Research and Review of the Extent and Nature of Underreporting of SNAP Participation in National Surveys

Project Overview

The principal objective of this project was to assess underreporting of Supplemental Nutrition Assistance Program (SNAP) participation in 4 national surveys—the Current Population Survey (CPS), the Survey of Income and Program Participation (SIPP), the National Health and Nutrition Examination Survey (NHANES), and the American Community Survey (ACS)—with the goal of identifying potential remedies for the problem. Underreporting has plagued household survey estimates of participation in SNAP and other programs that serve low-income populations, and recent evidence suggests that this problem is worsening. Because of the substantial number of people participating in SNAP and the large share of their income represented by the benefit, it is important that the datasets used to study poverty and the potential impacts of changes to program policy provide an accurate accounting of SNAP participation and benefit levels.

Insight’s work on this project included 4 main components:

  1. Review the research literature on underreporting in SNAP, other nutrition assistance programs, and other major assistance programs that serve low-income populations.
  2. Prepare estimates of underreporting of SNAP participation using the most recent data from 4 national surveys that are used extensively by the Food and Nutrition Service (FNS).
  3. Conduct additional analysis of the survey data to examine variation in underreporting by household characteristics, patterns of SNAP use, and aspects of questionnaire design and administration.
  4. Prepare a final report that combines the research review and empirical findings and discusses possible next steps.

The additional analysis of patterns of underreporting focused on the substantial decline in reporting of SNAP participation in the CPS; differences in the characteristics of reported SNAP participants in the SIPP, which has the lowest underreporting by far, as well as those in each of the other 3 surveys; and comparisons of the characteristics of SNAP participants recorded in SNAP Quality Control (QC) data and those reported in each of the 4 surveys.

Core Activities

Literature Reviews and Environmental Scans; Data Collection; Data Analysis and Simulations; Complex Survey Data Analysis Modeling; Database Development; Report Development and Presentation


The final report is entitled “The Extent and Nature of Underreporting of SNAP Participation in Federal Surveys.” (July 2012)