SIPP is a complex longitudinal survey that is continually addressing sample attrition and nonresponse bias. The 2024 SIPP continued to face data collection complications because of increasing costs and a general lower-than average unit response rate nationally.
To monitor and improve data quality during collection, SIPP’s geographic primary sampling units (PSUs) are reviewed to identify areas that have insufficient representation (coverage). Adaptive design case prioritization and active field management are used to achieve both an increase in representativeness and ensure a minimum level of coverage.
Even with these data collection mitigations, the low unit response rate in the 2024 SIPP led to item response rates and coverage ratios that do not meet the Census Bureau’s Statistical Quality Standards.
The SIPP program creates weights designed to adjust for nonresponse and to control weighted counts to independent population estimates by age, sex, race, and Hispanic origin. However, the magnitude of the increase in (and differential nature of) nonresponse during 2024 data collection likely reduces their efficacy. Data users should be aware of this when working with 2024 SIPP data, including the longitudinal 2021, 2022 and 2023 Panel subsamples.
The SIPP program is undertaking work in several areas that will support the quality and scope of data and estimates the program produces in the future. First, the program is exploring administrative-record use in data processing, editing, and imputation to assess whether external distributions improve imputation and final data quality. In addition, SIPP is considering survey redesign options that will enable the program to address several issues that have grown over recent years. The ‘SIPP Seamless’ initiative is focused on shifting the survey to year-round interviewing to reduce the burden created by the hiring cycle. The initiative also aims to support multi-mode interviewing. These design changes focus on operational and content aspects of data quality, the respondent experience, the data product portfolio, and long-term program stability.
Additional information on nonresponse bias for data collected in calendar year 2024 will be available in the upcoming Nonresponse Bias Report for Calendar Year 2024 of the Survey of Income and Program Participation. More details about 2024 SIPP’s unit response rate, sample attrition, and item response rates for SIPP’s key estimates are available in the 2024 SIPP Source and Accuracy Statement.