1940 CITY universe

https://usa.ipums.org/usa-action/variables/CITY#comparability_section

I’m using the 1920, 1930, and 1940 complete count files. From the documentation site for the CITY variable (link above) for 1920 and 1930:

" 1920 and 1930: The city of residence is given for households in any city with 25,000+ inhabitants."*

But, there is no listing for the 1940 complete count. Is the universe the same as for the 1920 and 1930 files?

or does the 1940 universe the same as in the 1940 1% file?

“1940 1% and 1950: The city of residence is given for households located in central cities of metropolitan areas only if the metropolitan central city and the remainder of the metropolitan area each had a population of 100,000+”

Thanks,
Greg

This is a good question. The IPUMS Historical Census Team will be working on updating this documentation at some point in the future. Regarding the universe for the CITY variable in the 1940 file: The general threshold for identifying cities in the 1940 full count is 10,000 residents. There are some exceptions to this rule (mostly a handful of cities in New England and elsewhere that have population counts less than but close to 10,000). These exceptions are likely due to the fact that these places are identifiable in other census years.