December 31, 2012: The SHADAC Data Center has been updated to include 2011 American Community Survey (ACS) insurance estimates.
The ACS is a household survey that began in 2005 and produces annually updated data on a variety of population characteristics, including health insurance coverage. The ACS began asking survey respondents about health insurance coverage during the 2008 calendar year. Visitors to the Data Center can use 2011 estimates to create multi-state overview tables, detailed state-level tables, or trends across states.
SHADAC has issued a chart book using the new ACS data: "State-Level Health Insurance Estimates from the 2011 American Community Survey." The maps and tables included in the report provide state-level insurance
coverage estimates for the nonelderly population (age 0 to 64), children (age 0 to 18), and nonelderly adults (age 19 to 64). Within each age group, we also present separate estimates for the low-income population (people with family incomes at or below 200 percent of federal poverty guidelines).
Revisions to the SHADAC-Enchanced Current Population Survey (CPS)
The Data Center has also been updated to include revised SHADAC-Enhanced CPS estimates for calendar years 2000 to 2009.
The CPS uses population controls based on the 2000 Census for calendar years 2000 to 2009 while using population controls based on the 2010 Census for calendar years 2010 and 2011. This approach can lead to disjointed estimates if assumptions of population growth do not hold (although the difference between the Census 2000-based population controls and the Census 2010-based population controls is the smallest overserved in recent decades). To ensure a consistent time series, we averaged the SHADAC-Enhanced CPS estimates for 2000 to 2009 so that they occur linearly across years based on actual population growth as determined by the 2010 Census.
More information about the Census 2010-based population controls is available in Appendix E of this Current Population Report from the Census Bureau.
 The SHADAC-Enhanced CPS health insurance coverage estimates are CPS data reweighted and adjusted to account for historical changes in the survey’s methodology. SHADAC recommends using the enhanced CPS data for trend analysis. For more information, see “SHADAC-Enhanced CPS Health Insurance Coverage Estimates: A Summary of Historical Adjustments.”