The Welfare Effects of SNAP Expansion
This paper investigates how raising income eligibility thresholds for the Supplemental Nutrition Assistance Program (SNAP) impacts enrollment among households that were already eligible, and evaluates whether these expansions increase overall social welfare.
Takeaway: Expanding SNAP eligibility increases enrollment among families who were already eligible, largely because broader rules boost overall awareness of the program.
Key Points
The Woodwork Effect is Real: For every newly eligible person who signs up after a SNAP eligibility expansion, nearly one previously eligible person also enrolls.
Information Trumps Stigma: The surge in enrollment is primarily driven by improved program awareness rather than a reduction in social stigma.
Welfare Gains: Because eligibility expansions help uninformed low-income households access benefits they were missing, relaxing SNAP limits generates significant net benefits for society.
Why do millions of low-income Americans who qualify for food assistance never actually receive it? Safety net programs often struggle with incomplete take-up—eligible families leave money on the table due to complex rules, application hurdles, or lack of awareness.
When policymakers discuss expanding welfare programs, they usually focus on the families at the financial margin who will become newly eligible. But changes to program rules often ripple backward to people who were eligible all along.
Understanding these spillovers helps answer a broader practical question: How can governments effectively design assistance programs to reach the people who need them most?
Research
Economists Jenna Anders and Charlie Rafkin examined whether loosening SNAP eligibility rules induces previously eligible households to apply—a phenomenon known as the "woodwork effect."
To test this, the authors analyzed USDA administrative data tracking state-level SNAP enrollment from 1996 to 2016. Because states adopted policy changes relaxing income limits at different times, the authors could compare enrollment trends among low-income households in states that expanded eligibility against those that did not. They combined this policy analysis with a nationally representative survey experiment and government survey data to uncover the underlying psychological and informational drivers behind people's decisions to enroll.
Findings
The researchers found strong evidence of a woodwork effect. Raising a state’s SNAP gross income threshold by 10 percentage points of the Federal Poverty Level (FPL) increased enrollment among already-eligible households by about 1.2 percent.
Nationwide, the overall impact is substantial: for every single person who joins SNAP because they became newly eligible under expanded rules, roughly 0.99 already-eligible people enroll as well.
To understand why this happens, the authors tested two main mechanisms:
Stigma Reduction: Does making a program available to higher earners make participating feel less embarrassing?
Information Frictions: Does expanding eligibility simply make the program more visible and easier to learn about through word-of-mouth?
While an online survey experiment showed that higher eligibility thresholds slightly decrease perceived social stigma, historical survey data revealed that program awareness was the dominant driver. The demographic groups showing the largest "woodwork" enrollment boosts were those with the lowest baseline awareness of SNAP rules, rather than those whose feelings of stigma were most sensitive to policy changes.
Limitations and Implications
Calculating whether these policy changes improve societal welfare requires making standard economic assumptions about how much society values income redistribution and how individuals weigh application hassles. Furthermore, the findings show that the woodwork effect brings in households that are slightly higher up the income ladder within the eligible pool, meaning the intervention isn't perfectly targeted to the very poorest non-participants.
Why It Matters
If these findings are correct, eligibility limits do far more than define who qualifies—they act as informational beacons. When evaluate safety net reforms, policymakers often view expanding eligibility as a trade-off between fiscal costs and helping moderate-income families. This research shows that expanding eligibility also serves as an effective, if indirect, tool for solving information barriers, helping the lowest-income households access assistance they were already legally owed.
Learn More
Paper Title: The Welfare Effects of Eligibility Expansions: Theory and Evidence from SNAP
Authors: Jenna Anders and Charlie Rafkin
Journal: American Economic Journal: Economic Policy
Publication Year: 2026
URL: https://www.aeaweb.org/articles?id=10.1257/pol.20220738
Econ Today Explains
Economic Concept: The Woodwork Effect
The "woodwork effect" refers to a phenomenon where a change in policy or eligibility criteria for a public program causes an increase in enrollment among individuals who were already eligible under the old rules—people coming "out of the woodwork."
Originally documented in health insurance policy (such as Medicaid expansions under the Affordable Care Act), woodwork effects occur because public announcements, media coverage, and community discussions surrounding a policy change increase broad awareness. For economists evaluating public finance, accounting for woodwork effects is essential because unintended enrollment shifts among previously eligible groups can significantly alter both the total budgetary cost and the overall social benefits of a policy reform.
This article was written by AI but reviewed by a real human.
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