Does the Current Population Survey Overstate the Number of Uninsured Americans

Several researchers have argued that the Current Population Survey (CPS) undercounts the number of individuals on public insurance and as a result overstates the number of individuals who are uninsured. This paper compares survey estimates from the CPS to estimates from the Medical Expenditures Panel (MEPS). The CPS estimates for both the size of the Medicaid and uninsured populations are above the full-year MEPS estimate but below the at-least-part-year MEPS estimate. The CPS does not appear to overstate the number of uninsured because CPS uninsured estimates are only slightly higher than MEPS full-year uninsured estimates and MEPS data clearly demonstrate that many people are uninsured for only part of the year.