The March 2000 CPS added a question to verify that individuals who indicate they lack coverage are indeed uninsured.7 The uninsured on the CPS had historically been a “residual” of those who answered they did not have other coverage types.
Research from other surveys suggested that asking individuals directly if they were uninsured would capture more people with coverage, hence the decision to add a question directly verifying no coverage. As it turned out, the verification question, overall, finds about 8% fewer uninsured each year.
Given the addition of the verification question has increased the number of persons reporting insurance coverage, we have adjusted the CPS in years prior to 2000 to mimic the effect of the verification question in those years. That is, each insurance category was adjusted, by age group, to approximately represent what would have been picked up had the verification question been asked in the earlier years. The uninsured have been reduced, within age group, proportional to the effects of verification found on the March 2000 through March 2004 CPS files. They are then given the coverage profile of those found to have coverage only through the verification questions.
7 From 2004 ASEC Questionnaire: “I have recorded that (name/you) (was/were) not covered by a health plan at any time during 2003. Is that correct?”
"report.pdf" (pdf, 121.72Kb)