The Current Population Survey (CPS), a large monthly survey administered by the Census Bureau, is not only designed to measure labor force participation and employment, but is also used to measure health insurance coverage. Health insurance coverage information is collected once each year through the Annual Social and Economic Supplement (ASEC), which is administered February through April. However, a RWJ brief reports that the manner in health insurance status was asked in the CPS may over-estimate uninsurance rates.
To address issues of recall and other errors, the CPS revised its health insurance question in the ASEC. Specifically, in the revised CPS: “the respondent is first asked about their current coverage and is then asked when that coverage began and if other coverage was held in any month from the start of the previous calendar year through the date of interview.”
Additionally, uninsurance was overestimated because only one person in the household answered all the questions for the whole household. In the revised CPS:
To improve accuracy without increasing respondent fatigue, a hybrid of the household and person level design was developed. Questions are first asked at the person-level with follow-up questions to determine if others in the household also have an identified coverage type. For the additional household members their coverage is verified, if already identified, and they are asked if they had any additional coverage. The full question series is only asked of additional household members if they have not had any coverage identified in the first-pass through the question series.
The CPS has also been updated for the post Obamacare world. Now, individuals are asked whether their coverage was purchased through a health insurance exchange and if their premiums are subsidized by the government.
For researchers who seek a more consistent time series where the health insurance question changes less frequently over time, other survey options include: the American Community Survey, the Medical Expenditure Panel Survey, and the National Health Interview Survey.