and spell durations, the study plans to:

• Identify characteristics associated with short and longterm participants

• Link participation dynamics to changes in SNAP caseload over that 

time
5

Background: SNAP by the Numbers

SNAP Administrative Data (aggregate)

• Average Monthly Participation: 41.2 million (FY 2022)

• Annual Federal Expenditure: $119.5 billion (FY 2022)

• Benefits per month, per person: $230.88 (FY 2022)

Survey of Income and Program Participation (SIPP) data (2008-2012)

• Median length of participation spell: 12 months

• Average length of participation spell: unknown (right censoring)
6

Background: SNAP by the Numbers

SNAP Administrative Data (aggregate)

• Average Monthly Participation: 41.2 million (FY 2022)

• Annual Federal Expenditure: $119.5 billion (FY 2022)

• Benefits per month, per person: $230.88 (FY 2022)

Survey of Income and Program Participation (SIPP) data (2008-2012)

• Median length of participation spell: 12 months

• Average length of participation spell: unknown (right censoring)

Remember this
7

SNAP Eligibility

• Eligibility is restricted to households with low income and low 

assets 

– State variation in income and asset tests

– Few nonfinancial criteria

• Rigorous process to establish and maintain eligibility

– Income and expenses are reported by applicant, with verification by 

caseworkers

– Eligibility must be re-established by applicant periodically

• Typically, every 6-12 months; 24 months for seniors
8

Prior Work on SNAP dynamics

• Series of SIPP-based analyses that examine dynamics and 

determinants of SNAP participation over a 4-5 year period. 

– Highlight the role of changes in earnings and family composition on SNAP 

participation dynamics

– Latest is Leftin et al. (2014) 

• State-level studies of micro-level administrative data.

– Highlight the role of recertification policy, including potential inefficiencies in the 

process

– Studies include Heflin et al. (2021), Homonoff and Somerville (2021), Ribar et al. 

(2008)
9

Strengths and Limitations of Data Sources

Large Federal surveys

Strengths

• Include participants and non-participants in 

sample

• Sample weights to ensure pop. representativeness

• Include a rich set of socio-economic data

• Include outcomes

Limitations

• Households underreport SNAP participation 

and benefits

• May lack any information on SNAP duration 

and benefits

State SNAP records

Strengths

• Include all SNAP participants (universe)

• Reliable detail on SNAP duration and benefits 

each month

• Long time series is feasible

Limitations

• Exclude non-participants

• Include only data needed to operate program

• No data on food security, health, other 

outcomes
10

SNAP Administrative Data for this Study

(Descriptive Analysis Today)

• SNAP administrative data from states representing different regions and different 

mixes of urban and rural areas

• Data and permissions obtained from three States, a fourth State is pending

• Today, results are from a Single State (unnamed at this time), highly preliminary

• Data acquired by partnership among Census Bureau, ERS, USDA’s Food and Nutrition 

Service (FNS), and State SNAP agencies
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SNAP Participation Dynamics and Methodology

Two methods to slice SNAP participants to analyze dynamics: 

• Cross-section (at moment in time, e.g., Month 1)—A and B are excluded from results today

• New Entrants (observe entry after Month 1)—C, D, E, and F are focus of results today 

Month

1 2 3 4 5 6 7 8 9 10 11 12

Total Time 

On

Cross Section for 

Month 1

Person A X X X X X X X X X X X X 12

Person B X X 2

New Entrants

Person C X X X X 4

Person D X X 2

Person E X X X X X X X X X "9"

Person F X X X X X X 6
12

SNAP Participation Dynamics and Methodology

• Dynamics of Cross-Section and New Entrants Differ

• Individuals in Cross-Section tend to be in middle of a long spell (“length-biased sampling”)

Month

1 2 3 4 5 6 7 8 9 10 11 12

Total Time 

On

Cross Section for 

Month 1

Person A X X X X X X X X X X X X 12

Person B X X 2

New Entrants

Person C X X X X 4

Person D X X 2

Person E X X X X X X X X X "9"

Person F X X X X X X 6
13

SNAP Participation Dynamics and Methodology

Total Time On = Cumulative number of months on SNAP (continuous or not) in 60 months

Note: Figure is for 12 months; actual data analysis is for 60 months

Month

1 2 3 4 5 6 7 8 9 10 11 12

Total Time 

On

Cross Section for 

Month 1

Person A X X X X X X X X X X X X 12

Person B X X 2

New Entrants

Person C X X X X 4

Person D X X 2

Person E X X X X X X X X X "9"

Person F X X X X X X 6
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SNAP Participation Dynamics (New Entrants)

Spell Type = Single Short-Term 

= Person has one spell in 60 months, lasting 8 months or less 

Examples: Person C and D

Note: Spell Length is affected by end of sample period (month 60) when right-censored 

Month

New Entrants Spell Type 1 2 3 4 5 6 7 8 9 10 11 12

Total Time 

On

Person C Single Short-Term X X X X 4

Person D Single Short-Term X X 2

Person E Single Long-Term X X X X X X X X X "9"

Person F Cycler X X X X X X 6
15

SNAP Participation Dynamics (New Entrants)

Spell Type = Single Long-Term 

= Person has one spell in 60 months, lasting 24 months or more

Examples: Person E

Note: Spell Length is “9” in 12-month figure; actual long-term spells are 24+ months

Month

1 2 3 4 5 6 7 8 9 10 11 12

Total Time 

On

New Entrants Spell Type

Person C Single Short-Term X X X X 4

Person D Single Short-Term X X 2

Person E Single Long-Term X X X X X X X X X "9"

Person F Cycler X X X X X X 6
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SNAP Participation Dynamics (New Entrants)

Spell Type = Multiple Spells (person is a “Cycler”)

= Person has more than one spell in 60 months

Examples: Person F

Month

1 2 3 4 5 6 7 8 9 10 11 12

Total Time 

On

New Entrants Spell Type

Person C Single Short-Term X X X X 4

Person D Single Short-Term X X 2

Person E Single Long-Term X X X X X X X X X "9"

Person F Multiple Spells X X X X X X 6
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Fig. 1. Dist’n of Total Time on SNAP (New Entrants)

State X, 2014-2018

30.2

19.1

13.2

21.5

16.0

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

1 - 8 months 9 - 16 months 17 - 24 months 25 - 48 months 49 - 60 months

Percentage
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Fig. 1. Dist’n of Total Time on SNAP (New Entrants)

State X, 2014-2018

30.2

19.1

13.2

21.5

16.0

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

1 - 8 months 9 - 16 months 17 - 24 months 25 - 48 months 49 - 60 months

Percentage About 30 percent of SNAP participants 

receive SNAP for 8 months or less 

out of 60 
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Fig. 1. Dist’n of Total Time on SNAP (New Entrants, SNAP units)

State X, 2014-2018

30.2

19.1

13.2

21.5

16.0

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

1 - 8 months 9 - 16 months 17 - 24 months 25 - 48 months 49 - 60 months

Percentage About 16 percent of SNAP participants 

receive SNAP for somewhere between 

49 to 60 months in total 

(perhaps across multiple spells)

About 30 percent of SNAP participants 

receive SNAP for 8 months or less

out of 60 
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Fig. 2. SNAP Household Participation, 

by Type and Length of Spells, State X, 2014-2018

32.3

15.0

12.1

40.6

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

Single short-term

(1 - 8 months)

Single medium-term

(9 - 23 months)

Single long-term

(24+ months)

Multiple spells

Percentage
21

Fig. 2. SNAP Household Participation, 

by Type and Length of Spells, State X, 2014-2018

32.3

15.0

12.1

40.6

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

Single short-term

(1-8 months)

Single medium-term

(9 - 23 months)

Single long-term

(24+ months)

Multiple spells

“Different” SNAP Populations

Served Within One Program

Percentage
22

Fig. 2. SNAP Household Participation, 

by Type and Length of Spells, State X, 2014-2018

32.3

15.0

12.1

40.6

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

Single short-term

(1-8 months)

Single medium-term

(9 - 23 months)

Single long-term

(24+ months)

Multiple spells

Short-Termers: 

About 1/3 of SNAP units 

have a single, short spell

Percentage
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Fig. 2. SNAP Household Participation, 

by Type and Length of Spells, State X, 2014-2018

32.3

15.0

12.1

40.6

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

Single short-term

(1-8 months)

Single medium-term

(9 - 23 months)

Single long-term

(24+ months)

Multiple spells

Long Termers:

About 1/8 of SNAP units 

have a single, long spell

Percentage
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Fig. 2. SNAP Household Participation, 

by Type and Length of Spells, State X, 2014-2018

32.3

15.0

12.1

40.6

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

Single short-term

(1-8 months)

Single medium-term

(9 - 23 months)

Single long-term

(24+ months)

Multiple spells

Cyclers: 

About 2/5 of SNAP units 

have multiple spells

Percentage
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Fig. 3. Cumulative Dist'n of SNAP Spell Lengths, 

State X, 2014-2018

16.3

30.5

50.8

64.0

75.0

100.0

0

20

40

60

80

100

6 months 12 months 24 months 36 months 48 months 60 months
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Fig. 3. Cumulative Dist'n of SNAP Spell Lengths, 

State X, 2014-2018

16.3

30.5

50.8

64.0

75.0

100.0

0

20

40

60

80

100

6 months 12 months 24 months 36 months 48 months 60 months

Median spell length is 24 months;

DOUBLE the SIPP-based estimate 

of 12 months
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Fig. 4. Cumulative Dist’n of Elapsed Time to SNAP Re-entry, 

Among all Re-entering Spells, State X, 2014-2018

69.1

85.5

91.7 95.1

100.0

0.0

20.0

40.0

60.0

80.0

100.0

6 months 12 months 18 months 24 months 25 months

or more
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Fig. 4. Cumulative Dist’n of Elapsed Time to SNAP Re-entry, 

Among all Re-entering Spells, State X, 2014-2018

69.1

85.5

91.7 95.1

100.0

0.0

20.0

40.0

60.0

80.0

100.0

6 months 12 months 18 months 24 months 25 months

or more

Given re-entry to SNAP, 

chances are high return will 

be within 12 months, 

or even 6
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Key Findings

• SNAP serves vulnerable populations with distinct needs for 

both short- and long-term assistance

• Among new SNAP entrants between 2014-2018, over the 60-

month study period

• 30% received SNAP for 8 months or less

• 16% received SNAP for 49-60 months

• 40% experience multiple spells
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Key Findings

• SNAP participation is dynamic, and administrative data suggest 

longer spell lengths than those found in survey data.

– The median spell length is 24 months

– If re-entry occurs after a SNAP exit, the majority (69%) will occur 

within 6 months and most (85%) within 1 year.
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Future Work

• Bring in additional States to the analysis

• Identify characteristics associated with short and longterm participants

• Link participation dynamics to changes in SNAP caseload 

over that time

• Analyze spell duration changes, for which groups, in response to:

— macroeconomic conditions across two decades

— COVID-19 pandemic
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You Can Request Data Access

• Federal and non-federal researchers can request permission to access micro-level 

SNAP data, and other restricted-use data, through the Standard Application Process 

(SAP)

• SAP Application Portal: https://www.researchdatagov.org/

• NOTE: Physical access to the data is through a Federal Statistical Research Data 

Center (FSRDC)
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Thank you!

Kegan O’Connor

USDA Economic Research Service

Kegan.O’Connor@usda.gov