How are missing months of birth assigned in the 1900 full count?

USA
1

Hello, I couldn’t find this documented anywhere about the 1900 full count census so apologies if it’s already been answered. I know from examining the census manuscripts that there are often cases of people with their birth month recorded as “Un” or blank, but in the downloadable sample, there are no cases of birth months that aren’t the 12 actual months. So were these cases all dropped from the sample? or were they filled in somehow?

Thanks for any clarification!

2

As a general policy, IPUMS USA allocates every missing or illegible value in the full count collection as described in our guide to data editing and allocation. Data quality flag variables are provided to indicate which cases have been edited/allocated (see QBIRTHMO). The detailed information on the allocation procedures provides the following information for BIRTHMO:

BIRTHMO:
Month of birth (P)
Flag Name: QBIRTHMO
Universe of Donors:
1870, 1880 & 1950: Persons under age 1 with an unallocated BIRTHMO entry
1900: All persons with an original (unallocated) BIRTHMO entry

Predictor Variables:
AGEMONTH

Procedures:
Assign the same value of BIRTHMO as the previous person who matches the subject on AGEMONTH (1870 and 1880).
If AGEMONTH is not available, assign the same value of BIRTHMO as the previous person in the universe.

Flag Value: 4

As described above, missing and illegible values for BIRTHMO in the 1900 full count are assigned from a nearby donor who has an original unallocated entry. This donor is typically a member of the same household, but can also be from one or two households over in the enumeration order. This method takes into consideration evidence of some birth clustering among siblings, though the allocation is less informative when the month is allocated from someone outside of the household.