Public Use Microdata Sample Files
Data Note 1

TECHNICAL NOTE ON SAME-SEX UNMARRIED PARTNER DATA
FROM THE 1990 AND 2000 CENSUSES

The release of data from the 2000 census has brought with it a number of analyses documenting change that has occurred since the last census was conducted in 1990. While many of the variables and processes between the two censuses are comparable, some are not, and direct comparison of some estimates may lead to misleading conclusions. This note discusses one such topic, that of ''unmarried partners,'' and advises that for some analyses-those involving unmarried same-sex partners-direct comparison of the 1990 and 2000 estimates is not substantively valid.  

The household relationship item in both the 1990 and the 2000 censuses offered many ways of identifying how other people in the household were related to the householder (the person in whose name the house is owned or rented). Categories included spouse, child or other relative of the householder, housemate/roommate, roomer/boarder, and unmarried partner.  In all circumstances, the respondent was asked to choose the category that best represented how other members of the household were related to the householder.  

In both censuses, the ''spouse'' and ''unmarried partner'' response categories were defined and asked the same way. However, there were important differences in data processing that mean that some of the data are not comparable, limiting the usefulness of comparisons of the number of same-sex unmarried partners between these two censuses. 

In both censuses, if a person was identified as the ''spouse'' of the householder and was the same sex as the householder, the ''spouse'' response was flagged for further review and allocation, that is, assignment of a value other than that originally reported, based on other data on the form. In 1990, the edit and allocation procedures did not allow same-sex ''spouse'' combinations to occur, thus resulting in the allocation of one of these two items in order to achieve editing consistency among the responses.  

Processing steps were changed for Census 2000 for households that contained same-sex ''spouses.'' If the person with the ''spouse'' category was the same sex as the householder and if neither person had their sex previously allocated, a relationship response of ''spouse'' was allocated as an ''unmarried partner'' response. Data allocation is a standard statistical practice that is followed by most data collection agencies. Data on the relationship item (as other items) were subject to allocation in the census, as they are in virtually all Census Bureau surveys.

Two principal factors affected our decision to take this approach for Census 2000.

1. Marriage Act (H.R. 3396) passed by the 104th Congress. This act instructs all 
  federal agencies only to recognize opposite-sex marriages for the purposes of 
  enacting any agency programs.  In order for Census Bureau data to be 
  consistent with this act and the data requirements of other federal agencies, 
  same-sex spouse responses were invalidated. The legislation defines marriage 
  and spouse as follows:

  ''In determining the meaning of any Act of Congress, or of any ruling, 
  regulation or interpretation of the various administrative bureaus and 
  agencies of the United States, the word 'marriage' means only a legal union 
  between one man and one woman as husband and wife, and the word 'spouse' 
  refers only to a person of the opposite sex who is a husband or wife.''  In
  order for the Census Bureau to be consistent with this act and the data 
  requirements of other federal agencies, same-sex ''spouse'' responses were 
  invalidated.

2. The second factor took into consideration that couples in long term same-sex 
  relationships may consider themselves as ''married partners'' and thus respond 
  as such on the census form. In addition, at the time of writing the editing 
  program for Census 2000, there were several challenges in the courts 
  concerning the legality of same-sex marriages. Clearly, we could not ignore 
  the fact that same-sex spouse responses were going to be recorded during 
  Census 2000. In light of these social and legal aspects and the lack of a key 
  variable in the statistical allocation routine (marital status) the assignment 
  of same-sex ''married'' couples to the same-sex ''unmarried partner'' category 
  was the procedure chosen for the editing process. We were adverse to a 
  randomized allocation of these responses after people had clearly marked a 
  close relationship preference on the census form.

  As a result of these changes in the processing routine, estimates of same-sex 
  unmarried partners are not comparable between the 1990 and 2000 census. We 
  believe 2000 census estimates of this category are better estimates than those 
  produced in 1990. It should also be noted that estimates of opposite-sex 
  unmarried partners, however, were not affected by these editing procedures and 
  changes and are comparable between the two censuses.

For further information on this topic, please contact the Fertility and Family Statistics Branch on 301-763-2416.


                                                             March 2003