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Validated Longitudinal Identifier


CPSIDV is a 15-digit numeric variable.


CPSIDV is an IPUMS CPS-created variable that uniquely identifies individuals across CPS samples. In addition to linking records across the CPS 4-8-4 rotation pattern, CPSIDV only makes links between those records whose SEX and RACE values do not change and whose AGE values change in expected ways over time.

CPSIDV is based on CPSIDP and so there are some structural similarities between them. The first six digits of CPSIDV are identical to CPSIDP - the four-digit year and two-digit month that the household was first in the CPS. Like CPSIDP, CPSIDV allows users to link a respondent appearing with a designated household roster line number (LINENO) across samples, based on the 4-8-4 rotation pattern.

Only records that link using CPSIDP that also have consistent race and sex values and age values that increase at least one but not more than two years over the course of the 16-month CPS rotation are linkable using CPSIDV. As a result, linkage rates using CPSIDV are slightly lower than those achieved using CPSIDP. However, linkages created with CPSIDV do not require the recommended post-linking verification steps recommended for use with CPSIDP links. Users should note that original, unharmonized values of age, sex, and race are used in the creation of CPSIDV. The procedure and validation criteria for creating CPSIDV are described in detail in A Holistic Approach to Validating Current Population Survey Panel Data.

CPSIDV may also be used to link ASEC respondents who are in the March Basic Monthly file to other months of CPS data. This linking is made possible by IPUMS through the creation of MARBASECIDP.

To get started using CPSIDV, users may want to sort their data file by CPSIDV and MISH to create a person-time file.

Users should take care when including the March Basic or ASEC as part of their linking. Respondents who are part of the ASEC oversample (as indicated by ASECOVERP) have a CPSIDV value of 0. For further information about the relationship between the March Basic and the ASEC, please see our additional documentation.


Because CPSIDV is based on CPSIDP, interruptions in linkability that impact CPSIDP also impact CPSIDV. For more details about CPSIDP creation and linking discontinuities in the 1976-1988 period, see Flood et al., 2020. For more details about CPSID from 1989 forward, see Drew et al., 2014.

Demographic variables used in creating CPSIDV change over time. CPSIDV bridges changes in age topcodes and race values between 1976 and the present. See Table 1 in Rodgers and Flood (2023) for details about bridging race codes and Table 2 in the same paper for details about bridging age topcodes.


  • All persons.


Years Jan Feb ASEC Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1976 X X X X X X X X X X X X X
1977 X X - X X X X X X X X X X
1978 – 2023 X X X X X X X X X X X X X
2024 X X - X X X X - - - - - -


This variable has no flags.

Unharmonized Variables

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