Am trying to do an analysis of how state level policy changes impacted voter turnout using the November voter supplement. Key to the identification strategy is going back in time and having as many individual-level covariates as possible to test heterogenous effects on an individual’s turnout. A few questions about the November supplement:
(1) IPUMS is missing 1972 and 1974 although ICPSR has those years. Is there anything to be cautious of in using the ‘72 or ‘74 data (i.e., did IPUMS exclude those cross sections for reasons of concern about the data quality)?
(2) State identifiers. I assume that only state of residence is available and not state of birth as in other CPS surveys, but wanted to confirm.
(3) Are there any ways to link the CPS voter supplements to get more demographic variables. Especially interested in respondents’ parents levels of education, class, or occupation.
Thanks in advance for any insight you can provide.
The IPUMS CPS team has not processed these supplement samples as a result of prioritizing more recent samples; they are not aware of any inherent issues with the data.
Birthplace (BPL) is available in all CPS samples from 1994-onwards, but it does not provide additional detail beyond the country of birth. I am not aware of any CPS supplements that report the state of birth; this detail is however available in the ACS and Decennial Census samples on IPUMS USA.
Linking across CPS samples is constrained based on the CPS rotating panel structure (refer to the RoPES tool for a visual display of the panel). Households enter the CPS and are surveyed monthly for four months. Afterwards, they take an eight month break and then finish their time in the CPS with an additional four monthly surveys. As a result, it is possible to link persons across a maximum of eight appearances in the CPS; IPUMS CPS has created the unique person-level identifier CPSIDP and the validated identifier CPSIDV for this purpose. However, linking across supplement panels will likely not provide much additional details about respondents’ parents demographic characteristics. There are two main reasons for this: (a) the respondent must reside together with their parent in order for the parent to be identified and their characteristics linked to their child, and (b) the CPS surveys people residing in a selected housing unit and does not follow respondents when they move out of that unit. Linking across supplement panels will only yield additional details about the respondent’s parent if the parent does not reside with the respondent during the Voter supplement but does during one of the other seven samples that the respondent is surveyed in.
When a parent and their child do reside in the same household, they will be identified using IPUMS family interrelationship variables. POPLOC reports the person number (PERNUM) of the respondent’s coresident father and MOMLOC reports the PERNUM value of the respondent’s coresident mother. Researchers can use the attach characteristics tool to leverage these links and add new variables to the child’s record that report their parents’ values for selected variables. For example, if you have EDUC in your data cart, you can request that your extract includes each respondent’s coresident father’s EDUC value as a new variable called EDUC_pop. FBPL and MBPL (father’s and mother’s place of birth) are the only variables that I am aware of that directly report a demographic characteristic of respondents’ parents regardless of whether they reside together.
Thank you, Ivan. Very helpful. I appreciate it.