Hello, I am a doctoral student seeking to understand the effect of disability on educational attainment via a sibling design study. I want to use the full-count 1910 and 1940 censuses. For the 1910 Census, what would be the most appropriate household variable that would then allow me to identify siblings within the same household?
Secondly, I have a series of covariates pertaining to 1910 but only one outcome variable (plus the HIK variable) in 1940. Do I extract the 1910 Census data separately from the 1940 one and unlink the ‘linked census’ button? Or is there a way to link them such that I only choose certain covariates in 1910 and the two for 1940?
Is there a way to identify the occ score pertaining to the father and/or mother for each sibling pair?
You can match siblings in each household by using the IPUMS constructed family interrelationship variables MOMLOC and POPLOC. Households are uniquely identified within each Census year with a SERIAL number; since SERIAL values are reused across years, they must be used together with the variable SAMPLE to identify households when pooling multiple years of data. Within each unique combination of SERIAL and SAMPLE, individuals with the same values for MOMLOC and/or POPLOC are inferred by IPUMS as being siblings.
The original Census data only indicates the relationship of each household member to the household head without providing information on the relationships between individuals who are not the household head. As a result, IPUMS creates family interrelationship variables to simplify the process of linking family members for users. You can read about our linking method in detail on the Family Interrelationships User Guide.These variables include MOMLOC, which reports the person number (PERNUM) of the individual’s probable mother, and POPLOC, with the same for the individual’s probable father. This type of linking is only possible if the individual’s parent resides in the same household and cannot identify parents who are not recorded in the household roster. In cases where there is no mother/father to link to, our algorithm assigns a value of 0 for the corresponding variable. While there is no age limit for an individual to be linked to their co-resident parents (i.e., adult siblings living with their parents will still be identified), this method works best for matching younger siblings since it misses siblings who live together without their parents or whose parents have died. MOMLOC/POPLOC includes social relationships (such as stepfather and adoptive father) as well as biological relationships; STEPMOM/STEPPOP can be used to additionally differentiate between these cases. The rule used for a link between a parent and a child is provided in MOMRULE_HIST and POPRULE_HIST.
The attach characteristics tool allows users to add variables pertaining to an individual’s mother/father (as well as spouse and household head) as an additional variable on the individual’s record. For example, you can use the tool to add the variables OCCSCORE_MOM and OCCSCORE_POP, which will provide the OCCSCORE value for each person’s mother and father as identified in MOMLOC/POPLOC. This option is available on the Extract Options page after clicking View on your data cart and proceeding to create your extract. Only variables that have already been added to your data cart will appear as options in the attach characteristics tool. OCCSCORE_MOM/OCCSCORE_POP will be missing if there is no corresponding parent record to link to.
Currently, only 10-year links are available through the IPUMS USA extract system. Based on your description of wanting to link 1910 to 1940 directly, I recommend using the 30-year links through the MLP version 1.2 crosswalks. These crosswalks link HISTIDs (a consistent individual-level identifier) across full count samples by assigning linked records the same HIK. This allows you to sequentially merge each separate 1910 and 1940 data extract with the variables that you requested onto the crosswalk to obtain your linked data. For this method, do not utilize the “link census data” feature on the website. Please see this user guide for further details and sample code.