Hi, if I want to keep track of a person’s marital status and income as well as his/her spouse’s marital status and income, how should I choose the data? I now only get the data on two consecutive years. For example: from 2017-2018 because longitudinal data only has “1 year apart” option , but essentially I want to get the data from 2017-2018-2019-2020-2021-2022-2023. Thank you so much!
IPUMS has developed tools to simplify the process of linking respondents across CPS samples. One of these are longitudinal files, which link respondents across their two appearances in the Annual Social and Economic Supplement (ASEC). For example, records in the 2017-2018 linked ASEC file include all individuals who are in both the 2017 and 2018 ASEC files. Since respondents leave the CPS panel after 16 months, it is not possible to link respondents across more than two years of the CPS (i.e. you cannot link respondents from 2017-2023 because 2017 respondents were not interviewed in 2023). To add these longitudinal files to your extract, you will want to select longitudinal data files at the top of the Select Samples page. More information on these files is provided on the linked ASEC user note. IPUMS has also developed an Attach Characteristics tool (that can be accessed from the Extract request screen once you’ve clicked “view cart” and “create data extract”) which appends the respondent’s spouse’s income (INCTOT), marital status (MARST), or any other variable selected from the data cart as a new variable to the respondent’s line (mother’s, father’s and household head’s are also options). Currently, it is not possible to use both the longitudinal data files and the attach characteristics tool for the same extract. However, you can attach characteristics to a longitudinal file in any statistical package as long as you have added the variable SPLOC to your extract.
In Stata, you would run:
sort cpsid pernum_1
bysort cpsid : gen spouse_income_1=inctot_1[sploc_1]
sort cpsid pernum_2
bysort cpsid : gen spouse_income_2=inctot_2[sploc_2]
SPLOC reports the line number (PERNUM) of the respondent’s spouse. A person must be “married, spouse present” according to MARST in order to have a non-zero value for SPLOC, except for links between a householder and an unmarried partner. If you are only interested in married partners, you may identify and drop these links between a householder and an unmarried partner.
Note that the longitudinal ASEC files only include respondents who were surveyed in March. Given the CPS rotation pattern, only about 1/3 of respondents in any particular year will be surveyed in March (those entering the panel in December, January, February, or March). However, only respondents to the ASEC are asked about their personal income, so the ASEC is your best source for this data. If you want to analyze respondents in all Basic Monthly Survey (BMS) samples, you will have to do the linking yourself. IPUMS CPS provides extensive notes on how to accomplish this linking process in the 2021 Linking Workshop homepage, where you can also find Stata and R code. Note that the workshop will reference CPSIDP as the linking key and that users should validate their links; IPUMS CPS has since released the validated linking identifier CPSIDV. This new identifier only links respondents whose identities have been validated using SEX, RACE, and AGE and saves researchers the step of post-linking validation.