Deconstruction of the Time Trend in Health Insurance: A Look inside SIPP 2008 Health Insurance Rates

Amy Steinweg, U.S. Census Bureau

Health insurance coverage is an important aspect of population health in the United States. The Survey of Income and Program Participation (SIPP) is a nationally representative survey that provides longitudinal surveillance on health insurance coverage at a monthly level. However, this requires a complex system of data collection. This analysis presents new longitudinal health insurance estimates from the SIPP spanning May 2008 to March 2010. I present monthly estimates for uninsurance, private coverage, Medicare, and Medicaid, paying particular attention to children’s coverage, as well as the distribution by number of months insured. I then decompose these estimates and distributions into their constituent waves and subsample components, revealing the irregularities embedded within the aggregate numbers. By breaking down the trend lines by their constituent pieces, this analysis underscores both the challenges in collecting monthly longitudinal data and the importance of keen attention to sources of variation when interpreting these longitudinal patterns.