ulations). The CPS questions of key pertinence to SHADAC are asked in the Annual Social and Economic Supplement (ASEC) portion of the CPS, which can suffer from nonresponse; Call suggested that ASEC responses have to be imputed in their entirety for roughly 10 percent of respondents each year. A thornier problem with the CPS is that the form of the key questions is intended to yield calendar-year estimates of health insurance coverage, but not necessarily contemporaneous estimates. A facsimile of the questions on the 2011 ASEC4 indicates that “these next questions are about health insurance coverage during the calendar year 2010. The questions apply to ALL persons of ALL ages.” The lead question is then: “At any time in 2010, (was/were) (you/anyone in this household) covered by a health insurance plan provided through (their/your) current or former employer or union?” Hence, the question is not quite as precise as a measure of current coverage and does not capture lapses in coverage.
What changed in 2008 was the addition of a health insurance question to the ACS, and that has had tremendous benefit for analyzing health coverage. A major benefit of the ACS question is asking about coverage at the time of the survey, in contrast to a calendar year reference period and long look-back requirement for coverage in the CPS questions. The ACS version of the question—“Is this person CURRENTLY covered by any of the following types of health insurance or health coverage plans?”—emphasizes current coverage; it permits yes/no answers to seven types of insurance coverage, plus a write-in category.5 However, there is a new interpretation challenge presented by ACS estimates—explaining, for instance, what an estimate of current health insurance coverage means in an average computed over 1, 3, or 5 years of data. Call suggested another challenge inherent in the ACS data, stemming from its development as a general survey and not as a dedicated barometer of health and health insurance trends. Specifically, the unit embodied in each ACS questionnaire—a household, or a “census family” unit—is not necessarily the same thing as a health insurance unit. By its nature, the ACS does not probe to identify relationships within the household/family that would allow access to an individual’s health plan (a policy holder and their dependents), and so that relationship cannot be directly recovered.
But, Call argued, the drawbacks of the ACS for examining health coverage are outweighed by the most profound benefit of the ACS relative to the CPS: its larger sample size, roughly 15 times that of the CPS in a given year, and its representativeness for smaller geographic and demographic units within states. Combined with the full range of covariate information available in the ACS, the larger sample size of the ACS has enabled analysis at finer, substate levels that
4See http://www.census.gov/apsd/techdoc/cps/cpsmar11.pdf [July 2012], pp. D-77–D-78. The questions are asked through computer-assisted interviewing, hence the syntax choices in the phrasing of the question; the question shown on the CPS interviewer’s screen reflects previously collected information.
5This question is numbered Person Question 16 in the 2012 version of the questionnaire.