The primary data sources for this report are the Current Population Survey (CPS), the Survey of Income and Program Participation (SIPP), the Panel Study of Income Dynamics (PSID), and administrative data for the AFDC/TANF, SNAP, and SSI programs. Wherever possible, the current report includes updated estimates for indicators and risk factors through 2011.
For our key measures of receipt, dependency and poverty at a single point in time, the report primarily uses the Annual Social and Economic Supplement to the CPS, which measures income and poverty over an annual accounting period. The release of CPS data is timely and CPS data have the added benefit that they may be analyzed with the Transfer Income Model (TRIM3) to correct for the underreporting of welfare program receipt and benefits that is often present in survey data. TRIM3 is a microsimulation model developed by the Urban Institute under contract to the Office of the Assistant Secretary for Planning and Evaluation. Welfare caseloads in TRIM3 are based on CPS data, adjusted upward to ensure that total estimates of recipients equal the total counts from administrative data. To maintain consistency in data trends in this report, we present estimates based on CPS data analyzed by TRIM3 beginning in 1993, the first year the TRIM3 microsimulation model became available.
For indicators and risk factors that capture the monthly dynamics of welfare receipt over time, we use the SIPP. The SIPP collects monthly survey data on income and program participation among individuals and families across the country in panels that last roughly three to four years. While the CPS collects data on the incidence of welfare program receipt and poverty in a given year, the SIPP allows us to present monthly data on how long individuals and families receive welfare assistance and how long they remain poor over a time span of several years. The current report includes updated estimates for most of the SIPP measures based on newly available data from the 2008 SIPP panel, spanning from 2008 to 2011.
The Panel Study of Income Dynamics (PSID) is another source of data used in this report. Like the SIPP it provides longitudinal data, but over a much longer time period than the three- to four-year time period of each SIPP panel. With annual data on program receipt since 1968, the PSID provides vital data for measuring longer-term welfare use over periods of up to 10 years. Because the PSID indicators cover time spans as long as a decade, they are updated less frequently than the CPS-based and SIPP-based measures.
The report also draws upon administrative data for the AFDC/TANF, SNAP, and SSI programs. These data are largely reported in Appendix A. Like the CPS data, administrative data are available with minimal time lags; for the current report, administrative data are generally available through fiscal year (FY) 2011. To the extent possible, TANF administrative data are reported in a consistent manner with data from the earlier AFDC program, as noted in the footnotes to the tables in Appendix A. Assistance under locally designed TANF programs encompasses a diverse set of cash and non-cash benefits designed to support families in making a transition to work, and so direct comparisons between AFDC receipt and TANF receipt should be made with caution. This issue also affects reported data on AFDC and TANF receipt in national data sets such as the CPS, SIPP, and PSID.
For further technical information about the data presented in the report please see Appendix D.