Is it possible to integrate the 4 1% files into one file?
IPUMS USA offers six samples from the 1970 Census, each containing records for 1% of the US population. The samples differ by the level of geographic detail identified (State, metro, and neighborhood) as well by questionnaire variant. While all Census respondents received the same short-form questionnaire, one-in-five households also responded to a long-form questionnaire with additional questions. There were two variants of the long-form questionnaire (i.e., Form 1 and Form 2). As a result, both Form 1 and Form 2 samples include data on the same set of core variables as well as a different set of additional variables for each form.
It is possible to pool together the three Form 1 1970 samples (or the three Form 2 samples) in order to create a 3% sample of the form one data since these samples are, for all practical purposes, mutually exclusive. This type of procedure is referenced on page 8 of the 1970 codebook. Additionally, since respondents received either the Form 1 or Form 2 questionnaire, samples across these different forms can also be pooled together. Please refer to this previous forum thread for more information as well as how to properly weight this type of pooled sample.
Hi Ivan,
Thank you very much for the detailed answer. This is very helpful. IPUMS makes an important contribution to research and it is greatly appreciated.
Oleh
In a message dated 1/9/2026 1:15:11 PM Eastern Standard Time, notifications@ipums.discoursemail.com writes: