Due to the complex sampling design for the CPS, users of IPUMS-CPS data must make use of weights to produce representative statistics. The choice of weight depends on the particular sample being analyzed.
Most analyses based on individual-level ASEC data should use the ASECWT variable. ASECWT is based on the inverse probability of selection into the sample and adjustments for the following factors: failure to obtain an interview; sampling within large sample units; the known distribution of the entire population according to age, sex, and race; over-sampling Hispanic persons; to give husbands and wives the same weight; and an additional step to provide consistency with labor force estimates from the basic survey. ASECWT is the person-level weight that is available for questions that were not part of the basic monthly survey questions asked every month in the CPS.
For analyses of the ASEC focused on household-level variables, researchers should use the household weight, ASECWTH. ASECWTH generally has the same value as ASECWT for the household head or reference person. As noted above, vacant housing units and households that could not be interviewed due to residents' absence or refusal to participate have a value of zero in ASECWTH.
Starting in 2005, the Census Bureau calculated household and person weights using more age detail for children. These calculations, which produce the official weights used in the ASEC for 2005 and later, provide better estimates of children by single year of age. The Census Bureau also recalculated the weights for the 2004 ASEC based on these changes. For the 2004 ASEC, IPUMS-CPS makes available both the original weights (ASECWTH, ASECWT) and the new weights (ASECWTH04, ASECWT04).
Basic Monthly Weights
Analysts using data from the Basic Monthly files should use the variable WTFINL to weight their data (or HWTFINL for household-level variables). Variables that are part of the Outgoing Rotation Group (Earner Study) should be weighted using EARNWT.
Non-ASEC Supplement Weights
For non-ASEC supplements, research are advised to use the particular supplement weight. A comprehensive list is provided below. Note that the naming convention for weights changed in 2018 (see IPUMS-CPS Weights Renaming 2018).