We obtain counts of the number of people participating in the Supplemental Nutrition Assistance Program (SNAP), formerly known as the Food Stamp Program, from the United States Department of Agriculture, Food and Nutrition Service (USDA/FNS). SNAP is a low-income assistance program that is uniform in eligibility requirements and benefit levels across states, with the exception of Alaska and Hawaii, where benefit levels and income eligibility requirements are higher, and with the exception of broad-based categorical eligibility, which can vary by state.

We use county-level counts of participants for the month of July in the estimation process. The county-level SNAP variable is controlled to a state-level SNAP variable. We calculate the number of recipients by state as a 12-month average. The counts of individual participants in the SNAP program for some counties are unavailable or have values that seem implausible. In either of these cases the raw SNAP count is not used in the SAHIE models. For these cases, the SAHIE model itself supplies estimates for the missing values.

For states, we adjust isolated extreme values so that they are compatible with long-term trends. Outliers often result from special SNAP issuance in response to natural disasters. These special programs relax the usual eligibility criteria for a short period of time. We remove these additional recipients with the adjustments. We also remove the additional recipients resulting from a different income eligibility standard in Alaska and Hawaii. We obtain estimates of the number of recipients in these states who would not be eligible in the continental United States from the "Characteristics of SNAP Households" survey of the USDA/FNS.

For more information see the Supplemental Nutrition Assistance Program at the USDA.