relationship between the two at the individual level. Between these two extremes, one could consider a large number of variations.
Underlying the hypothetical continuum of design options is a second continuum related to the costs of alternative design combinations; the analytic capabilities associated with the richest design come at the cost of higher expenditures for data collection. Regardless of the choices made with respect to mode, frequency, cross-sectional versus longitudinal design, and other design features, further research to understand the error properties associated with alternative design features is necessary to more fully inform the decision process with respect to the cost–error trade-offs.
The choice of data collection design options is not one unique to the Social Security Administration. Other federal agencies responsible for constructing a social indicator series or providing data for the purposes of public policy or funds management have struggled with similar dilemmas. For example, the Agency for Healthcare Research and Quality (AHRQ, formerly the Agency for Health Care Policy and Research), faced a similar design issue with respect to the provision of information concerning health care utilization, expenditures, and health insurance coverage. During the 1970s and 1980s the agency relied on periodic household data collection efforts, supplemented with provider records and administrative data, as the basis for producing estimates (e.g., the 1977 National Medical Care Expenditure Survey, the 1986 National Medical Care Utilization and Expenditure Survey). These detailed data, yielding themselves to years of alternative analyses, formed the basis of long-range policy guidance. However rich these data were, such a design did facilitate research related to understanding shifts in health care utilization or expenditure patterns. In recent years, the design has shifted toward continuous data collection, with a longitudinal panel (the Medical Expenditure Panel Survey, see www.ahrq.gov/data/mepsinfo). The shift toward a longitudinal data collection effort with an ongoing (continuous) rotating panel design both increased the analytic capabilities of the data and reduced the gaps in data needed for public policy.
As noted above, one of the choices for SSA is whether to sponsor its own ongoing surveys or to enter into partnership with other federal agencies to obtain a small set of measures.
In short, what are the administrative, financial, and technical staffing burdens of mounting an ongoing survey, and what is the scope of informational needs? If there are many features of the population that are not now being well described, then a separate SSA survey may easily be justified as a small fraction of the funds allocated to fulfill its mission.