under way). These groups are missed at high rates in surveys relative to estimates derived from the decennial census because they are not reported as household residents. We note, however, that SIPP (and other household surveys) will necessarily overlook some population groups who may be particularly at risk of poverty, including the homeless and people in institutions. The decennial population census (see below) includes these groups, although coverage is far from complete.
RECOMMENDATION 5.1. The Survey of Income and Program Participation should become the basis of official U.S. income and poverty statistics in place of the March income supplement to the Current Population Survey. Decisions about the SIPP design and questionnaire should take account of the data requirements for producing reliable time series of poverty statistics using the proposed definition of family resources (money and near-money income minus certain expenditures). Priority should be accorded to methodological research for SIPP that is relevant for improved poverty measurement. A particularly important problem to address is population undercoverage, particularly of low-income minority groups.
To aid in making the transition to a SIPP-based series of official poverty statistics and to help evaluate that new series, it would be helpful for the Census Bureau to produce a concurrent time series of poverty rates from the March CPS on the basis of the proposed measure. Both the SIPP and the March CPS series should be extended backward to 1984, when SIPP was first introduced. Also for the foreseeable future, the Census Bureau should issue public-use files from both SIPP and the March CPS that include values for the thresholds under the new concept and estimates of disposable income (and its components) under the new resource definition. The availability of such files will enable researchers to conduct poverty analyses with either survey.
RECOMMENDATION 5.2. To facilitate the transition to SIPP, the Census Bureau should produce concurrent time series of poverty rates from both SIPP and the March CPS by using the proposed revised threshold concept and updating procedure and the proposed definition of family resources as disposable income. The concurrent series should be developed starting with 1984, when SIPP was first introduced.
RECOMMENDATION 5.3. The Census Bureau should routinely issue public-use files from both SIPP and the March CPS that include the Bureau's best estimate of disposable income and its components (taxes, in-kind benefits, child care expenses, etc.) so that researchers can obtain poverty rates consistent with the new threshold concept from either survey.