1940 NYC Enumeration District issue

I’ve extracted 1940 full data for New York City, using STATEICP/CITYICP and including variable ENUMDIST. However, when I look at the data, some of the enumeration districts seem not to match up to actual EDs. For example, ED 3100369 isn’t found in the data, but ED 3103690 is—but 3690 is not an actual ED for Manhattan. (I’ve confirmed that 3103690 doesn’t exist by checking the actual microfilmed images.)

Can I assume 3103690 is the same as 3100369?

Dear Arlene,

IPUMS adds a digit at the end of the Enumeration District code to accommodate EDs that include an alphabetic character. If an ED has no alphabetic character, the ED code ends in a zero. If the ED contains an alphabetic character, we convert the character to a number based on its location in the alphabet (e.g., A == 1, B == 2, C == 3).

Thus, based on the way IPUMS codes enumeration districts, ED 3103690 is the same as 3100369. Essentially, if you observe a 0 in the right-most digit of the ED code, you can drop it to get the ED code you would observe on the microfilmed images. If you observe a non-zero digit, convert it to an alpha character.

Dave Van Riper
IPUMS Research Scientist

Thank you—I couldn’t find anything in the notes for ENUMDIST that indicates this. Is this true for all years? When I look at 1920 it doesn’t seem to be the case, as ENUMDIST 61004530 doesn’t exist but ENUMDIST 61000453 does.

Dear Arlene,

The trailing zero only applies to the 1940 enumeration district codes. It does not apply to the other years.


Thank you!